Science of Synthesis: Houben-Weyl Methods of Molecular Transformations Vol. 32 (eBook)

Science of Synthesis – Volume 32: X--Ene--X (X = F, Cl, Br, I, O, S, Se, Te, N, P), Ene--Hal, and Ene--O Compounds 1
Title page 3
Imprint 5
Preface 6
Volume Editor's Preface 8
Overview 10
Table of Contents 14
Introduction 36
32.1 Product Class 1: 1,3-Bis(heteroatom-substituted) Allenes and Analogous Higher Cumulenes 48
32.1.1 Product Subclass 1: 1,3-Dihaloallenes 48
32.1.1.1 Synthesis of Product Subclass 1 48
32.1.1.1.1 Method 1: Synthesis Using Alkyllithium Reagents and Pyran-2-ones 48
32.1.2 Product Subclass 2: 1-Halo-3-(organooxy)allenes 50
32.1.3 Product Subclass 3: 1-Halo-3-(organochalcogeno)allenes 50
32.1.3.1 Synthesis of Product Subclass 3 50
32.1.3.1.1 Method 1: Synthesis Using Sulfonoselenoate Reagents and Alkynes 50
32.1.4 Product Subclass 4: 1-Nitrogen-Functionalized 3-Haloallenes 51
32.1.5 Product Subclass 5: 1-Phosphorus-Functionalized 3-Haloallenes 52
32.1.6 Product Subclass 6: 1,3-Bis(organooxy)allenes 52
32.1.7 Product Subclass 7: 1-(Organochalcogeno)-3-(organooxy)allenes 52
32.1.7.1 Synthesis of Product Subclass 7 52
32.1.7.1.1 Method 1: Synthesis Using Silyl Ketene Reagents and Alkynes 52
32.1.8 Product Subclass 8: 1-Nitrogen-Functionalized 3-(Organooxy)allenes 53
32.1.9 Product Subclass 9: 1-Phosphorus-Functionalized 3-(Organooxy)allenes 53
32.1.10 Product Subclass 10: 1,3-Bis(organochalcogeno)allenes 53
32.1.11 Product Subclass 11: 1-Nitrogen-Functionalized 3-(Organochalcogeno)allenes 54
32.1.12 Product Subclass 12: 1-Phosphorus-Functionalized 3-(Organochalcogeno)allenes 54
32.1.13 Product Subclass 13: 1,3-Bis(nitrogen-functionalized) Allenes 54
32.1.14 Product Subclass 14: 1-Nitrogen-Functionalized 3-Phosphorus-Functionalized Allenes 54
32.1.15 Product Subclass 15: 1,3-Bis(phosphorus-functionalized) Allenes 54
32.1.16 Product Subclass 16: 1.-Bis(heteroatom-functionalized) Cumulenes 55
32.2 Product Class 2: Monofunctionalized Allenes and Higher Cumulenes 58
32.2.1 Product Subclass 1: Haloallenes 58
32.2.1.1 Synthesis of Product Subclass 1 59
32.2.1.1.1 Method 1: Fluoroallenes by Fluoride Substitution with Organocuprates 59
32.2.1.1.2 Method 2: Chloroallenes by Isomerization of Propargylic Chlorides 60
32.2.1.1.2.1 Variation 1: Using a Copper(I)/Copper(0) Catalyst 60
32.2.1.1.2.2 Variation 2: Using Only a Copper(I) Catalyst 61
32.2.1.1.3 Method 3: Chloroallenes from Propargylic Alcohols and Thionyl Chloride 61
32.2.1.1.4 Method 4: Chloroallenes from Propargylic Alcohols and Hydrogen Chloride 62
32.2.1.1.5 Method 5: Flash-Vacuum Thermolysis of 1-Chlorocyclopropenes 62
32.2.1.1.6 Method 6: Chloroallenes from Benzyne and Propargyl Chloride 63
32.2.1.1.7 Method 7: Chloroallenes from Ketene Silyl Acetals 63
32.2.1.1.8 Method 8: Chloroallenes from Alkynes and Benzil 64
32.2.1.1.9 Method 9: Chloroallenes from Propargylic Alcohols and Titanium(IV) Chloride 65
32.2.1.1.10 Method 10: Bromoallenes by Alkynylogous Ring Opening of Oxiranes 66
32.2.1.1.11 Method 11: Bromoallenes by Copper-Mediated Nucleophilic Substitution of Propargylic Methanesulfonates 67
32.2.1.1.12 Method 12: Bromoallenes from Acid Chlorides 67
32.2.1.1.13 Method 13: Bromoallenes from Phosphonium Bromides 68
32.2.1.1.14 Method 14: Iodoallenes from Propargylic Alcohols 69
32.2.1.1.14.1 Variation 1: Activation of the Propargylic Alcohol by a Phosphonium Species 69
32.2.1.1.14.2 Variation 2: Using a Copper(I)/Copper(0) Catalyst 69
32.2.2 Product Subclass 2: (Organochalcogeno)allenes 70
32.2.2.1 Synthesis of Product Subclass 2 70
32.2.2.1.1 Method 1: Isomerization of Propargyl Ethers by Potassium tert-Butoxide/tert-Butyl Alcohol 70
32.2.2.1.2 Method 2: Isomerization of Propargyl Ethers by Potassium tert-Butoxide/Pentane 71
32.2.2.1.3 Method 3: Isomerization--Elimination of Propargyl Ethers by Potassium tert-Butoxide/Benzene 72
32.2.2.1.4 Method 4: Metalation of Alkoxyallenes and Addition to Aldehydes 72
32.2.2.1.5 Method 5: Alkylation of the Intermediate Obtained from Acylsilanes and Acetylides 73
32.2.2.1.6 Method 6: Wittig Alkenation of Chromium--Carbene Complexes 74
32.2.2.1.7 Method 7: Alkylation--Isomerization of Propargyl Sulfides 75
32.2.2.1.8 Method 8: Allenyl Sulfides and Selenides by the Wittig Route 76
32.2.2.1.9 Method 9: Allenyl Sulfides by a Three-Component Reaction 77
32.2.2.1.10 Method 10: Allenyl Sulfides by Palladium-Catalyzed Coupling 78
32.2.3 Product Subclass 3: Nitrogen-Functionalized Allenes 78
32.2.3.1 Synthesis of Product Subclass 3 78
32.2.3.1.1 Method 1: Allenyl Amides by Base-Catalyzed Rearrangement 78
32.2.3.1.2 Method 2: Morpholinoallenes by Conjugate Addition 79
32.2.3.1.3 Method 3: 4-Vinylideneoxazolidin-2-ones by Palladium Catalysis 80
32.2.3.1.4 Method 4: Copper-Catalyzed Coupling of Allenyl Halides with Amides, Carbamates, and Ureas 81
32.2.3.1.5 Method 5: Rhodium-Catalyzed Coupling of Propargylic Carbonates and Sulfonamides 83
32.2.4 Product Subclass 4: Phosphorus-Functionalized Allenes 84
32.2.4.1 Synthesis of Product Subclass 4 85
32.2.4.1.1 Method 1: Isomerization of Propargylphosphines under Basic Conditions 85
32.2.5 Product Subclass 5: Monofunctionalized Cumulenes 85
32.2.5.1 Synthesis of Product Subclass 5 85
32.2.5.1.1 Method 1: Wittig Route to Bromobutatrienes 85
32.2.5.1.2 Method 2: Elimination/Deprotonation/Regioselective Reprotonation 87
32.3 Product Class 3: 1,2-Bis(heteroatom-substituted) Alkenes 92
32.3.1 Product Subclass 1: 1,2-Dihaloalkenes 92
32.3.1.1 Synthesis of Product Subclass 1 93
32.3.1.1.1 Method 1: Synthesis by Oxidation of Arenes or Hetarenes 93
32.3.1.1.1.1 Variation 1: Oxidation of 3,4-Dibromo-2,5-bis(phenylsulfanyl)furan 93
32.3.1.1.1.2 Variation 2: Oxidation of Halogenated Azatriquinacenes 93
32.3.1.1.1.3 Variation 3: Oxidation of Phenols 94
32.3.1.1.1.4 Variation 4: Oxidation of Aniline 95
32.3.1.1.2 Method 2: Synthesis by Reduction 95
32.3.1.1.2.1 Variation 1: Reductive Defluorination 95
32.3.1.1.2.2 Variation 2: Reductive Dechlorination 96
32.3.1.1.2.3 Variation 3: Reductive Elimination of Mixed Halogen Atoms 97
32.3.1.1.2.4 Variation 4: Reductive Coupling 99
32.3.1.1.3 Method 3: Synthesis by Substitution 103
32.3.1.1.3.1 Variation 1: Substitution of Fluorine 103
32.3.1.1.3.2 Variation 2: Substitution of Chlorine or Bromine Atoms 104
32.3.1.1.3.3 Variation 3: Substitution of Halogens by Alkyl or Aryl Groups 114
32.3.1.1.3.4 Variation 4: Substitution of Oxygen 118
32.3.1.1.4 Method 4: Synthesis by Elimination 123
32.3.1.1.4.1 Variation 1: Dehydrofluorination 123
32.3.1.1.4.2 Variation 2: Dehydrochlorination 127
32.3.1.1.4.3 Variation 3: Dehydrobromination 129
32.3.1.1.4.4 Variation 4: Dehydroiodination 133
32.3.1.1.4.5 Variation 5: Elimination of Sulfur 134
32.3.1.1.4.6 Variation 6: Elimination with Fragmentation 135
32.3.1.1.5 Method 5: Synthesis by Addition 136
32.3.1.1.5.1 Variation 1: Addition of Methyl Hypofluorite to Allenes or Butadienes 136
32.3.1.1.5.2 Variation 2: Addition of Chlorine to Alkynes 137
32.3.1.1.5.3 Variation 3: Addition of Bromine to Alkynes 138
32.3.1.1.5.4 Variation 4: Addition of Iodine to Alkynes 142
32.3.1.1.5.5 Variation 5: Addition of Bromine Monofluoride to Alkynes 143
32.3.1.1.5.6 Variation 6: Addition of an Iodine and a Fluorine Atom to Alkynes 144
32.3.1.1.5.7 Variation 7: Addition of Halogen Chlorides or Halogen Bromides to Alkynes 147
32.3.1.1.5.8 Variation 8: Addition of Nucleophiles to vic-Dihaloquinones and Related Systems 150
32.3.1.1.5.9 Variation 9: Carbene Dimerization 152
32.3.1.1.6 Method 6: Synthesis by Cycloaddition 153
32.3.1.1.6.1 Variation 1: Synthesis by [2 + 2] Cycloaddition 153
32.3.1.1.6.2 Variation 2: Synthesis by [2 + 2 + 1] Cycloaddition 156
32.3.1.1.6.3 Variation 3: Synthesis by [3 + 2] Cycloaddition 157
32.3.1.1.6.4 Variation 4: Synthesis by [4 + 2] Cycloaddition 158
32.3.1.1.6.5 Variation 5: Synthesis by [5 + 2] Cycloaddition 167
32.3.1.1.6.6 Variation 6: Synthesis by [4 + 3] Cycloaddition 168
32.3.1.1.7 Method 7: Synthesis by Rearrangement 169
32.3.1.1.7.1 Variation 1: Migration of Fluorine 169
32.3.1.1.7.2 Variation 2: Cyclopropane Isomerization 170
32.3.1.1.7.3 Variation 3: Carbon Framework Rearrangements 172
32.3.1.1.7.4 Variation 4: Sigmatropic Rearrangement 174
32.3.1.1.7.5 Variation 5: Electrocyclic Reactions 174
32.3.1.1.7.6 Variation 6: Miscellaneous Rearrangements 176
32.3.1.1.8 Method 8: Synthesis from Alkenyl Compounds with Retention of C==C Bond Configuration 178
32.3.1.1.8.1 Variation 1: Boron Replacement 178
32.3.1.1.8.2 Variation 2: Silane Replacement 180
32.3.1.1.8.3 Variation 3: Silane Replacement with Rearrangement 181
32.3.1.1.8.4 Variation 4: Stannane Replacement 183
32.3.1.1.8.5 Variation 5: Hydroxyalkylation of (E)- or (Z)-Iodo(pentafluoropropenyl)zinc Intermediates 184
32.3.1.1.8.6 Variation 6: Zinc Displacement 185
32.3.1.1.8.7 Variation 7: Zinc/Copper Displacement 187
32.3.1.2 Applications of Product Subclass 1 in Organic Synthesis 188
32.3.2 Product Subclass 2: 1-Halo-2-(organooxy)alkenes 204
32.3.2.1 Synthesis of Product Subclass 2 204
32.3.2.1.1 Method 1: Synthesis by Oxidation and Reduction 204
32.3.2.1.2 Method 2: Synthesis by Substitution of a Leaving Group 206
32.3.2.1.3 Method 3: Synthesis by Substitution of a Metal 208
32.3.2.1.3.1 Variation 1: Substitution of Tin 208
32.3.2.1.3.2 Variation 2: Substitution of Rhodium (via Carbenoid Intermediates) 210
32.3.2.1.4 Method 4: Synthesis by Enolate Alkylation or Acylation 215
32.3.2.1.5 Method 5: Synthesis by Elimination 215
32.3.2.1.6 Method 6: Synthesis by Addition 220
32.3.2.1.6.1 Variation 1: Intermolecular Additions to Alkynes 220
32.3.2.1.6.2 Variation 2: Addition to Alkynes/Halocyclization 221
32.3.2.1.7 Method 7: Synthesis by C--C Bond Formation 224
32.3.2.1.7.1 Variation 1: Nazarov Cyclization 224
32.3.2.1.7.2 Variation 2: Cycloadditions 226
32.3.2.1.8 Method 8: Synthesis by Rearrangement 227
32.3.2.1.9 Method 9: Synthesis with Retention of the Functional Group 228
32.3.3 Product Subclass 3: 1-Halo-2-(organochalcogeno)alkenes 236
32.3.3.1 Synthesis of Product Subclass 3 236
32.3.3.1.1 Method 1: Synthesis by Oxidation 236
32.3.3.1.1.1 Variation 1: Oxidation of Aryl Sulfides or Sulfoxides 236
32.3.3.1.1.2 Variation 2: ß-Halogenation of Vinyl Sulfides 238
32.3.3.1.2 Method 2: Synthesis by Reduction 238
32.3.3.1.3 Method 3: Synthesis by Substitution 239
32.3.3.1.3.1 Variation 1: Replacement of a Halogen 239
32.3.3.1.3.2 Variation 2: Replacement of a Metal 241
32.3.3.1.4 Method 4: Synthesis by Elimination 243
32.3.3.1.5 Method 5: Synthesis by the Addition of Halogens to Allenes 244
32.3.3.1.5.1 Variation 1: Addition to Allenyl Sulfides or Selenides 245
32.3.3.1.5.2 Variation 2: Addition to Allenyl Sulfoxides with Concomitant Reduction 248
32.3.3.1.5.3 Variation 3: Addition to Allenyl Sulfoxides 249
32.3.3.1.5.4 Variation 4: Addition to Allenesulfinic Acids and Allenyl Sulfones 252
32.3.3.1.6 Method 6: Synthesis by Addition to Alkynes 253
32.3.3.1.6.1 Variation 1: Chloroalkylation of Selanylalkynes 253
32.3.3.1.6.2 Variation 2: Addition of Sulfenyl Halides to Alkynes 254
32.3.3.1.6.3 Variation 3: Addition of Selenenyl Halides to Alkynes 258
32.3.3.1.6.4 Variation 4: Addition of Tellurium Halides to Alkynes 260
32.3.3.1.6.5 Variation 5: Addition of Sulfonyl Halides to Alkynes 261
32.3.3.1.6.6 Variation 6: Addition of Sulfur(VI) Halopentafluorides to Alkynes 262
32.3.3.1.6.7 Variation 7: Addition of Tellurium(IV) Chloride to Propargyl Alcohols 264
32.3.3.1.7 Method 7: Cycloaddition 264
32.3.3.1.8 Method 8: Synthesis by Rearrangement 265
32.3.3.1.9 Method 9: Synthesis with Retention of the Functional Group 266
32.3.4 Product Subclass 4: 1-Nitrogen-Functionalized 2-Haloalkenes 270
32.3.4.1 Synthesis of Product Subclass 4 270
32.3.4.1.1 Method 1: Synthesis by Oxidation 270
32.3.4.1.1.1 Variation 1: ß-Halogenation of Enamines 270
32.3.4.1.1.2 Variation 2:a-Halogenation of Enamino Ketones 271
32.3.4.1.1.3 Variation 3: ß-Halogenation of N-Alkenylated Amides 277
32.3.4.1.1.4 Variation 4: ß-Halogenation of N-Vinylcarbamates 280
32.3.4.1.1.5 Variation 5: Synthesis of Enamino(phenyl)iodonium Salts 283
32.3.4.1.2 Method 2: Synthesis by Reduction 283
32.3.4.1.2.1 Variation 1: Reduction of Chlorides 283
32.3.4.1.2.2 Variation 2: Reduction of Aromatic Heterocycles 284
32.3.4.1.2.3 Variation 3: Reductive Alkylation 284
32.3.4.1.3 Method 3: Synthesis by Substitution 285
32.3.4.1.3.1 Variation 1: Substitution of Fluoride 285
32.3.4.1.3.2 Variation 2: Substitution of a Chlorine Atom Bonded to C3 of a Cyclopentenone 289
32.3.4.1.3.3 Variation 3: Substitution of Chlorine or Bromine Atoms Bonded to Heterocycles 291
32.3.4.1.3.4 Variation 4: Substitution of Iodine 294
32.3.4.1.3.5 Variation 5: Substitution of Hydroxy or Alkoxy Groups 296
32.3.4.1.3.6 Variation 6: Substitution of Acyloxy Functions 298
32.3.4.1.3.7 Variation 7: Synthesis of ß-Halovinyl Azides 300
32.3.4.1.3.8 Variation 8: Substitution of Silicon or Tin 301
32.3.4.1.4 Method 4: Synthesis by Elimination 302
32.3.4.1.5 Method 5: Synthesis by Addition 304
32.3.4.1.5.1 Variation 1: Additions to Allenes 304
32.3.4.1.5.2 Variation 2: Intermolecular Additions to Alkynes 304
32.3.4.1.5.3 Variation 3: Chlorocyclization of Alkynes 306
32.3.4.1.5.4 Variation 4: Bromo- and Iodocyclization of Alkynes 307
32.3.4.1.5.5 Variation 5: Vilsmeier Reactions 310
32.3.4.1.5.6 Variation 6: Condensations of a-Halo Ketones 311
32.3.4.1.6 Method 6: Synthesis by Rearrangement 312
32.3.4.1.6.1 Variation 1: Thermolyses of Cyclopropanes 312
32.3.4.1.6.2 Variation 2: Electrocyclic Ring Opening 312
32.3.4.1.7 Method 7: Synthesis with Retention of the Functional Group 313
32.3.4.1.7.1 Variation 1: Additions to Arenes 313
32.3.4.1.7.2 Variation 2: Additions to Hetarenes 314
32.3.5 Product Subclass 5: 1-Phosphorus-Functionalized 2-Haloalkenes 324
32.3.5.1 Synthesis of Product Subclass 5 324
32.3.5.1.1 Method 1: Synthesis by Substitution 324
32.3.5.1.1.1 Variation 1: Substitution of a Halogen 324
32.3.5.1.1.2 Variation 2: Substitution of a Metal 325
32.3.5.1.2 Method 2: Synthesis by Elimination 326
32.3.5.1.3 Method 3: Synthesis by Addition 327
32.3.5.1.3.1 Variation 1: Intermolecular Additions to Alkynes 327
32.3.5.1.3.2 Variation 2: Intramolecular Additions to Allenes 328
32.3.5.1.4 Method 4: Synthesis by Condensation 331
32.3.5.1.5 Method 5: Synthesis of 2-Chlorovinyl Dichlorophosphonates and Dichlorothiophosphonates 332
32.3.6 Product Subclass 6: 1,2-Bis(organooxy)alkenes 334
32.3.6.1 Synthesis of Product Subclass 6 335
32.3.6.1.1 1,2-Dioxyethenes 335
32.3.6.1.1.1 Method 1: Dehalogenation or Dehydrohalogenation of 1,2-Dialkoxy- or 1,2-Diaryloxy-1,2-dihaloalkanes 335
32.3.6.1.1.2 Method 2: Elimination of Alcohols from Acetals or Ortho Esters 340
32.3.6.1.1.3 Method 3: Selective Reduction of 1,2-Dialkoxyacetylenes 341
32.3.6.1.1.4 Method 4: Synthesis from 2-Acetoxyvinylmercury(II) Chlorides 341
32.3.6.1.1.5 Method 5: Synthesis from Carbenes and Related Species 342
32.3.6.1.1.6 Method 6: Carbonylation and Sulfanylation of 2,3-Dimethoxybuta-1,3-diene 345
32.3.6.1.1.7 Method 7: Synthesis of Polycyclic Systems Containing a 1,2-Dialkoxyethene Component 345
32.3.6.1.2 1,3-Dioxoles 346
32.3.6.1.2.1 Method 1: Addition of Diazomethane to a,ß-Dicarbonyl Compounds 346
32.3.6.1.2.2 Method 2: Synthesis from a-Diazocarbonyl Compounds 347
32.3.6.1.2.3 Method 3: Cathodic Reduction of 1,2-Diarylethanediones in the Presence of N-Arylcarbonimidic Dichlorides 349
32.3.6.1.2.4 Method 4: Synthesis from a-Hydroxy Ketones 349
32.3.6.1.2.5 Method 5: Synthesis by the Intermediacy of Carbenes or Their Equivalents 350
32.3.6.1.2.6 Method 6: Retro-Diels--Alder Reactions 352
32.3.6.1.2.7 Method 7: Synthesis from 1,3-Dioxolanes 353
32.3.6.1.2.8 Method 8: Modification of Other 1,3-Dioxoles 355
32.3.6.1.3 2,3-Dihydro-1,4-dioxins 356
32.3.6.1.3.1 Method 1: Synthesis from a,ß-Dicarbonyl Compounds 356
32.3.6.1.3.2 Method 2: Cycloannulation 356
32.3.6.1.3.3 Method 3: Cyclization of 2-(1,3-Dioxolan-2-yl)ethanols, Bis(2-hydroxyethyl) Ethers, or 2-(Propargyloxy)ethanols 357
32.3.6.1.3.4 Method 4: Fragmentation and Concomitant Recyclization of a 2,2'-Bioxirane 358
32.3.6.1.3.5 Method 5: Synthesis from 1,4-Dioxanes 358
32.3.6.1.3.6 Method 6: Synthesis from Other 2,3-Dihydro-1,4-dioxins 360
32.3.6.2 Applications of Product Subclass 6 361
32.3.6.2.1 Method 1: Cycloaddition Reactions 361
32.3.6.2.2 Method 2: Reactions of Metal Complexes or Lithium Salts 363
32.3.6.2.3 Method 3: Addition Reactions 364
32.3.6.2.4 Method 4: Polymerization 366
32.3.7 Product Subclass 7: 1-(Organochalcogeno)-2-(organooxy)alkenes 370
32.3.7.1 Synthesis of Product Subclass 7 370
32.3.7.1.1 Method 1: Synthesis by Substitution 370
32.3.7.1.1.1 Variation 1: Substitution of Haloalkenes 370
32.3.7.1.1.2 Variation 2: Substitution of Sulfonylalkenes 371
32.3.7.1.1.3 Variation 3: Synthesis from Alkylsulfanyl Ketones (Perkow-Type Reaction) 371
32.3.7.1.1.4 Variation 4: Synthesis from Bis(dialkylsulfonium) Salts 372
32.3.7.1.2 Method 2: Synthesis by O-Sulfonylation of Acyl Sulfonium Ylides 372
32.3.7.1.3 Method 3: Synthesis by O-Acylation of a-Alkylsulfanyl Derivatives 372
32.3.7.1.3.1 Variation 1: O-Acylation of a-Sulfonium Enones 372
32.3.7.1.3.2 Variation 2: Synthesis from a-Sulfonyl Ketones 373
32.3.7.1.3.3 Variation 3: Synthesis from Dihydrothiopyranones 373
32.3.7.1.3.4 Variation 4: Synthesis from a-Oxosulfonium Aldehydes 373
32.3.7.1.4 Method 4: Synthesis by O-Phosphorylation of a-Sulfanyl Enolates 373
32.3.7.1.5 Method 5: Synthesis from a-Chloro Ketones 374
32.3.7.1.6 Method 6: Synthesis from Alkynes 374
32.3.7.1.6.1 Variation 1: Synthesis by Halotosyloxylation 374
32.3.7.1.6.2 Variation 2: Addition of Alcohols to Alkynes 375
32.3.7.1.6.3 Variation 3: Synthesis by Electrophilic Cyclization of Acetylenic Aldehydes 375
32.3.7.1.6.4 Variation 4: Synthesis from Alkynylselenonium Salts 375
32.3.7.1.6.5 Variation 5: Synthesis from Alkynyliodonium Salts 376
32.3.7.1.6.6 Variation 6: Synthesis Using Dimethyl Sulfide Ditrifluoromethanesulfonate 376
32.3.7.1.6.7 Variation 7: Synthesis by Electrophilic--Nucleophilic Addition to Triple Bonds 377
32.3.7.1.6.8 Variation 8: Synthesis by Addition of O-Sulfenyl Arenesulfonates to Alkynes 377
32.3.7.1.7 Method 7: Synthesis from Allenes 378
32.3.7.1.7.1 Variation 1: Synthesis by Nucleophilic Addition 378
32.3.7.1.7.2 Variation 2: Synthesis by Inverse-Electron-Demand Diels--Alder Reaction 378
32.3.7.1.7.3 Variation 3: Synthesis from Thioaldehydes 378
32.3.7.1.8 Method 8: Synthesis from 1,2-Thiazetidine 1,1-Dioxide 379
32.3.7.1.9 Method 9: Synthesis from 2-(Methylsulfanyl)benzoxazole 379
32.3.7.1.10 Method 10: Synthesis by Double-Bond Migration 379
32.3.7.1.11 Method 11: Synthesis by Chain Elongation 380
32.3.7.1.12 Method 12: Synthesis by Cycloaddition 380
32.3.7.1.13 Method 13: Synthesis from Methyl(dimethylamino)sulfoxonium Methylide and Acyl Chlorides 380
32.3.7.1.14 Method 14: Synthesis from Allenyl Sulfones 381
32.3.7.1.15 Method 15: Synthesis from a-Diazo Ketones 381
32.3.7.1.16 Method 16: Synthesis from a-(Dioxidosulfanylidene) Ketones 381
32.3.7.1.17 Method 17: Synthesis of 2,3-Dihydro-1,4-oxathiin 382
32.3.7.1.18 Method 18: Synthesis by Thio- and Seleno-Lactonizations of Alkynoic Acids 382
32.3.7.1.19 Method 19: Synthesis from (Phenyltellanyl)acetaldehyde Diethyl Acetal 382
32.3.8 Product Subclass 8: 1-Nitrogen-Functionalized 2-(Organooxy)alkenes 386
32.3.8.1 Synthesis of Product Subclass 8 386
32.3.8.1.1 Method 1: Synthesis by Substitution of Diazonium Salts 386
32.3.8.1.2 Method 2: Synthesis by Reduction of Arenes 386
32.3.8.1.3 Method 3: Synthesis by Amino Enolate Alkylation 386
32.3.8.1.4 Method 4: Synthesis by C--O Bond Formation 387
32.3.8.1.5 Method 5: Synthesis by Rearrangement 388
32.3.8.1.6 Method 6: Synthesis by Ring Opening of Oxazoles 388
32.3.8.1.7 Method 7: Synthesis of Oxazol-2(3H)-ones 388
32.3.8.1.7.1 Variation 1: Synthesis from a-Amino Ketones 389
32.3.8.1.7.2 Variation 2: Synthesis from a-Hydroxy Ketones 389
32.3.8.1.7.3 Variation 3: Synthesis from 2-Oxoalkyl Dialkylcarbamates 389
32.3.8.1.7.4 Variation 4: Synthesis by Intramolecular Cyclization 389
32.3.8.1.7.5 Variation 5: Synthesis by Elimination of Hydrogen Chloride 390
32.3.8.1.7.6 Variation 6: Synthesis by Elimination of Diphenylphosphine Oxide 390
32.3.8.1.7.7 Variation 7: Synthesis by Curtius Rearrangement 391
32.3.8.1.7.8 Variation 8: Synthesis from 2-(Allyloxy)oxazoles 391
32.3.8.1.8 Method 8: Synthesis from Oximes 392
32.3.8.1.9 Method 9: Synthesis by Intramolecular Cyclization 392
32.3.8.1.10 Method 10: Synthesis by Elimination 393
32.3.8.1.11 Method 11: Synthesis of 3-Hydroxypyridin-4(1H)-ones 393
32.3.8.1.12 Method 12: Synthesis from tert-Butyl Isocyanide 394
32.3.9 Product Subclass 9: 1-Phosphorus-Functionalized 2-(Organooxy)alkenes 396
32.3.9.1 Synthesis of Product Subclass 9 396
32.3.9.1.1 Method 1: Phosphorylation of Alkynyl Ethers 396
32.3.9.1.2 Method 2: Phosphorylation of Vinyl Ethers 396
32.3.9.1.3 Method 3: Synthesis by O-Alkylation of a-Oxo Ylides 396
32.3.9.1.4 Method 4: O-Phosphorylation of an a-Oxo Ylide 
397 
32.3.9.1.5 Method 5: Cleavage of Cyclic Phosphonium Salts 397
32.3.9.1.6 Method 6: Synthesis from Enol Ethers 397
32.3.9.1.7 Method 7: Synthesis from 1,2-Bis(triorganophosphonio)ethene Dihalides 398
32.3.9.1.8 Method 8: Synthesis from Alkynyl Ethers 398
32.3.9.1.8.1 Variation 1: Addition of Alkyl- or Aryldichlorophosphines 398
32.3.9.1.8.2 Variation 2: Addition of Trihalophosphines 398
32.3.10 Product Subclass 10: 1,2-Bis(sulfur-functionalized) Alkenes 400
32.3.10.1 Synthesis of Product Subclass 10 400
32.3.10.1.1 Method 1: Synthesis from Vinyl Sulfides 400
32.3.10.1.2 Method 2: Synthesis by Reduction 400
32.3.10.1.3 Method 3: Synthesis by Substitution of Ammonium Salts 400
32.3.10.1.4 Method 4: Synthesis by Substitution of a Halogen 401
32.3.10.1.5 Method 5: Synthesis from 3-Oxotetrahydrothiophene-2-carboxylates 401
32.3.10.1.6 Method 6: Synthesis from Cyclopropanes 402
32.3.10.1.7 Method 7: Synthesis from Cyclopropenes 402
32.3.10.1.8 Method 8: Synthesis by Elimination of Hydrogen Bromide 402
32.3.10.1.9 Method 9: Synthesis by Elimination of Water 403
32.3.10.1.10 Method 10: Synthesis by Elimination of Thiols 403
32.3.10.1.11 Method 11: Synthesis by Addition to Allenes 404
32.3.10.1.12 Method 12: Synthesis by Addition to Alkynes 405
32.3.10.1.13 Method 13: Synthesis from Alkynes and Carbon Disulfide 406
32.3.10.1.14 Method 14: Synthesis by Carbene Dimerization 407
32.3.10.1.15 Method 15: Synthesis by Double-Bond Migration 408
32.3.10.1.16 Method 16: Synthesis by Rearrangement of 1,3-Dithiolane 1-Oxides 408
32.3.10.1.17 Method 17: Synthesis by Rearrangement of 1,1-Bis(sulfonyl)ethenes 408
32.3.10.1.18 Method 18: Synthesis from Dithiins 409
32.3.10.1.19 Method 19: Synthesis with Retention of the Functional Group 412
32.3.10.1.19.1 Variation 1: S-Alkylation 412
32.3.10.1.19.2 Variation 2: Synthesis by Chain Elongation 412
32.3.10.1.19.3 Variation 3: Ring Enlargement of Dithioles 413
32.3.10.1.19.4 Variation 4: Nucleophilic Addition to Dithiolium Salts 413
32.3.11 Product Subclass 11: 1-Sulfur-Functionalized 2-(Organochalcogeno)alkenes 416
32.3.11.1 Synthesis of Product Subclass 11 416
32.3.11.1.1 Method 1: Addition to Alkynyl Sulfones 416
32.3.11.1.2 Method 2: Selenosulfonylation of Alkynes 417
32.3.11.1.3 Method 3: Synthesis of Cyclic 1-Sulfanyl-2-tellanylethenes 418
32.3.12 Product Subclass 12: 1-Sulfur-Functionalized 2-Nitrogen-Functionalized Alkenes 420
32.3.12.1 Synthesis of Product Subclass 12 420
32.3.12.1.1 Method 1: Synthesis from Enamines 420
32.3.12.1.2 Method 2: Synthesis from Vinyl Azides 422
32.3.12.1.3 Method 3: Synthesis from Imines and Derivatives 422
32.3.12.1.4 Method 4: Synthesis from ß-Oxo Sulfones and Amines 423
32.3.12.1.5 Method 5: Synthesis by Substitution from Heteroatom-Substituted Alkenes 423
32.3.12.1.6 Method 6: Synthesis from Aldehydes and Tosylmethyl Isocyanide 425
32.3.12.1.7 Method 7: Synthesis from Ylides and Thiocyanogen 426
32.3.12.1.8 Method 8: Synthesis by Elimination of Hydrogen Chloride 426
32.3.12.1.9 Method 9: Synthesis by Elimination of Ethanethiol 426
32.3.12.1.10 Method 10: Synthesis by Aminomercuration of Alkynes 427
32.3.12.1.11 Method 11: Synthesis by Addition of Aziridines to Alk-1-ynyl Sulfoxides, Allenyl Sulfoxides, or Allenyl Sulfones 427
32.3.12.1.12 Method 12: Synthesis by Ring Opening of Azirines 428
32.3.12.1.13 Method 13: Synthesis from Sulfur Ylides and Nitriles 428
32.3.12.1.14 Method 14: Synthesis by Cycloaddition of a-Imino Thiones 429
32.3.12.1.15 Method 15: Synthesis by Rearrangement of Thietanes 429
32.3.12.1.16 Method 16: Synthesis by S-Oxidation 429
32.3.12.1.17 Method 17: Synthesis from Thiazolium Salts and Nucleophiles or Electrophiles 430
32.3.12.1.18 Method 18: Synthesis from Thiazines 431
32.3.12.1.19 Method 19: Synthesis by C-Imidoylation of Sulfoxides 431
32.3.13 Product Subclass 13: 1-Sulfur-Functionalized 2-Phosphorus-Functionalized Alkenes 434
32.3.13.1 Synthesis of Product Subclass 13 434
32.3.13.1.1 Method 1: Synthesis by Substitution 434
32.3.13.1.1.1 Variation 1: Of Chloroalkenes 434
32.3.13.1.1.2 Variation 2: Of Vinyl Sulfones 434
32.3.13.1.1.3 Variation 3: Of Vinylphosphonium Salts 434
32.3.13.1.2 Method 2: Synthesis by Elimination 435
32.3.13.1.3 Method 3: Synthesis by Addition to Alkynes, Alkenes, or Allenes 435
32.3.13.1.4 Method 4: Synthesis by Cycloaddition 436
32.3.13.1.5 Method 5: Synthesis by Isomerization 437
32.3.13.1.6 Methods 6: Other Methods 437
32.3.14 Product Subclass 14: 1,2-Bis(nitrogen-functionalized) Alkenes 440
32.3.14.1 Synthesis of Product Subclass 14 440
32.3.14.1.1 Method 1: Synthesis of 1,2-Dinitroalkenes 440
32.3.14.1.2 Method 2: Synthesis of 1-Amino-2-nitroalkenes 440
32.3.14.1.2.1 Variation 1: Synthesis from Ortho Esters and Nitroalkanes 440
32.3.14.1.2.2 Variation 2: Synthesis from Imines 441
32.3.14.1.2.3 Variation 3: Synthesis from Carboxylic Acid Derivatives 441
32.3.14.1.2.4 Variation 4: Synthesis from 4-Nitrocyclobut-1-en-1-amines 442
32.3.14.1.2.5 Variation 5: Synthesis from Haloalkenes 442
32.3.14.1.2.6 Variation 6: Synthesis by Rearrangement 442
32.3.14.1.3 Method 3: Synthesis of 4-Nitro-1,2-dihydro-3H-pyrazol-3-ones 443
32.3.14.1.4 Method 4: Synthesis of 1,2-Bis(diazenyl)alkenes 443
32.3.14.1.5 Method 5: Synthesis of 1-Amino-2-diazenylalkenes 444
32.3.14.1.6 Method 6: Synthesis of Alkene-1,2-diamines 444
32.3.14.1.6.1 Variation 1: Synthesis from 1-Alkoxymethanediamines 444
32.3.14.1.6.2 Variation 2: Synthesis by Amine Elimination 445
32.3.14.1.6.3 Variation 3: Synthesis from a-Halo or a-Dialkylamino Aldehydes 445
32.3.14.1.6.4 Variation 4: Synthesis from 1-Amino-2-haloalkenes 445
32.3.14.1.6.5 Variation 5: Synthesis from 1,2-Diols 446
32.3.14.1.6.6 Variation 6: Synthesis from Cyclopropenium Ion Derivatives 446
32.3.14.1.7 Method 7: Synthesis of Dihydroimidazoles 447
32.3.14.1.8 Method 8: Synthesis of 1,4-Dihydropyrazines 449
32.3.14.1.9 Method 9: Synthesis of Tetrahydropyrazines 449
32.3.14.1.10 Method 10: Synthesis of 4,5,6,7-Tetrahydro-1H-1,4-diazepines 451
32.3.14.1.11 Method 11: Synthesis of 1,2,4-Triazines 451
32.3.14.1.12 Method 12: Synthesis of 1,2-Diazidoalkenes 452
32.3.15 Product Subclass 15: 1-Nitrogen-Functionalized 2-Phosphorus-Functionalized Alkenes 456
32.3.15.1 Synthesis of Product Subclass 15 456
32.3.15.1.1 Method 1: Synthesis by Substitution 456
32.3.15.1.1.1 Variation 1: Substitution of Chloroalkenes 456
32.3.15.1.1.2 Variation 2: Substitution of Bromoalkenes 456
32.3.15.1.1.3 Variation 3: Substitution of Alkylphosphonium Salts 456
32.3.15.1.2 Method 2: Synthesis from Phosphorus Ylides 456
32.3.15.1.3 Method 3: Condensation of ß-Oxo Phosphonium Salts with Amines 457
32.3.15.1.4 Method 4: Synthesis by Addition to Phosphorus-Functionalized Alkynes 457
32.3.15.1.5 Method 5: Synthesis of 1-(Isothiocyanato/isocyanato)-2-(difluorophosphoryl)alkenes 459
32.3.16 Product Subclass 16: 1,2-Bis(phosphorus-functionalized) Alkenes 462
32.3.16.1 Synthesis of Product Subclass 16 462
32.3.16.1.1 Method 1: Substitution of Chloroalkenes 462
32.3.16.1.2 Method 2: Synthesis from Acyl Halides 462
32.3.16.1.3 Method 3: Addition to Alkynes 462
32.3.16.1.4 Method 4: Synthesis from 2,3-Dihydro-1H-1,3,2-diphosphasiloles 464
32.4 Product Class 4: Haloalkenes 466
32.4.1 Product Subclass 1: Fluoroalkenes 466
32.4.1.1 Synthesis of Product Subclass 1 467
32.4.1.1.1 Synthesis from Organometallic Compounds 467
32.4.1.1.1.1 Method 1: Synthesis from Vinylstannanes 468
32.4.1.1.1.1.1 Variation 1: Fluorodestannylation with Xenon Difluoride 468
32.4.1.1.1.1.2 Variation 2: Fluorodestannylation with Cesium Fluoroxysulfate 470
32.4.1.1.1.1.3 Variation 3: Fluorodestannylation with Selectfluor 470
32.4.1.1.1.2 Method 2: Synthesis from Vinylborates 470
32.4.1.1.1.3 Method 3: Synthesis from Vinyllithiums 471
32.4.1.1.2 Synthesis from Alkanes 471
32.4.1.1.2.1 Method 1: Dehydrohalogenation 472
32.4.1.1.2.1.1 Variation 1: Dehydrofluorination 472
32.4.1.1.2.1.2 Variation 2: Dehydrohalogenation 474
32.4.1.1.2.2 Method 2: Reductive Dehalogenation Using Reducing Metals or Hydrogen 474
32.4.1.1.2.3 Method 3: Dehalogenation with Phosphites and Phosphines 477
32.4.1.1.2.4 Method 4: Thermal syn Elimination 477
32.4.1.1.3 Synthesis from Alkenes 478
32.4.1.1.3.1 Method 1: Addition/Elimination Reactions 478
32.4.1.1.3.1.1 Variation 1: Using N-Fluorobis(trifluoromethane)sulfonimide 478
32.4.1.1.3.1.2 Variation 2: Using Trifluoromethyl Hypofluorite 478
32.4.1.1.3.1.3 Variation 3: Using Acetyl Hypofluoride 479
32.4.1.1.3.2 Method 2: Dihalocarbene Addition and Subsequent Ring Opening 479
32.4.1.1.3.2.1 Variation 1: Formation of a-Fluoro a,ß-Unsaturated Carbonyl Compounds or Acetals 
479 
32.4.1.1.3.2.2 Variation 2: Formation of Simple Fluoroalkenes 480
32.4.1.1.3.2.3 Variation 3: Formation of Conjugated Fluorodienes 481
32.4.1.1.4 Synthesis from Aldehydes and Ketones 482
32.4.1.1.4.1 Method 1: Alkenation Reactions 482
32.4.1.1.4.1.1 Variation 1: Wittig Alkenation 482
32.4.1.1.4.1.2 Variation 2: Horner--Wadsworth--Emmons Alkenation 483
32.4.1.1.4.1.3 Variation 3: Julia Alkenation 484
32.4.1.1.4.1.4 Variation 4: Miscellaneous Alkenations 485
32.4.1.1.4.2 Method 2: Substitution of Oxygen in Carbonyl Compounds 485
32.4.1.1.5 Synthesis from Carboxylic Acids and Their Derivatives 485
32.4.1.1.5.1 Method 1: Wittig Alkenation 486
32.4.1.1.5.2 Method 2: Horner--Wadsworth--Emmons Alkenation 486
32.4.1.1.6 Synthesis from Alkynes and Allenes 487
32.4.1.1.6.1 Method 1: Addition of Hydrogen Fluoride to Alkynes 487
32.4.1.1.6.2 Method 2: Addition of Halogen Fluorides to Alkynes 488
32.4.1.1.6.3 Method 3: Formal Addition of Benzenesulfenyl Fluoride to Alkynes 489
32.4.1.1.6.4 Method 4: Formal Addition of Benzeneselenenyl Fluoride to Alkynes 489
32.4.1.1.6.5 Method 5: Addition to Allenes 490
32.4.1.1.7 Modifications of Compounds Already Containing a Fluorovinyl Substituent 490
32.4.1.1.7.1 Method 1: Cross-Coupling Reactions 491
32.4.1.1.7.1.1 Variation 1: Suzuki--Miyaura Cross Coupling 491
32.4.1.1.7.1.2 Variation 2: Stille Cross Coupling 491
32.4.1.1.7.1.3 Variation 3: Negishi Cross Coupling 493
32.4.1.1.7.1.4 Variation 4: Sonogashira Cross Coupling 494
32.4.1.1.7.2 Method 2: Functional-Group Exchange 494
32.4.1.1.7.2.1 Variation 1: Dehalogenation 494
32.4.1.1.7.2.2 Variation 2: Hydrodefluorination with Trialkylphosphines 495
32.4.1.1.7.2.3 Variation 3: Iododefluorination with Trialkylphosphines 495
32.4.1.1.7.2.4 Variation 4: Hydrodestannylation 495
32.4.1.1.7.3 Method 3: Allylic Substitution with N,N-Diethylaminosulfur Trifluoride 496
32.4.1.1.7.4 Method 4: Isomerization 496
32.4.1.1.7.5 Method 5: Rearrangement 496
32.4.2 Product Subclass 2: Chloro-, Bromo-, and Iodoalkenes 497
32.4.2.1 Synthesis of Product Subclass 2 498
32.4.2.1.1 Synthesis from Organometallic Compounds 498
32.4.2.1.1.1 Method 1: Synthesis from Vinylstannanes 499
32.4.2.1.1.2 Method 2: Stepwise Replacement of Zirconium or Tin 502
32.4.2.1.1.3 Method 3: Synthesis from Vinylsilanes 503
32.4.2.1.1.4 Method 4: Synthesis from Vinylaluminum Compounds 505
32.4.2.1.1.5 Method 5: Synthesis from Vinylborates 506
32.4.2.1.1.6 Method 6: Synthesis from Vinylzirconium Compounds 508
32.4.2.1.1.7 Method 7: Synthesis from Vinylmagnesium Compounds 509
32.4.2.1.2 Synthesis from Alkanes 510
32.4.2.1.2.1 Method 1: Dehydrohalogenation 510
32.4.2.1.2.1.1 Variation 1: Under Basic Conditions 510
32.4.2.1.2.1.2 Variation 2: Under Thermal Conditions 512
32.4.2.1.2.2 Method 2: Electroreduction 512
32.4.2.1.2.3 Method 3: Dehalogenation with Reducing Metals 513
32.4.2.1.2.4 Method 4: Dehalogenation with Phosphites and Phosphines 514
32.4.2.1.2.5 Method 5: Thermal syn Elimination 514
32.4.2.1.3 Synthesis from Alkenes 515
32.4.2.1.3.1 Method 1: C-Halogenation 515
32.4.2.1.3.2 Method 2: Dihalocarbene Addition and Subsequent Ring Opening 515
32.4.2.1.3.2.1 Variation 1: Formation of Haloalkenes 515
32.4.2.1.3.2.2 Variation 2: Formation of a-Halo a,ß-Unsaturated Carbonyl Compounds 516
32.4.2.1.3.2.3 Variation 3: Formation of Conjugated Halodienes 517
32.4.2.1.4 Synthesis from Halocarbenes 517
32.4.2.1.5 Synthesis from Aldehydes and Ketones 518
32.4.2.1.5.1 Method 1: Wittig Alkenation 518
32.4.2.1.5.1.1 Variation 1: Formation of Chloroalkenes 518
32.4.2.1.5.1.2 Variation 2: Formation of Bromoalkenes 518
32.4.2.1.5.1.3 Variation 3: Formation of Iodoalkenes 520
32.4.2.1.5.1.4 Variation 4: Formation of a-Halo a,ß-Unsaturated Esters 521
32.4.2.1.5.2 Method 2: Horner--Wadsworth--Emmons Alkenation 521
32.4.2.1.5.3 Method 3: Takai Alkenation 523
32.4.2.1.5.4 Method 4: Halo-Julia Alkenation 525
32.4.2.1.5.5 Method 5: Chromium(II)- and Iron(0)-Mediated Alkenation 525
32.4.2.1.5.6 Method 6: Morita--Baylis--Hillmann Addition 526
32.4.2.1.5.7 Method 7: Vilsmeier Haloformylation 526
32.4.2.1.5.8 Method 8: Substitution of Oxygen in Carbonyl Compounds 527
32.4.2.1.5.8.1 Variation 1: Using Phosphorus Pentachloride 527
32.4.2.1.5.8.2 Variation 2: Via Vinyl Trifluoromethanesulfonates 527
32.4.2.1.5.8.3 Variation 3: Via Vinyl Phosphates 528
32.4.2.1.5.8.4 Variation 4: Reaction of Enolizable Aldehydes with 2-Chlorobenzoxazolium Salts 528
32.4.2.1.5.9 Method 9: Allylborination 529
32.4.2.1.6 Synthesis from Carboxylic Acids and Derivatives 529
32.4.2.1.6.1 Method 1: The Hunsdiecker Reaction 529
32.4.2.1.6.2 Method 2: Wittig Alkenation 530
32.4.2.1.7 Synthesis from Alkynes and Allenes 530
32.4.2.1.7.1 Method 1: Hydrohalogenation of Alkynes 531
32.4.2.1.7.1.1 Variation 1: Addition of Halogen Acids 531
32.4.2.1.7.1.2 Variation 2: Hydrohalogenation with Alkali Metal Halides 531
32.4.2.1.7.2 Method 2: Halogenation of Alkynes 533
32.4.2.1.7.3 Method 3: Addition of a Halogen and a Heteroatom 535
32.4.2.1.7.3.1 Variation 1: Addition of Halogen and Nitrogen 535
32.4.2.1.7.3.2 Variation 2: Addition of Halogen and Oxygen 535
32.4.2.1.7.3.3 Variation 3: Addition of Halogen and Sulfur or Selenium 536
32.4.2.1.7.4 Method 4: Transformations of Haloalkynes 536
32.4.2.1.7.4.1 Variation 1: Using Boranes 536
32.4.2.1.7.4.2 Variation 2: Using Lithium Aluminum Hydride 537
32.4.2.1.7.4.3 Variation 3: Using Diimides 537
32.4.2.1.7.5 Method 5: Alkene--Alkyne Coupling 537
32.4.2.1.7.6 Method 6: Iodocyclization of Alkynes 539
32.4.2.1.7.7 Method 7: Hydrohalogenation of Allenes 539
32.4.2.1.7.8 Method 8: Halogenation of Allenes 540
32.4.2.1.7.9 Method 9: Addition of Halogen and Oxygen to Allenes 540
32.4.2.1.7.9.1 Variation 1: Halohydroxylation 540
32.4.2.1.7.9.2 Variation 2: Haloacetylation 541
32.4.2.1.7.10 Method 10: SN2' Reactions of Allenols 
541 
32.4.2.1.8 Modification of Compounds Already Containing a Halogenated Alkenyl Function 542
32.4.2.1.8.1 Method 1: Cross-Coupling Reactions 542
32.4.2.1.8.1.1 Variation 1: Suzuki--Miyaura Cross Coupling 542
32.4.2.1.8.1.2 Variation 2: Stille Cross Coupling 544
32.4.2.1.8.1.3 Variation 3: Negishi Cross Coupling 546
32.4.2.1.8.1.4 Variation 4: Sonogashira Cross Coupling 547
32.4.2.1.8.1.5 Variation 5: Kumada Cross Coupling 547
32.4.2.1.8.2 Method 2: Carbonyl Addition of Vinyllithium Reagents 548
32.4.2.1.8.3 Method 3: Substitution of Halogens by Other Nucleophiles 549
32.4.2.1.8.4 Method 4: Halodemetalation 550
32.4.2.1.8.4.1 Variation 1: Halodestannylation or Halodeboration 550
32.4.2.1.8.5 Method 5: Dehalogenation 551
32.4.2.1.8.5.1 Variation 1: Using Lithium Aluminum Hydride 551
32.4.2.1.8.5.2 Variation 2: Using Reducing Metals 551
32.4.2.1.8.5.3 Variation 3: Via Stannanes 552
32.4.2.1.8.5.4 Variation 4: Using Organolithiums 552
32.4.2.1.8.5.5 Variation 5: Using Diethyl Phosphonates 553
32.4.2.1.8.6 Method 6: Ring Opening of 1,2-Dihalocyclopropenes 553
32.5 Product Class 5: (Organooxy)alkenes 568
32.5.1 Product Subclass 1: Enols 568
32.5.1.1 Synthesis of Product Subclass 1 570
32.5.1.1.1 Method 1: Equilibration from the Corresponding Carbonyl Form 570
32.5.1.1.2 Method 2: Transition-Metal-Catalyzed Isomerization of Allylic Alcohols 571
32.5.1.1.3 Method 3: Photochemical Cleavage 571
32.5.1.1.4 Method 4: Mild Hydrolysis of Enol Ketene Acetals or Enol Ortho Esters 571
32.5.1.1.5 Method 5: Sigmatropic Rearrangements 572
32.5.1.2 Applications of Product Subclass 1 in Organic Synthesis 572
32.5.1.2.1 Method 1: Deprotonation and Subsequent Reaction as an Enolate 572
32.5.1.2.2 Method 2: O-Alkylation and O-Silylation under Neutral Conditions 573
32.5.1.2.3 Method 3: Hydrogenation 574
32.5.1.2.4 Method 4: Reaction with Carbon Electrophiles under Neutral or Acidic Conditions 575
32.5.1.2.5 Method 5: Reaction with Nitrogen Electrophiles 576
32.5.1.2.6 Method 6: Reaction with Oxygen Electrophiles 576
32.5.1.2.7 Method 7: Reaction with Sulfur and Selenium Electrophiles 577
32.5.1.2.8 Method 8: Reaction with Electrophilic Halide Reagents 578
32.5.1.2.9 Method 9: Photochemical Cycloadditions 578
32.5.1.2.10 Method 10: Oxidative Cyclizations 579
32.5.2 Product Subclass 2: Enolates 582
32.5.2.1 Synthesis of Product Subclass 2 583
32.5.2.1.1 Method 1: Synthesis by Deprotonation 584
32.5.2.1.1.1 Variation 1: Kinetic Deprotonation of a Ketone 584
32.5.2.1.1.2 Variation 2: Deprotonation under Thermodynamic Conditions 586
32.5.2.1.1.3 Variation 3: Double Deprotonation of a 1,4-Dicarbonyl Compound 587
32.5.2.1.1.4 Variation 4: Enantioselective Deprotonation of Symmetrical Ketones 588
32.5.2.1.1.5 Variation 5: Deprotonation with Organozinc Compounds 589
32.5.2.1.2 Method 2: Synthesis by Cleavage of Enol Esters and Ethers 590
32.5.2.1.2.1 Variation 1: Cleavage of Enol Esters 591
32.5.2.1.2.2 Variation 2: Cleavage of Enol Ethers 591
32.5.2.1.2.3 Variation 3: Cleavage of Silyl Enol Ethers 591
32.5.2.1.3 Method 3: Synthesis by Reduction of a-Halocarbonyl and Related Compounds 
592 
32.5.2.1.4 Method 4: Synthesis by Conjugate Reduction 593
32.5.2.1.5 Method 5: Synthesis by Conjugate Addition 595
32.5.2.1.6 Method 6: Synthesis by Nucleophilic Addition to Ketenes 596
32.5.2.1.7 Method 7: Synthesis by Base-Induced Rearrangement of Epoxides 597
32.5.2.1.8 Method 8: Synthesis by Anionic Oxy-Cope Rearrangement 598
32.5.2.1.9 Method 9: Synthesis by Rearrangement of Allylic Alkoxides 600
32.5.2.2 Applications of Product Subclass 2 in Organic Synthesis 600
32.5.2.2.1 Method 1: Transmetalation To Form Transition Metal Enolates and Zinc Enolates 601
32.5.2.2.1.1 Variation 1: Transmetalation with Organotitanium or Organozirconium Complexes 601
32.5.2.2.1.2 Variation 2: Transmetalation with Nickel(II) or Palladium(II) Complexes 602
32.5.2.2.1.3 Variation 3: Transmetalation with Magnesium, Titanium, Manganese, or Zinc Salts 604
32.5.2.2.2 Method 2: Formation of Boron Enolates 604
32.5.2.2.3 Method 3: O-Alkylation and O-Acylation To Form Enol Ethers and Enol Esters 605
32.5.2.2.4 Method 4: Formation of Silyl Enol Ethers and Tin Enolates 606
32.5.2.2.5 Method 5: Reaction with S-Electrophiles: Formation of Enol Trifluoromethanesulfonates 607
32.5.2.2.6 Method 6: Protonation and Deuteration of Enolates 608
32.5.2.2.7 Method 7: Reaction on the C-Terminus with C-Electrophiles 610
32.5.2.2.7.1 Variation 1: Alkylation 610
32.5.2.2.7.2 Variation 2: Aldol Addition 612
32.5.2.2.7.3 Variation 3: Acylation (Claisen Condensation) 614
32.5.2.2.8 Method 8: Reaction of Enolates on the C-Terminus with Electrophilic Heteroatom Species 615
32.5.2.2.8.1 Variation 1: Reaction with Electrophilic Nitrogen Species 615
32.5.2.2.8.2 Variation 2: Reaction with Electrophilic Oxygen Species 616
32.5.2.2.8.3 Variation 3: Reaction with Electrophilic Sulfur and Selenium Species 617
32.5.2.2.8.4 Variation 4: Reaction with Electrophilic Halogen Species 618
32.5.2.2.9 Method 9: Oxidative Dimerization of Enolates and Related Oxidative Couplings 619
32.5.3 Product Subclass 3: Enol Ethers 624
32.5.3.1 Synthesis of Product Subclass 3 625
32.5.3.1.1 Formation of an O--R1 Bond (Alkylation of the Oxygen Atom) 625
32.5.3.1.1.1 Method 1: Alkylation of Carbonyl Compounds 625
32.5.3.1.1.1.1 Variation 1: Reactions of Enolates with Alkylating Agents 626
32.5.3.1.1.1.2 Variation 2: Reactions of Enolates with Diazoalkanes 627
32.5.3.1.1.1.3 Variation 3: Reaction of Ketones with Ethyl Diazoacetate 627
32.5.3.1.1.2 Method 2: Alkylation of Silyl Ethers 628
32.5.3.1.2 Formation of the a-C--O Bond 629
32.5.3.1.2.1 Method 1: Reaction of Vinyl Halides or Activated Vinyl Derivatives with Alcohols or Phenols 630
32.5.3.1.2.1.1 Variation 1: Nucleophilic Displacement 630
32.5.3.1.2.1.2 Variation 2: Copper-Catalyzed C--O Bond-Forming Reactions 633
32.5.3.1.2.1.3 Variation 3: Palladium-Catalyzed C--O Bond-Forming Reactions 637
32.5.3.1.2.1.4 Variation 4: Reaction of Perfluorovinyl Fluorides with Alcohols or Phenols 639
32.5.3.1.2.2 Method 2: Addition to Alkynes 640
32.5.3.1.2.2.1 Variation 1: Addition of Alcohols to Alkynes 640
32.5.3.1.2.2.2 Variation 2: cis Addition of Alcohols to Alkynones and Alkynoic Acid Derivatives 642
32.5.3.1.2.2.3 Variation 3: trans Addition of Alcohols to Alkynones and Alkynoic Acid Derivatives 643
32.5.3.1.2.2.4 Variation 4: Addition of Carbonyl Compounds to Alkynones and Alkynoic Acid Derivatives 645
32.5.3.1.2.2.5 Variation 5: Addition to Alkynes with Formation of Cyclic Enol Ethers 647
32.5.3.1.2.3 Method 3: Addition to Allenes or Methylenecyclopropanes 648
32.5.3.1.2.3.1 Variation 1: Addition to Sulfonyl-Stabilized Allenes 649
32.5.3.1.2.3.2 Variation 2: Reactions Involving Phosphorus-Based Anion-Stabilizing Groups 650
32.5.3.1.2.3.3 Variation 3: Photochemically Induced Reactions of Allenes Involving the Addition of an Alcohol 652
32.5.3.1.2.3.4 Variation 4: Palladium-Catalyzed Cascade Reaction of 4-(Alkoxycarbonyloxy)but-2-yn-1-ols with Phenols 653
32.5.3.1.2.3.5 Variation 5: Addition of Methanol to a Methylenecyclopropane System 654
32.5.3.1.2.4 Method 4: Alkoxide-Mediated Ring-Opening Reactions 655
32.5.3.1.2.4.1 Variation 1: Ring Opening of 1-Phenylthiophenium Salts 655
32.5.3.1.2.4.2 Variation 2: Ring Opening of Isothiazole 1,1-Dioxides 656
32.5.3.1.2.5 Method 5: Transetherification of Vinyl Ethers 657
32.5.3.1.2.5.1 Variation 1: Catalysis with Mercury(II) Salts 657
32.5.3.1.2.5.2 Variation 2: Catalysis with Palladium Compounds 660
32.5.3.1.2.6 Method 6: Transfer of a Vinyl Group from a Vinyl Ester 665
32.5.3.1.3 Substitution at the a-Carbon Atom 666
32.5.3.1.3.1 Method 1: The Heck Reaction 666
32.5.3.1.3.2 Method 2: Transition-Metal-Mediated Cross-Coupling Reactions 670
32.5.3.1.3.2.1 Variation 1: The Stille Reaction 670
32.5.3.1.3.2.2 Variation 2: Suzuki and Negishi Coupling Reactions 673
32.5.3.1.3.2.3 Variation 3: Sonogashira Coupling 678
32.5.3.1.3.3 Method 3: Treatment of a-Metalated Vinyl Ethers with Electrophiles 679
32.5.3.1.3.4 Methods 4: Other Methods 682
32.5.3.1.4 Formation of the C==C Bond by Condensation Reactions 683
32.5.3.1.4.1 Method 1: Condensation of Aldehydes, Ketones, or Ortho Esters with Acidic Methylene Derivatives 683
32.5.3.1.4.1.1 Variation 1: Condensation Reactions of Aldehydes or Ketones with Acidic Methylene Derivatives 683
32.5.3.1.4.1.2 Variation 2: Condensation Reactions of Esters or Ortho Esters with Acidic Methylene Derivatives 684
32.5.3.1.4.1.3 Variation 3: Condensation Reactions of Silyl Ethers with Acidic Methylene Derivatives (Peterson Alkenation) 687
32.5.3.1.4.2 Method 2: Condensation of Carbonyl Compounds with Organophosphorus Reagents 688
32.5.3.1.4.2.1 Variation 1: Condensation of Esters with Organophosphorus Reagents (Wittig-like Reaction) 689
32.5.3.1.4.2.2 Variation 2: Condensation of Aldehydes or Ketones with Organophosphorus Reagents (Wittig Reaction) 692
32.5.3.1.4.2.3 Variation 3: Modifications of the Wittig Reaction 693
32.5.3.1.4.3 Method 3: Reductive Coupling of Ketones with Esters in the Presence of Titanium Complexes (The McMurry Coupling) 696
32.5.3.1.4.4 Method 4: Alkylidenation of Esters with Alkylidene Complexes of Titanium 696
32.5.3.1.4.4.1 Variation 1: With Tebbe's Reagent 696
32.5.3.1.4.4.2 Variation 2: With the Petasis Reagent 700
32.5.3.1.4.4.3 Variation 3: With the Takeda Reagents 705
32.5.3.1.4.4.4 Variation 4: With the Takai Reagent 712
32.5.3.1.4.4.5 Variation 5: With the Grubbs Reagents 714
32.5.3.1.4.5 Method 5: Reaction of Fischer Carbene Complexes with Acetylenes 718
32.5.3.1.5 Formation of the C==C Bond through Elimination 722
32.5.3.1.5.1 Method 1: Elimination of Alcohols from Acetals 722
32.5.3.1.5.1.1 Variation 1: Acid-Catalyzed Eliminations 722
32.5.3.1.5.1.2 Variation 2: Eliminations Using Combinations of Bases and Silyl Halides or Silyl Trifluoromethanesulfonates 723
32.5.3.1.5.1.3 Variation 3: Base-Catalyzed Elimination Reactions 728
32.5.3.1.5.1.4 Variation 4: Titanium(IV) Chloride Promoted Formation of Enol Ethers 729
32.5.3.1.5.1.5 Variations 5: Miscellaneous Alcohol Elimination Reactions 730
32.5.3.1.5.2 Method 2: Elimination of Hydrogen Halides from Halo Ethers 731
32.5.3.1.5.3 Method 3: Elimination Reactions of Sulfoxides, Sulfones, or Selenoxides 735
32.5.3.1.5.4 Method 4: Dehydration of a-Alkoxy ß-Hydroxy Esters 737
32.5.3.1.5.5 Method 5: Elimination of Nitrogen from 3-Alkoxydihydropyrazoles 738
32.5.3.1.5.6 Methods 6: Miscellaneous Elimination Reactions 739
32.5.3.1.6 Formation of the C==C Bond through Isomerization 740
32.5.3.1.6.1 Method 1: Base-Induced Isomerization 740
32.5.3.1.6.2 Method 2: Isomerizations Involving Metalated Carbanionic Intermediates 741
32.5.3.1.6.3 Method 3: Metal-Complex-Catalyzed Isomerizations 742
32.5.3.1.6.3.1 Variation 1: Using Rhodium and Palladium Complexes 742
32.5.3.1.6.3.2 Variation 2: Using Iron Complexes 743
32.5.3.1.6.4 Method 4: Ring-Closing Metathesis Followed by Isomerization 744
32.5.3.1.6.4.1 Variation 1: Activation of the Ring-Closing-Metathesis Catalyst by Hydrogen 744
32.5.3.1.6.4.2 Variation 2: Activation of the Ring-Closing-Metathesis Catalyst by Addition of Inorganic Hydrides 745
32.5.3.1.6.4.3 Variation 3: Activation of the Ring-Closing-Metathesis Catalyst by Addition of Ethyl Vinyl Ether 746
32.5.3.1.6.5 Method 5: Oxidative Isomerizations 747
32.5.3.1.7 Formation of the C==C Bond by Reduction 748
32.5.3.1.7.1 Method 1: Partial Reduction of Phenyl Ethers 748
32.5.3.1.7.2 Method 2: Reduction of Alkynyl Ethers 748
32.5.3.1.8 Substitution of the ß-Carbon 752
32.5.3.1.8.1 Method 1: Palladium-Catalyzed Coupling Reactions 752
32.5.3.1.8.1.1 Variation 1: Heck Arylations 752
32.5.3.1.8.1.2 Variation 2: Stille Coupling Reactions 756
32.5.3.1.8.1.3 Variation 3: Suzuki and Negishi Couplings 756
32.5.3.1.8.1.4 Variation 4: Sonogashira Couplings 759
32.5.3.1.8.1.5 Variation 5: Nazarov Reaction 760
32.5.3.1.8.2 Method 2: Ruthenium-Catalyzed Cross-Enyne Metathesis 763
32.5.3.1.8.3 Method 3: Trifluoroacetylation of Vinyl Ethers 764
32.5.3.1.8.4 Method 4: Friedel--Crafts Reaction of Enol Ethers 764
32.5.3.1.8.5 Method 5: Reaction of ß-Alkenyllithiums with Aldehydes 765
32.5.3.1.9 Rearrangements Leading to Enol Ethers 766
32.5.3.1.9.1 Method 1: [3,3]-Sigmatropic Rearrangements 766
32.5.3.1.9.2 Method 2: Ring-Opening Reactions 766
32.5.3.1.9.3 Method 3: Ring-Expansion Reactions 768
32.5.3.1.10 Concerted Formation of More Than One Bond 770
32.5.3.1.10.1 Method 1: Intermolecular Hetero-Diels--Alder Reactions 770
32.5.3.1.10.1.1 Variation 1: Reaction of Dienophiles with Propenal, Alkylpropenals, or Methyl Vinyl Ketone 770
32.5.3.1.10.1.2 Variation 2: Reaction of Dienophiles with Substituted 2-Oxobut-3-enoic Acid Esters 772
32.5.3.1.10.1.3 Variation 3: Reaction of Dienophiles with 2-Methylene 1,3-Diketones or 2-Benzoacrylonitriles 774
32.5.3.1.10.1.4 Variation 4: Treatment of Dienophiles with Phosphonoheterodienes 776
32.5.3.1.10.1.5 Variation 5: Reaction of Dienophiles with a-Sulfanyl, a-Sulfinyl, or a-Sulfonyl Heterodienes 777
32.5.3.1.10.1.6 Variation 6: Reaction of Dienophiles with a-Trifluoromethyl Heterodienes 
779 
32.5.3.1.10.2 Method 2: Intramolecular Hetero-Diels--Alder Reactions 780
32.5.3.1.11 Miscellaneous Methods 781
32.5.3.1.11.1 Method 1: Retro-Nazarov Reaction 781
32.5.4 Product Subclass 4: Ene--OX Compounds (X = O, S, Se, Te) 792
32.5.4.1 Synthesis of Product Subclass 4 792
32.5.4.1.1 Method 1: Enolate Tosylation 792
32.5.4.1.2 Method 2: Addition to Alkynes 793
32.5.4.1.2.1 Variation 1: Halotosyloxylation of Alkynes 793
32.5.4.1.2.2 Variation 2: Selenotosyloxylation of Alkynes 794
32.5.4.1.3 Method 3: Dehydrofluorination of Polyfluoropropyl 4-Toluenesulfonates 795
32.5.4.1.4 Method 4: Substituent Modification of Polyfluoro-1-(tosyloxy)prop-1-enes 795
32.5.4.1.5 Method 5: Enolate Trifluoromethylsulfonylation by Trifluoromethanesulfonic Anhydride 796
32.5.4.1.6 Method 6: Enolate Trifluoromethylsulfonylation by N-Aryl Trifluoromethanesulfonimides 801
32.5.4.1.7 Method 7: Enolate Trifluoromethylsulfonylation by N-Phenylbis(trifluoromethane)sulfonimide 806
32.5.4.1.8 Method 8: Enolate Perfluoroalkylsulfonylation 809
32.5.4.1.9 Methods 9: Miscellaneous Reactions 812
32.5.5 Product Subclass 5: Ene--ON Compounds 818
32.5.5.1 Synthesis of Product Subclass 5 818
32.5.5.1.1 Method 1: Cycloaddition Reactions 818
32.5.5.1.1.1 Variation 1: 1,3-Dipolar Cycloaddition of Nitrones to Electron-Deficient Allenes 818
32.5.5.1.1.2 Variation 2: Addition of Hydroxylamines to Electron-Deficient Allenes 820
32.5.5.1.1.3 Variation 3: Cycloaddition of Nitrones to Acetylenic Compounds 822
32.5.5.1.1.4 Variation 4: Cyclization of N-Propargylhydroxylamines 824
32.5.5.1.2 Method 2: Addition of Oximes to Acetylene 825
32.5.6 Product Subclass 6: Ene--OP Compounds 830
32.5.6.1 Synthesis of Product Subclass 6 830
32.5.6.1.1 Method 1: Enolate Phosphorylation 830
32.5.6.1.1.1 Variation 1: Synthesis from Aldehydes 830
32.5.6.1.1.2 Variation 2: Synthesis from Ketones 832
32.5.6.1.1.3 Variation 3: Synthesis from Imides 837
32.5.6.1.2 Method 2: Addition of Nucleophilic Reagents to Alkynes 838
32.5.6.1.2.1 Variation 1: Addition to Terminal Alkynes 838
32.5.6.1.2.2 Variation 2: Addition to Internal Alkynes 840
32.5.6.1.3 Method 3: Perkow Reaction 842
32.5.6.1.4 Method 4: Skeleton Modification of P-Oxyalkenes 843
32.5.6.1.4.1 Variation 1: Diels--Alder Reactions 843
32.5.6.1.4.2 Variation 2: [2,3]-Sigmatropic Rearrangements 844
32.5.6.1.5 Methods 5: Miscellaneous Reactions 846
Keyword Index 850
Author Index 902
Abbreviations 944