Organic Reactions

Volume 79 in the venerable Organic Reactions series contains two chapters: the first addresses cross-coupling reactions of organotrifluoroborate salts, useful in the development of natural products, materials, and pharmacologically active substances; the second chapter addresses asymmetric transformations by deprotonation using chiral lithium amides, useful in target-oriented synthesis. The first chapter by Gary A. Molander and Ludivine Jean-Gerard describes the use of organotrifluoroborate salts in a modification of the Nobel Prize winning Suzuki-Miyaura cross-coupling reaction. The impact of this palladium-catalyzed transformation in academic and especially industrial organic synthesis cannot be overestimated. Boronic acid cross-coupling has evolved as the primary strategic disconnection for making carbon-carbon bonds. This excellent chapter on boron-based cross-coupling reactions joins two previous chapters on tin-based (Stille-Kosugi-Migita) and silicon-based (Hiyama-Denmark) cross-couplings contained in Volumes 50 and 75, respectively, to form a triumvirate of the most commonly employed examples of this transformation.The second chapter by Nigel S. Simpkins and Michael D. Weller describes the successful marriage of classic lithium enolate chemistry with the modern concepts and methods of asymmetric synthesis. The formation of lithium enolates by stoichiometric deprotonation with lithium amide bases revolutionized the chemistry of carbonyl compounds by allowing the controlled formation of highly reactive enolates in a site and geometrically defined manner. The subsequent transformations with electrophiles soon evolved into one of the most powerful workhorse reactions in organic synthesis.