The Chemistry of Boron Enolate: Synthesis and Reactivity

Abstract

Fifty years have passed since the first boron enolate appeared in the literature. Important paradigm shifting achievements were frequent in this subject. In the 1970s, Mukaiyama demonstrated the applicability of boron enolates in directed aldol reactions. In the 1980s, Masamune and Evans independently developed highly efficient and practical asymmetric aldol reactions to provide powerful tools in organic synthesis. Significance of these achievements includes the establishment of the new concept of double asymmetric synthesis as a reliable tool for controlling stereochemistry. Since the 1990s, transition metals are introduced to organoboron chemistry, and the scope of the boron enolate chemistry has been expanded. The feasibility of using boron compounds in transition metal chemistry has been widely demonstrated, including in the isolation of C ‐bound boron enolates. The C ‐bound boron enolates, which used to be considered as transient species, are now recognized as important players in the boron enolate chemistry. Advances of the preparation of boron enolates and their applications to organic synthesis are reviewed.