Rhodium‐ and Palladium‐Catalyzed Asymmetric Conjugate Additions

Abstract

Since the seminal report by Uemura [1] in 1995 for palladium, and by Miyaura in 1997 for rhodium [2], the late transition metal-catalyzed conjugate addition of organoboron reagents to activated alkenes has emerged as one of the most functional group-tolerant and reliable carbon–carbon bond-forming processes. The maturity of this methodology is such that it has become an ideal testing ground for new ligand concepts and design, as will be illustrated throughout this chapter. A true statement to the robustness of this process is the application of Rh-catalyzed enantioselective conjugate addition (ECA) on a kilogram-scale for the manufacture of advanced pharmaceutical ingredients, and its use as a key step in the synthesis of complex natural products [3–5]. In this chapter, an overview will be provided – spanning from 2003 to mid-2009 – of the developments in the field of rhodiumand palladium-catalyzed ECA of organometallic reagents (B, Si, Zn, and Ti) to activated alkenes. The chapter is not intended to be comprehensive, and will include only selected examples of this powerful methodology. For more in-depth and comprehensive accounts, the reader should consult a number of excellent reviews that are available on this subject [6–16].