ABSTRACT

Carbon-carbon bond formation is central to synthetic organic chemistry and the transition metalcatalyzed cross-coupling of aryl/vinyl halides with organometallic reagents has proven to be a highly effective strategy for the construction of C-C bonds.1 Initially, Kochi reported the utility of Fe(III) catalyst2 and Li2CuCl43 for the cross-coupling of Grignard reagents with vinyl halides and alkyl halides, respectively. Later, Kumada and coworkers4 and Corriu and Masse5 observed the reaction of organomagnesium reagents with vinyl/aryl halides catalyzed by Ni(II) complex. The ™rst Pd-catalyzed coupling of Grignard reagents was reported by Murahashi and coworkers.6 The utility of palladium catalysis was further expanded for the coupling of other organometallic reagents by several researchers including Negishi (aluminum,7 zinc,8 zirconium9), Suzuki and coworkers10 (boron), Murahashi et al.11 (lithium), Milstein and Stille12 and Migita and coworkers13 (tin), Alexakis and Normant14 (copper), and Hatanaka and Hiyama15 (silicon). Although most of these methods have  been utilized in a wide variety of applications, the boron-based Suzuki-Miyaura crosscoupling reaction has proven to be the most popular among all these.* This reaction offers distinct advantages over others in terms of optimal reactivity of organoboron compounds as opposed to the highly reactive Grignards or the relatively unreactive copper/silicon reagents). Further bene™ts of this protocol include the use of air-and water-stable, relatively nontoxic, and environmentally benign starting materials and by-products (borates and boric acid as opposed to heavy metals such as tin, etc.).