Copper-Catalyzed C–B(sp<sup>3</sup>) Bond Formation through the Intermediacy of Cu–B(sp<sup>3</sup>) Complex
Zhanqiang Ye, Chun Yin Kwok, Sze Lam Lam, Linlin Wu, Hairong Lyu
Abstract
The vast majority of transition metal (TM) catalyzed borylative transformations rely on TM–B(sp 2 ) complexes. Contrastingly, the chemistry of TM–B(sp 3 ) species and their potential in catalytic borylation remain surprisingly underdeveloped, due probably to the lack of suitable boron(sp 3 ) reagents. Herein, we employ our recently developed sp 2 -sp 3 diboron reagent to successfully enable a copper-catalyzed hydroboration of allenes for C–B(sp 3 ) bond formation. A comprehensive mechanistic study, including the isolation and structural characterization of a Cu–B(sp 3 ) complex, substantiates the presence of a Cu–B(sp 3 ) intermediate in the catalytic cycle.
Topics & Concepts
ChemistryCopperCatalysisMedicinal chemistryOrganic chemistryCatalytic Cross-Coupling ReactionsOrganometallic Complex Synthesis and CatalysisOrganoboron and organosilicon chemistry