Highly Regio- and Stereoselective Synthesis of Multialkylated Olefins through Carbozirconation of Alkynylboronates and Sequential Negishi and Suzuki-Miyaura Coupling Reactions

摘要

The regio- and stereoselective synthesis of multisubstituted olefins is one of the most challenging tasks in synthetic organic chemistry. Established synthetic methods to directly construct carbon-carbon double bonds, such as Wittig, Horner-Wadsworth-Emmons, or olefin metathesis have limitations and often afford inseparable mixtures of stereoisomers. Recent advances in carbometalation or bimetalation/ cross-coupling strategies have provided a facile entry to multisubstituted olefins, albeit often with problematic regio-and stereoselectivities. Although efficient multicomponent coupling reactions have been used to achieve the synthesis of multisubstituted olefins bearing aromatic substituents, a general approach to multialkylated olefins has yet to be defined.