Synthesis of multisubstituted olefins through regio- and stereoselective silylborylation of an alkynylboronate/chemoselective cross-coupling sequences

摘要

A highly regio- and stereoselective silylborylation of an alkynylboronate is disclosed. PhMe_2Si-B_(pin) undergoes a Pd(OAc) _2/~tOctNC-catalyzed syn-addition to the alkynylboronate to yield 1-phenyl-1-silyl-2,2-diborylethene with high regioselectivity. The product 1-phenyl-1-silyl-2,2-diborylethene is then chemoselectively arylated by Suzuki-Miyaura coupling to afford (Z)-1-silyl-2-borylstilbene derivatives. This approach is extended to the synthesis of a tetraarylated olefin with four different substituents.