Synthesis of α-Boryl-α-Substituted Allylboronates from Propyne

Abstract

A novel method for the two-step synthesis of αboryl-α-substituted allylboronates from propyne is described. These allylboronates are prepared by the Co-catalyzed 1,1diboration reaction of propyne with B 2 pin 2 , followed by the basemediated alkylation reaction of 1,1-di(boryl)propene at the αposition. Computational studies revealed the origins of observed reactivity and selectivity in the base-mediated alkylation reaction. The resulting α-boryl-α-methyl-allylboronate is applied to the allylation of aldehydes, which gives homoallylic alcohols with a trisubstituted alkene moiety.