Ni(0)-catalyzed 1,4-selective diboration of conjugated dienes.

A catalytic stereoselective 1,4-diboration of conjugated dienes with B(2)(pin)(2) was accomplished with Ni(cod)(2) and PCy(3) as the catalyst. This reaction broadens the substrate scope of current methods for catalytic diene diboration by including internal and sterically hindered dienes, and it proceeds efficiently at low catalyst loadings. The intermediate allylboronate was oxidized to the stereodefined allylic 1,4-diol.