Alkene Isomerization-Hydroboration Promoted by Phosphine-Ligated Cobalt Catalysts

Generated in situ from air-stable cobalt precursors or readily synthesized using NaHBEt3, (PPh3)(3)CoH(N-2) was found to be an effective catalyst for the hydroboration of alkenes. Unlike previous base-metal catalysts for alkene isomerizationhydroboration which favor the incorporation of boron at terminal positions, (PPh3)(3)CoH(N-2) promotes boron incorporation adjacent to pi-systems even in substrates where the alkene is at a remote position, enabling a unique route to 1,1-diboron compounds from alpha,omega-dienes.