Copper-catalyzed boron radical-enabled 1,4-selective diboryldimerization of styrenes

Abstract

A copper-catalyzed, boron radical-mediated strategy for the 1,4-diboryldimerization of styrenes is described. This method enables the direct coupling of two olefin units with concomitant installation of two boryl groups, providing efficient access to 1,4-diboryl-1,4-diphenylbutane derivatives from simple starting materials. The reaction proceeds under mild conditions and exhibits broad functional group tolerance, accommodating various substituted styrenes with good efficiency and, in many cases, high diastereoselectivity. Mechanistic investigations, including radical-trapping and control experiments, support a pathway involving boryl and carbon-centered radical intermediates, distinguishing this process from classical two-electron migratory insertion mechanisms. This work offers a practical and step-economical route to extended diborylated frameworks and highlights the potential of merging copper catalysis with radical chemistry for olefin dimerofunctionalization.