Facile synthesis of alkyl- and arylboronate esters enabled by a carbon nanotube supported copper catalyst

Abstract

An efficient synthesis of alkylboronate esters via alkyl halide borylation catalysed by copper nanoparticles stabilised on nitrogen-doped carbon nanotubes (N-CNT) is reported. This nanocatalyst provides practical access to alkylboronate esters at room temperature in 1 h, with good functional group tolerance. The procedure is also applicable to the borylation of benzyl chlorides and bromides. Radical clock experiments suggest that the reaction involves a radical pathway. The catalyst can be recycled up to ten runs without appreciable loss in the activity. In addition, we demonstrated the use of this supported copper catalyst for the anti-Markovnikov-selective hydroboration of vinylarenes and borylation of aryl halides with B₂pin₂, providing alkyl- and arylboronate esters, respectively, in good to excellent yields.