Chemoselective Cu-Catalyzed Cross-Nucleophile Alkylarylation of Alkenes

We report a general cross-nucleophile alkene alkylarylation which adds two different boronic acids, an alkyl and an aryl, across a vinylarene to afford 1,1-diarylalkanes. The excellent chemoselectivity derives from the distinct reactivities of the two boronic acids: the alkylboronic acid is selectively oxidized to an alkyl radical while the arylboronic acid favors transmetalation with the Cu(II)-catalyst. Mechanistic studies suggest that Lewis acid-Lewis base interactions between in-situ generated boroxines and added amine are critical for selectivity. A scope of 37 examples is presented with structurally and electronically diverse alkyl, vinyl, and aryl coupling partners. The synthetic utility is demonstrated in the preparation of Pimozide and MCF-7 analogues.