Organozinc pivalates for modular Cobalt-Catalyzed carbosulfonylation of 1,3-Enynes

Salt-stabilized organozinc pivalates display crucial counterion-effect by OPiv-coordination, which steer an efficient cobalt-catalyzed 1,4-carbosulfonylation of 1,3-enynes with sulfonyl chlorides under simple and mild reaction conditions. Notably, both aryl and alkyl zinc pivalates show superior reactivity compared to conventional halide-supported organozinc reagents, thus providing an expedient access to the preparation of highly functionalized α-allenyl sulfones via cascade C–C/C–S bond formation. Moreover, late-stage modifications of drug-like compounds and facile transformations of the resulting allenes illustrate the synthetic utility of this protocol.