TBN-mediated regio- and stereoselective sulfonylation & oximation (oximosulfonylation) of alkynes with sulfonyl hydrazines in EtOH/H2O

An alkyne difunctionalization cascade reaction was developed to generate alpha-sulfonylethanone oximes under metal-free conditions. The reaction features environmentally benign EtOH/H2O as a solvent, a broad substrate scope and easily scaled up for gramscale synthesis. The reaction mechanism was illustrated with UPLC, GC-MS and UPLC-tof/MS.