Rhodium-catalyzed direct ortho-alkenylation of phenyl sulfones with alkynes utilizing sulfonyl function as modifiable directing group

Abstract

The ortho-selective alkenylation of phenyl sulfones with alkynes proceeds effectively in the presence of a cationic Cp*-rhodium(III) catalyst together with an appropriate carboxylic acid involving regioselective C–H bond cleavage directed by the sulfonyl function. An (ortho-alkenylated phenyl) methyl sulfone prepared by this hydroarylation method undergoes palladium-catalyzed α-arylation and subsequent diastereoselective cyclization to directly produce the corresponding thiochromane 1,1-dioxide derivatives.