Halide-promoted pyridinylation of α-acylmethylides with 2-halo-1-methylpyridinium iodides as reagents

Abstract

Halide-promoted pyridinylation between α-acyl sulfonylmethylides and 2-halo-1-methylpyridinium iodides in a transition-metal-free protocol is described. A broad range of α-acyl sulfonylmethylides were transformed to bifunctionalized vinylsulfones in moderate to good yields, thereby providing a facile and practical approach for constructing methylthio- and pyridinoxyl-substituted vinylsulfones. The substrates can be extended to other acyl methylides. The reaction was shown to entail the formation of a C–O bond and consecutive breaking of C–S, C–Cl and C–N bonds.