Sodium dithionite as a bifunctional reagent for the cyanoalkylsulfonylation of Morita–Baylis–Hillman acetates with cycloketone oxime esters

Abstract

For the first time, an inexpensive and readily available inorganic salt, sodium dithionite (Na₂S₂O₄), has been demonstrated for the single electron reduction of cycloketone oxime esters. The resultant cyanoalkyl radicals are efficiently transformed into cyanoalkyl sulfinates and subsequently intercepted by Morita–Baylis–Hillman (MBH) acetates. This novel methodology provides access to a wide variety of allylic cyanoalkylsulfones in a chemo-, regio- and stereo-selective manner. Importantly, this approach is transition-metal-, light-irradiation-free, offering a complementary pathway to existing cyanoalkylsulfonylation routes.