Copper-catalyzed multicomponent cascade synthesis of polyfunctionalized β-ketone sulfones

The multicomponent cascade reaction provides an efficient paradigm for the preparation of complex compounds in synthetic chemistry. Herein, we describe a copper-catalyzed multicomponent cascade reaction of vinyl azides and oxime esters with SO2 sources for the synthesis of polyfunctionalized (aryl-, alkyl-) & beta;-ketone sulfones. This protocol exhibits high step economy and excellent selectivity, and the target products can be produced in good yields with a low-cost copper catalyst under mild reaction conditions. Four new chemical bonds are formed in one pot through a series of processes including radical relay, radical addition, hydrogen abstraction, hydrolysis or oxidation. The gram-scale and four-component cascade reactions related to initial feedstocks of vinyl azides highlight the practicality and efficiency of this method.