Conjugate addition of sodium methanesulfinate to vinyl pyridines and diazines for the synthesis of aliphatic sulfones

A convenient method to introduce a sulfone group to pyridines and diazines is described. This efficient method involves the conjugate addition of sodium methanesulfinate to vinyl heterocycles. This process tolerates a wide variety of functional groups and is performed in the presence of acetic or trifluoroacetic acid. A one-pot, two-step synthesis of sulfones starting from the corresponding heteroaryl halide is also described.