Complementary Copper-Catalyzed and Electrochemical Aminosulfonylation of -Homoallyl Benzimidates and -Alkenyl Amidines with Sodium Sulfinates.

A complementary copper-catalyzed and electrochemical aminosulfonylation of -homoallyl benzimidates and -alkenyl amidines with sodium sulfinates was developed. The terminal alkene substrate produced sulfone-containing 1,3-oxazines and tetrahydropyrimidines in the presence of Cu(OAc), AgCO, and DPP, and under similar reaction conditions, sulfonylated tetrahydro-1,3-oxazepines were prepared from 1-aryl-substituted -homoallyl benzimidates in moderate to good yields. For certain electron-rich 1,1-diaryl-substituted alkene substrates, the corresponding tetrahydro-1,3-oxazepines could also be obtained in similar or even higher yields via a green electrochemical technique.