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

A complementary copper-catalyzed and electrochemical aminosulfonylation of O -homoallyl benzimidates and N -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) 2 , Ag 2 CO 3 , and DPP, and under similar reaction conditions, sulfonylated tetrahydro-1,3-oxazepines were prepared from 1-aryl-substituted O -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.