Sequential one-pot synthesis of 3,5- disubstituted-1H-pyrazoles from oxime acetates and cyclic sulfamidate imines

Abstract

Efficient CuCl catalyzed domino reaction of various oxime esters with cyclic sulfamidiate imines provides a new pathway to a diverse set of pyrazoles in good yields. This one-pot two-step sequential reaction proceeds between cyclic sulfamidate imines and oxime esters to afford intermediate 3aa (2-phenyl-1,10b dihydrobenzo[e]pyrazolo[1,5-c] [1,2,] oxathiazine 5,5-dioxide), followed by the addition of strong base 1,5-diazabicyclo[4.3.0]non-5-ene.