Chiral derivatives of 1,2-benzenedisulfonimide as efficient Brønsted acid catalysts in the Strecker reaction

Abstract

Two chiral derivatives of 1,2-benzenedisulfonimide, namely 4-methyl-3,6-bis(o-tolyl)-1,2-benzenedisulfonimide and 4,5-dimethyl-3,6-bis(o-tolyl)-1,2-benzenedisulfonimide, have been easily synthesized in good overall yields (respectively 34% and 41%) by means of an eleven-step synthetic protocol from commercially available 2-methyl-6-nitroaniline or 2,3-dimethyl-6-nitroaniline. 4,5-Dimethyl-3,6-bis(1-naphthyl)-1,2-benzenedisulfonimide was also synthesized, but the overall yield from 2,3-dimethyl-6-nitroaniline was lower (9%). The atropisomers of these compounds have been resolved and (−)atropisomers have been demonstrated to be efficient chiral catalysts in the Strecker reaction.