Enantioselective copper-aminopyridine-catalyzed aza-Henry reaction with chelating N-(2-pyridyl)sulfonyl imines

This article describes a copper-catalyzed aza-Henry reaction. Copper complexes of camphor-derived aminopyridines catalyze the addition of nitromethane to N-(2-pyridyl)sulfonyl aldimines to give the corresponding β-nitrosulfonamides with good yields and variable enantiomeric excesses (up to 83%). An example of transformation of these compounds into N-(2-pyridyl)sulfonyl-α-amino acids and deprotection of the sulfonamide with Mg–MeOH is provided. Chirality 24:441–450, 2012. © 2012 Wiley Periodicals, Inc.