Stereoselective Nucleophilic Aromatic Substitution of 2-Pyridinotropones with β,β-Disubstituted Enesulfinamides

Abstract

Metalloenamines, formed through the deprotonation of enesulfinamides possessing two sterically and electronically similar β-substituents (e.g., Me and Et), undergo stereoselective nucleophilic aromatic substitution (SNAr) reactions with 2-pyridinotropones. This transformation affords functionalized tropones featuring a synthetically challenging acyclic quaternary carbon stereocenter. The well-defined geometry of the carbon–carbon double bond in the enesulfinamides, together with the chiral induction provided by the sulfinyl group, facilitates precise stereocontrol during the SNAr reaction. This approach complements existing methodology involving the chiral enamine-catalyzed SNAr of tropones with aldehydes α,α-disubstituted by one aryl and one alkyl substituent.