[4+2]-Cycloaddition Reactions of Aza-o-quinone Methides with Fulvenes: Construction of Tetrahydroquinoline Derivatives

Abstract

AbstractAn efficient [4+2] cycloaddition reaction of fulvenes with aza-o-quinone methides, generated in situ from N-(o-chloromethyl)aryl sulfonamides with the assistance of a base, has been developed to afford a series of tetrahydroquinoline derivatives. The reaction tolerates a wide range of aza-o-quinone methides and fulvenes bearing four- to seven-membered rings to afford the corresponding tetrahydroquinolines in moderate to good yields. Based on a literature analysis, a plausible mechanism for this [4+2] cycloaddition is proposed.