Palladium-Catalyzed α-Arylation of Meyers’s Chiral Bicyclic Lactams and a Deprotonative Ring-Opening Sideline

Abstract

Described is a deprotonative α-arylation reaction of Meyers’s chiral bicyclic lactams (MCBLs) under palladium catalysis, and a substrate-dependent post-transformation. When the bridgehead carbon of the MCBLs is substituted with a methyl or an ethyl group, the initial arylation product undergoes a further rearrangement reaction to give a conjugated framework. On the other hand, substrates bearing a bridgehead isopropyl or aryl group are converted into the corresponding exo-arylation products. Preliminary studies indicated that the rearrangement pathway was promoted by deprotonation and was independent of palladium catalysis. In addition to mechanistic interests, this study demonstrates a modular and divergent synthesis of functionalized lactams.

Key words

arylation - palladium catalysis - enolates - rearrangement - stereoselectivity - lactams

• References and Notes

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