Synthesis of isolable β-chloroenamines from N-alkoxylactams with organometallic reagents

Abstract

An efficient approach to access isolable β-chloroenamines via nucleophilic addition/dehydration of α-chloro N-alkoxylactam with organolithium and Grignard reagents is reported. This approach is amenable to the synthesis of β-chloroenamines by incorporating various C(sp) and C(sp²) units, such as alkyne, aryl, and heteroaryl moieties. The sequential reaction has a broad substrate scope and can be carried out for a scalable synthesis of β-chloroenamines. Control experiments suggested that both chloro and alkoxy groups act as inductive electron-withdrawing substituents to improve the stability of the enamines.