Halogen bond-assisted radical relay cyclization to access alkynylated 2-pyrrolidones.

Abstract

In the present work, we disclose a photoinduced synthesis of diverse alkynylated 2-pyrrolidones from N-allylanilides and arylacetylene bromides in moderate to good yields. The protocol operates under mild, catalyst-free conditions and employs inexpensive starting materials. Preliminary mechanistic studies support the involvement of radical intermediates, while UV-vis and NMR spectroscopic analyses provide evidence for halogen-bonding interactions between the substrates and the amine.