Visible light-induced strain-release transformations of bicyclo[1.1.0]butanes

Abstract

Bicyclo[1.1.0]butanes, as structurally unique compounds with high strain energy and diverse chemical properties, are becoming increasingly popular building blocks in organic and pharmaceutical chemistries. Strain-release transformation of bicyclo[1.1.0]butanes has received great attention from chemists as it is atom- and step-economical, and significant achievements have been made in this field. Visible-light photocatalysis, with its green and sustainable properties, enriches the strain-release strategy through an electron transfer or energy transfer pathway under mild conditions. In this review, we highlight the latest advancements in visible-light-induced strain-release reactions of bicyclobutanes, with a particular focus on the reaction mechanism. Organization of the content follows a subdivision based on reaction and product classes. Advances in obtaining unique chemical architectures continue to be breakthroughs in this fascinating field of research.