Synthesis and strain-release reactions of 1-azabicyclo[1.1.0]butanes: an update

Abstract

Azabicyclo[1.1.0]butanes (ABBs) are important synthetic tools for the preparation of functionalized azetidines. The transformations of azabicyclo[1.1.0]butanes generally involve the C3-N bond cleavage, which allows for the functionalization of the azacycles in the 1,3 positions. Recently, important advances in the field have led to the preparation of novel strained compounds from ABBs. Diverse spirocyclic and heterocyclic-substituted azetidines could be prepared, also harnessing enabling technologies. This review aims to discuss the most recent reports regarding the synthesis and transformations of ABBs as versatile synthons for the construction of pharmaceutically relevant heterocycles.