Fun with (4+3)-Cycloadditions

This account describes how I began my adventure in the area of (4+3)-cycloadditions and then focuses on two ongoing projects: a new catalytic asymmetric (4+3)-cycloaddition and what might be described as the ‘rebirth’ of oxidopyridinium ion (4+3)-cycloaddition chemistry. References to other people’s work are made where appropriate. 1 Introduction 2 Asymmetric, Catalytic (4+3)-Cycloadditions 3 Oxidopyridinium Ions and (4+3)-Cycloadditions 4 Conclusions and the Future