Recent advances in synthetic methodologies for transition metal-free Ullmann condensation reactions

Abstract

The enormous utility and significance of carbon–heteroatom compounds has stimulated the development of various transformations for coupling reactions. Although substantial improvements have been made in this field, formation of carbon–heteroatom bonds still remains a challenge to synthetic chemists, owing to employment of costly metal catalysts, toxic solvents and stringent reaction conditions. Therefore, it is important to design alternative milder protocols for transition metal-free coupling reactions. Herein, we provide a concise view of recent advances in various transition metal-free methodologies for carbon–heteroatom bond formation. This review will hopefully fulfil the expectations of readers who are interested in advancements made in this field and are looking for an update.