Dedicated to Professor Emeritus Branko Stanovnik, University of Ljubljana, on the occasion of his 80th birthday
Abstract
Although the first example of copper-catalyzed azomethine imine–alkyne cycloaddition (CuAIAC) was published only a year after the seminal papers of Meldal and Sharpless on Cu-catalyzed azide–alkyne cycloaddition (CuAAC), the CuAIAC reaction has remained overlooked by the synthetic community for almost a decade. Since 2010, however, CuAIAC reaction started to emerge as a promising supplement to the well-known CuAAC reaction. The present review surveys primarily the literature on CuAIAC reaction since 2003. Beside this, azomethine imine–alkyne cycloadditions catalyzed by other metals, selected examples of metal-free reactions, and related [3+3] and [3+4] cycloadditions of azomethine imines are presented. All these experimental data indicate the viability of CuAIAC in organic synthesis and the applicability in ‘click’ chemistry.
1 Introduction
2 Reactions with Acyclic Azomethine Imines
3 Reactions with C,N-Cyclic Azomethine Imines
4 Reactions with N,N-Cyclic Azomethine Imines
5 Reactions with C,N,N-Cyclic Azomethine Imines
6 The Mechanism of the CuAIAC Reaction
7 Conclusions and Outlook
Key words
azomethine imines - alkynes - cycloadditions - click chemistry - pyrazolines
