Mesoionic imines: strong N-donors, electronic ambivalence and applications in catalysis

Mesoionic imines (MIIs) based on a 1,2,3-triazole core have been popularized in the past ca. 5 years. In this review article we discuss the synthesis, coordination ability and the structural and spectroscopic properties of this fascinating class of electronically ambivalent compounds. Apart from this, we also discuss the utility of MIIs and their compounds in directed C–H activation reactions, and in the activation and conversion of small molecules such as alkynes and CO2. Based on the current state of the art, we touch upon possible future developments of the chemistry of these classes of molecules.