Cyclometallation of Heavier Tetrylenes: Reported Complexes and Applications in Catalysis

Heavier tetrylenes (HTs), which are the heavier analogues of carbenes, have been used as ligands in transition metal chemistry for more than 50 years. Having in mind that cyclometallation is a valuable tool to modify ligand scaffolds, with important implications in inorganic and organic chemistry, this microreview discusses in detail the reactions that have afforded complexes with cyclometallated HTs. To date, eight HT ligands, covering only silylenes and germylenes, have been reported to undergo cyclometallation, all of them on late transition metals. Structural and spectroscopic data of the isolated complexes as well as mechanistic information related to the cyclometallation processes are collected and discussed. Additionally, this minireview also surveys the catalytic applications found so far for cyclometallated HT complexes.

Automated summary

This article discusses the use of heavier tetrylenes as ligands in transition metal chemistry, focusing on reactions that have produced complexes with cyclometallated HTs. Eight HT ligands have been reported to undergo cyclometallation, with some catalytic applications also being surveyed.