Functionalization of an iridium–diamidocarbene complex by ligand-based reactions with titanocene and zirconocene sources

A (tBu-DAC)Ir(COD)Cl complex (tBu-DAC = 1,3-bis(N-tert-butyl)diamidocarbene, COD = 1,5-cyclooctadiene) reacts with titanocene(II) and zirconocene(II) sources to form heterobimetallic complexes by metallocene coordination at the remote oxalamide binding site. Structural and spectroscopic data reveal the formation of a doubly-reduced [tBu-DAC]2− ligand upon metallocene complexation. The metallocene-substituted complexes catalyze benzaldehyde hydrosilation at rates over an order of magnitude faster than those observed with the parent iridium complex.

Graphical abstractLigand-based reactions of an iridium–diamidocarbene complex with titanocene(II) and zirconocene(II) sources generate heterobimetallic complexes. The electronic effect of metallocene binding is described, along with a comparison of the complexes as catalysts for benzaldehyde hydrosilation.Figure optionsDownload full-size imageDownload as PowerPoint slide