Synthesis of 4,5-Benzotropone Pi-Complexes of Iron, Rhodium and Iridium and Their Potential Use in Catalytic Borrowing Hydrogen Reactions

The synthesis of rhodium, iridium, and iron pi-complexes bearing 4,5-benzotropone ligands are reported. X-ray crystallographic analyses revealed that a tropone core coordinates to a metal center in a eta⁴ manner with a tub-form geometry. Some of the benzotropone p-complexes exhibited catalytic activity for the N-alkylation of aniline via borrowing hydrogen.