Catalyst Design of Vaska-Type Iridium Complexes for Highly Efficient Synthesis of π‑Conjugated Enamines

The appropriate design of a ligand (L) in IrCl­(CO)­(L)2 (4) realized the efficient synthesis of π-conjugated enamines possessing hole-transport properties. The iridium complex with electron-withdrawing phosphorus ligands catalyzed the hydrosilylation of amides to the corresponding silylhemiaminals, which were transformed to the enamines by heat or by treatment with acids. High catalytic efficiency (TON > 10,000) was achieved, which made it possible for the residual iridium in the enamine product to be below 20 ppb.