Catalytic decarbonylation of aldehydes using iron(II) porphyrin complexes, and the crystal structure of (5,10,15,20-tetraphenylporphinato) bis(tri-n-butylphosphine)iron(II)
Belani, R.M., James, B.R., David Dolphin, and Rettig, S.J.
Can. J. Chem.
The crystal structure of (5,10,15,20-tetraphenylporphinato)bis(tributylphosphine)iron(II) (I) was determined. The molecule displays a relatively undistorted pseudooctahedral coordination geometry with Fe-P = 2.346(1) and Fe-N = 1.998(3) and 1.993(3)Å. In CH2Cl2 solution, I reacts with CO and aldehydes to generate the carbonyl(phosphine) derivative, and decarbonylation of phenylacetaldehyde to toluene becomes catalytic under an Ar stream. The aldehyde decarbonylations involve radical pathways via carbonyl loss from PhCH2C=O. The hydrogen abstraction/initiation reaction probably utilizes trace O2 (and possibly trace water); speculative mechanisms are discussed.