Synthesis, Characterization and Reactions of the Chiral Transfer Agent Dicarbonyl(triphenylphosphine)-[(4r)-phenyl-(1'r)-(1'-phenylethyl)-1-azabuta-1,3-diene]iron(0)

Abstract

The synthesis and room temperature single-crystal X-ray structural characterization of the title compound [( PhCH =CHCH= NCHMePh )Fe(CO)2(PPh3)] are described, the first optically pure 1-azabuta-1,3-diene adduct of iron(0) to be so recorded. Crystals are orthorhombic, P212121, a 20.197(6), b 14.09(1), c 11.094(5) Ǻ, Z 4; conventional R on |F| was 0.061 for 2217 independent 'observed' (I> 3σ(I)) reflections. This compound has been employed to transfer the Fe(CO)2(PPh3) moiety to cyclic 1,3-dienes to give new complexes, including the first example of optically active dicarbonyl ( triphenyl - phosphine )(η4-1-methoxycyclohexa-1,3-diene)iron.

The chemistry of (1-azabuta-1,3-diene)tricarbonyliron(0) complexes

“…Synthesis of diastereomeric complexes by photolysis of a pre-formed substituted iron carbonyl and a chiral 1-azabuta-1,3-diene ligand has also been reported [13]. For example, reaction of Fe(CO) 4 PPh 3 with R-1-(1-phenylethyl)-2-methyl-4-phenyl-1-azabuta-1,3-dienes (27) under photochemical conditions leads to the formation of R,R and R,S complexes 28 and 29 (Scheme 6).…”