Chiral organometallic NADH mimics: preparation and X-ray crystal structure of racemic (RS)-[Fe(η5-C5H5)(CO)(PPh3)(1-methyl-1,4-dihydronicotinoyl)] and homochiral (R)-(–)-[Fe(η5-C5H5)(CO){PPh2(O-[(–)-menthyl])}(1-methyl-1,4-dihydronicotinoyl)] and asymmetric reduction of ethyl benzoylformate

Abstract

The racemic complex (RS)-[Fe(η⁵-C₅H₅)(CO)(PPh₃)(1-methyl-1,4-dihydronicotinoyl)] has been prepared and shown to function as a NADH mimic. An X-ray crystal structure revealed that one face of the 1,4-dihydronicotinoyl moiety is essentially blocked by the triphenylphosphine ligand. The homochiral complex (R)-(–)-[Fe(η⁵-C₅H₅)(CO)(PPh₂(O-[(–)-menthyl])](1-methyl-1,4-dihydronicotinoyl)] possessing the sterically demanding chiral auxiliary [Fe(η⁵-C₅H₅)(CO){PPh₂(O)-(–)menthyl)}] at C-3 has also been prepared and shown to reduce ethyl benzoylformate to ethyl mandelate in 52% enantiomeric excess by a combination of steric and chelation control.