Synthesis and Characterization of Planar-Chiral Cyclopentadienyliron Complexes (S)- and (R)-{η5-[1-Ph2(OH)C-2-Me-4-PhC5H2]}Fe(CO)2R (R = C⋮CPh, Me, SO2Me)

Abstract

The first enantiomerically pure planar-chiral cyclopentadienyliron complexes, (S)- and (R)-η5-CpcFe(CO)2R [Cpc = 1-hydroxydiphenylmethyl-2-methyl-4-phenylcyclopentadienyl; R = C⋮CPh (6), Me (8)], in which the locus of chirality is in the cyclopentadienyl center, were synthesized from CpaFe(CO)2I (4a: Cpa = 1-(−)-menthoxycarbonyl-2-methyl-4-phenylcyclopentadienyl) and CpbFe(CO)2I (4b: Cpb = 1-(+)-menthoxycarbonyl-2-methyl-4-phenylcyclopentadienyl) and were isolated as a diastereomerically pure form by fractional recrystallization. The molecular structures of 4a and 4b, including the absolute configuration, have been established by an X-ray crystallographic analysis based on the configuration of the (−)- and (+)-menthyl groups.