167955-67-1Relevant academic research and scientific papers
Asymmetric synthesis of (S,S)-(+)-1,1′-bis-(methyl-phenyl-phosphino) ferrocene
Kaloun,Merdes,Genet,Uziel,Juge
, p. 455 - 463 (2007/10/03)
The asymmetric synthesis of 1,1′-bis-(methyl-phenyl-phosphino) ferrocene 1 is described using the oxazaphospholidine borane complex 5 as synthon. Two strategies were investigated, based either on P-C bond formation by ring opening of complex 5 with the 1,1′-dilithio ferrocene 10, or on homocoupling of the cyclopentadienyl-methyl-phenyl-phosphine borane 2 anion with FeCl2. The first leads to a diastereomeric mixture of the diphosphine 1 in a 55:45 ratio, and the low stereoselectivity is explained by the steric hindrance of the ferrocene dianion. In the second strategy, the (R)-cyclopentadienyl phosphine borane 2 (85% ee) was prepared by the reaction of CpNa with the optically active chlorophosphine borane 14, derived from the aminophosphine borane 6a. The coupling of 2 leads to the 1,1′-diphosphino ferrocene borane 13, which is obtained diastereomerically pure by recrystallization, then decomplexed to the corresponding (S,S)-diphosphine 1.
1,1'-Bis(methylphenylphosphanyl)ferrocene: Synthesis and Complexes with the Tetracarbonylchromium Fragment
Herberich, Gerhard E.,Moss, Stefan
, p. 689 - 694 (2007/10/03)
1,1'-Bis(methylphenylphosphanyl)ferrocene (mppf) (2) was synthesized from dilithioferrocene and PMePh(OC6H4-4-Me).The diastereomers rac-2 and meso-2 were separated by fractional crystallization from ethanol.The tetracarbonylchromium complexes (rac-2)Cr(CO)4 (rac-5) and (meso-2)Cr(CO)4 (meso-5) were obtained photochemically from hexacarbonylchromium and mppf in near quantitative yield.The structures of rac-2, rac-5, and meso-5 were determined by X-ray crystallographic analysis. - Keywords: Ferrocene, 1,1'-bis(methylphenylphosphanyl)-; Chromium, carbonyl-, phosphane derivatives
