Asymmetric Synthesis Catalyzed by Chiral Ferrocenylphosphine–Transition Metal Complexes. I. Preparation of Chiral Ferrocenylphosphines

Abstract

As chiral ligands for transition metal complex catalyzed asymmetric reactions, various kinds of chiral ferrocenylphosphines, which have planar chirality due to 1,2-unsymmetrically substituted ferrocene structure and also have a functional group on the side chain of the ferrocene nucleus, were prepared. (S)-N,N-dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine [(S)-(R)-PPFA], (S)-N,N-dimethyl-1-[(R)-1′,2-bis(diphenylphosphino)ferrocenyl]ethylamine [(S)-(R)-BPPFA], and their dimethylphosphino derivatives were prepared by way of lithiation of optically resolved N,N-dimethyl-1-ferrocenylethylamine. The 1-(dimethylamino)ethyl group on the ferrocenylphosphines was converted stereospecifically by nucleophilic substitution reactions into 1-methoxy-, 1-hydroxy-, 1-diphenylphosphino-, and several 1-(dialkylamino)ethyl groups. 1-Diphenylphosphino-2-(dimethylaminomethyl)ferrocene (FcPN) was optically resolved via its phosphine sulfide dibenzoyltartaric acid salt. The relationship between CD spectra of the chrial ferrocenylphosphines and the configuration of their planar chirality is discussed.

Group 11 Metal Complexes with Unsymmetrical Bifunctional Ferrocene Ligands

“…[20][21][22][23] Examples are the aminophosphine 1-(N,N-dimethylamino)ethyl-1-diphenylphosphinoferrocene (ppfa) [24] and the diphosphines Josiphos [25] and Xyliphos (Scheme 1), [26,27] the latter of which is of great industrial importance. These phosphine derivatives are [Fc(CH 2 PPh 2 )(PPh 2 )] (L2) with gold(I), gold(III), silver(I), or copper(I) complexes afford mono-, di-, or trinuclear derivatives.…”

Synthesize, crystal structure, heat capacities and thermodynamic properties of a potential enantioselective catalyst

“…The assessments were reported in our previous studies [23,24]. The results indicated that the Table 3 The data of three reduplicate DSC experiments for DPFEB testing system of TMDSC was steady and the measurement result was reliable.…”

“…Preparation of (R c , S p )-PPFA As described in Scheme 1 [24], to a solution of (R)-Ugi's amine (7.2 g, 28 mmol) in Et 2 O (40 mL) was added dropwise n-BuLi (12 mL, 30 mmol, 2.5 M solution in hexane) at 298-300 K. The reaction mixture was stirred for another 1.5 h at room temperature. The mixture was then heated to reflux, followed by dropwise addition of chlorodiphenylphosphine (12.4 g, 56 mmol) dissolved in Et 2 O (20 mL).…”

Ferrocene-Based Chiral Phosphine-Triazines: A New Family of Highly Efficient P,N Ligands for Asymmetric Catalysis

“…In contrast to the distereomers (R c ,S p )-6a -f, however, the synthesis of (S c ,S p )-6g is somewhat more difficult. [10] Through the initial introduction of a trimethylsilyl-protected group and final deprotection by TBAF (tetrabutylammonium fluoride), (S c ,S p )-6g was synthesized in enantiomeric purity in a total yield of 43.1% as outlined in Scheme 2. By the reaction of a series of ferrocenylphosphine-amines (R c ,S p )-6a -f or (S c ,S p )-6g with various 4,6-disubstituted 2-chloropyrimidines or 2-chloro-1,3,5-triazines in refluxing ethanol in the presence of NaHCO 3 , the targeted P,N ligands 1 and 3 with the different heterocycles were easily prepared in 47.2 to 86.2% yields as outlined in Scheme 3.…”