Aminophosphanes derived from chiral β-aminoalcohols and carbonyliron complexes thereof

Phosphinites 2 and 4 derived from (-)-N-methylephedrine (1) and(+)-N-methyl-Psi-ephedrine (3), respectively are described. The synthesis of the chiral potassium hydridoferrate complex 8 from `N-methyl-diphenylephos' (2) and KHFe(CO)(4) was less selective than that of the previously described chiral zwitterionic hydride 7 from 'N,N-dimethyl-diphenylephosium' (6) and KHFe(CO)(4). Phosphines corresponding to deoxy derivatives of 'ephos' 2 and 'ephosium' 6 were envisaged. A stereoselective conversion of 2 to the hydrohexafluorophosphate of the N-methyl-diphenyldeoxyephos oxide isomer (5) is reported, and an approach to the 'N,N-dimethyl-diphenyldeoxyephosium? (A) has been explored by stereoselective chlorination of the quaternary N,N-dimethylephedrium (11). Likewise, 'N,N,N-trimethyl-diphenyldeoxyvalphosium' (B) was envisaged by chlorination of (+)-N,N,N-trimelhylvalinolium (14). In the presence of Ph2PLi, however, the chlorides 12a and 16 underwent elimination reactions instead of Cl- substitution, and the phosphines A and B did not form. In a reverse complexation-quaternization strategy, the 'N,N-dimethyl-diphenyldeoxyvalphos' - Fe(CO)(4) complex (20) has been selectively prepared and subsequently converted to the corresponding ammonium complexes 21 and 20.HOTf. (C) 1999 Elsevier Science S.A. All rights reserved.