252005-45-1Relevant academic research and scientific papers
Rhodium complexes with chiral aminophosphinite derivatives of ephedrine
Kuznetsov, Vladimir F.,Facey, Glenn A.,Yap, Glenn P. A.,Alper, Howard
, p. 4706 - 4711 (1999)
Aminophosphinites Ph2POCHPhCHMeNMeR (2a-c: a, R = H; b, R = Me; c, R = Ph2-CH), prepared from the corresponding N-substituted (1S,2R)-ephedrines, cleanly react with [Rh(CO)2Cl]2 in benzene, affording complexes with P,N-chelating (3a, 4b) or monodentate (5b,c and 7c) ligands, depending on the steric bulk of the amino group and metal-to-ligand ratio. Treatment of the chloro-bridged dimer 7c with AgClO4 in methylene chloride gives the cationic complex 8c, containing not only P,N-chelating aminophosphinite but also a Ph group of a N-diphenylmethyl fragment coordinated to Rh in an unusual η2 fashion. Formation of the chiral center at nitrogen occurs stereoselectively, and complexes 3a and 8c exist as single diastereomers in the solid state and in solution. The structures of 3a and 8c were established by single-crystal X-ray diffraction.
