Chiral phosphine ligands derived from sugars 6 Syntheses and spectroscopic studies on rhodium complexes with a new type of chiral phosphines

摘要

Methyl 4,6-O-benzylidene-3-deoxy-3-(diphenylphosphino)-alpha-D-altropyranoside (1) and methyl 4,6-O-benzylidene-2-deoxy-2-(diphenylphosphino)-alpha-D-altropyranoside (2) were prepared from methyl 2,3-anhydro-4,6-O-benzylidene-alpha-D-mannopyranoside and methyl 2,3-anhydro-4,6-O-benzylidene-alpha-D-allopyranoside, respectively, via regioselective and stereospecific ring-opening reactions in high yields. Ligands 1 and 2 reacted with [{Rh(CO)(2)Cl}(2)] to give trans-[(P')(2)Rh(CO)Cl] (3, P' = 1; 4, P' = 2). Compounds 1-4 have been characterized by elemental analyses, multinuclear NMR, IR and Raman, mass spectroscopic investigations. Copyright (C) 1996 Elsevier Science Ltd