NMR studies on the rhodium(I) chelates of two 2,3‐bis(<i>O</i>‐diphenylphosphino)‐β‐D‐glucopyranosides: Potent catalysts for enantioselective reactions

Abstract

Abstract The 1 H, 13 C and 31 P NMR spectra of the 2,3‐bis( O ‐diphenylphosphino)‐β‐D‐glucopyranoside rhodium(I) chelates 1 and 2 were recorded in CDCl 3 solution and the spectral assignments were performed with 1D and 2D techniques. In both complexes the pyranoside ring has a chair conformation. For the seven‐membered chelate ring a twist‐boat conformation could be established for 1, whereas for 2 the expected twist‐chair conformation was found. The phenyl groups at the P atoms show unhindered rotation about the C phenyl P bonds and the COD ligand seems to rotate about the RhCOD axis slowly on the NMR time‐scale.