Chiral aminophosphonite-phosphite ligands: synthesis and use in platinum- and rhodium-based enantioselective hydroformylation of styrene. Crystal structure of [(S)-N-(2,2′biphenoxyphosphino)-2-(2,2′biphenoxyphosphinoxymethyl)pyrrolidine]dichloroplatinum(I

New chiral unsymmetrical ligands containing deficient phosphorous moieties based on (S)-prolinol and (S)-oxoprolinol have been synthesised and used as chiral auxiliaries for the platinum- and rhodium-catalysed enantioselective hydroformylations of styrene. The new ligands are obtained readily by reaction of the amino alcohols with a chlorophosphonite. The beneficial effect induced by the electron-deficient phosphorous ends provided the branched aldehyde in up to 44% ee. A crystal structure of the platinum complex 5 is described.