<i>P*</i>,<i>N</i>‐Bidentate Amino Phosphoramidites: New Highly Effective Ligands for Pd‐Catalysed Asymmetric Allylic Substitution

Abstract

Abstract New chiral P* , N ‐hybrid amino phosphoramidites have been obtained by one‐step phosphorylation of amino alcohols. Complexation of the new ligands with [Rh(CO) 2 Cl] 2 and [Pd(allyl)Cl] 2 gave the corresponding chelate complexes [Rh(CO)Cl(η 2 ‐P,N)] and [Pd(allyl)(η 2 ‐P,N)] + BF 4 − , which subsequently afforded up to 90% ee in the asymmetric Pd‐catalysed sulfonylation of 1,3‐diphenyl‐2‐propenyl acetate with sodium p ‐toluenesulfinate. In the enantioselective alkylation of 1,3‐diphenyl‐2‐propenyl acetate with dimethyl malonate, up to 98% enantioselectivity was achieved with [Pd(allyl)(η 2 ‐P,N)] + BF 4 − complexes as chiral catalysts. (© Wiley‐VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2004)