Reduction asymetrique catalysee par des complexes de metaux de transition IV. synthese d'amines chirales au moyen d'un complexe de rhodium et d'isopropylidene dihydroxy-2,3 bis(diphenylphosphino)-1,4 butane (diop)

Abstract

A chiral rhodium complex with (+)-diop as ligand is used as a catalyst in asymmetric synthesis leading to amines and N-acyl derivatives. Two kinds of reactions are investigated: asymetric hydrogenation of enamides and hydrosilylation of imines. Good optical yields are observed in the synthesis of N-acetyl α-phnenylethylamine (e.e. 45%) and N-acetyl α-phenylpropylamine (e.e. 83%). A strong solvent effect is observed, which can reverse the absolute configuration of tN-acetyl-α-phenylethylamine obtained by reduction of its enamide precursor. N-Benzyl-α-phenyl ethylamine is prepared by hydrosilylation with 65% optical purity. An asymmetric synthesis of 1,2,3,4-tetrahydropapaverine (e.e 38%) and related compounds is described.