General asymmetric synthesis of isoquinoline alkaloids. Enantioselective hydrogenation of enamides catalyzed by BINAP-ruthenium (II) complexes

…, M Ohta, M Tsukamoto, T Ohta, H Takaya…

Index: Kitamura; Hsiao; Ohta; Tsukamoto; Takaya; Noyori Journal of Organic Chemistry, 1994 , vol. 59, # 2 p. 297 - 310

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Citation Number: 146

Abstract

In the presence of a small amount of RuXz [(R)-or (S)-BINAPI (X= anionic ligand) a wide range of (Z)-2-acyl-l-benzylidene-1, 2, 3, 4-tetrahydroisoquinolines are hydrogenated to give the saturated produch in nearly quantitative yields and in high (up to 100%) optical yields. The enamide substrates are selectively prepared by N-acylation of the corresponding 1- benzylated 3, 4-dihydroisoquinolines under suitable acylation conditions; some crystalline ...