SYNTHESIS OF CHIRAL DEPSIPEPTIDE BUILDING BLOCK VIA ASYMMETRIC HYDROSILYLATION
作者:Jin-shui Yao、You-shi Wu
DOI:10.1081/scc-120002401
日期:2002.1.1
ABSTRACT Asymmetric hydrosilylation of N-(α-ketoacyl)-α-amino esters was performed, catalyzed by rhodium(I) complex of chiral 2-(2-pyridyl)-4-carbomethoxy-1,3-thiazolidine or Rh(PPh3)3Cl. The N-(α-hydroxyacyl)-α-amino esters were synthesized in high stereoselectivity.
Amino acid methyl esters were used as amine nucleophiles in palladium catalysed aminocarbonylation of iodobenzene and iodoalkenes (1-iodo-cyclohexene and 17-iodo-androst-16-ene). 2-Oxo-carboxamide type derivatives can be isolated as a result of double CO insertion by using iodobenzene as a substrate at elevated carbon monoxide pressure. On the contrary, carboxamides of expected structure were obtained exclusively in excellent yields in the whole pressure range by using iodoalkenes. The aminocarbonylation of 17-iodo-androst-16-ene in [bmim][PF6] or [bmim][BF4] (where bmim=1-butyl-3-methyl-imidazolium cation) ionic liquids was also carried out and the ionic liquid-catalyst mixtures have been reused several times with only a small loss of activity. (C) 2004 Elsevier Ltd. All rights reserved.