new class of 2-methylallyl ruthenium chiral diphosphines 1 are efficient in asymmetric hydrogenation of α,β unsaturated acids and allylic alcohols. The related chiral halogen-containing ruthenium catalysts 2 are prepared from 1 or in situ from (COD)Ru(η)3-(CH2)2CHCH3)2 by ligand exchange with the chelatingdiphosphine followed by protonation (HX) in acetone. This procedure allows rapid screening of chiral
Asymmetric synthesis of long chain β-hydroxy fatty acid methyl esters as new elastase inhibitors
作者:Belma Hasdemir、Hülya Çelik Onar、Ayşe Yusufoğlu
DOI:10.1016/j.tetasy.2012.07.004
日期:2012.7
methyl esters with an even carbon chain length of 12–20 1b–5b were synthesized by three different asymmetric reduction methods I, II III from their corresponding β-keto methyl esters 1a–5a with the aim of determining their elastase activities. In method I, chiral catalyst A was prepared fromchiral ligand (R)-binaphthol 1, while in method II, chiral catalyst B was synthesized from (2R,3R)-diisopropyl tartrate
A general preparation of chiral ruthenium(II) catalysts and the homogeneous enantioselective hydrogenation of prochiral olefins and keto groups are presented. Some applications to the synthesis of biologically active compounds are reported. (C) 1998 Elsevier Science S.A. All rights reserved.
FEICHTER, C.;FABER, K.;GRIENGL, H., TETRAHEDRON LETT., 30,(1989) N, C. 551-552