Enantioselective hydrogenation of some alpha,beta -unsaturated nitriles and their corresponding methyl esters bearing a phthalimidomethyl substituent at the alpha -carbon using Rh-DuPHOS catalysts afforded beta -amino acid precursors with modest e.e.s of up to 48%. Hydrogenation of the alpha,beta -unsaturated methyl esters using a Ru-BINAP catalyst gave higher e.e.s of up to 84%. Method development for the determination of the enantiomeric excesses of these derivatives using chiral HPLC is also reported. (C) 2001 Elsevier Science Ltd. All rights reserved.
Enantioselective hydrogenation of some alpha,beta -unsaturated nitriles and their corresponding methyl esters bearing a phthalimidomethyl substituent at the alpha -carbon using Rh-DuPHOS catalysts afforded beta -amino acid precursors with modest e.e.s of up to 48%. Hydrogenation of the alpha,beta -unsaturated methyl esters using a Ru-BINAP catalyst gave higher e.e.s of up to 84%. Method development for the determination of the enantiomeric excesses of these derivatives using chiral HPLC is also reported. (C) 2001 Elsevier Science Ltd. All rights reserved.
Enantioselective radical reactions. Evaluation of nitrogen protecting groups in the synthesis of β2-amino acids
作者:Mukund P. Sibi、Kalyani Patil
DOI:10.1016/j.tetasy.2006.01.018
日期:2006.2
We have investigated the effect of nitrogen protecting groups in radical addition trapping experiments leading to beta(2)-amino acids. Of the three N-protecting groups examined, the phthalimido group was optimal with respect to both yields and enantioselectivity. Additionally, radical additions to more complex acrylates were also investigated, which provided access to functionalized beta(2)-amino acids in modest selectivity. (c) 2006 Elsevier Ltd. All rights reserved.
A new enantioselective synthesis of β-amino acids
作者:Dilek Saylik、Eva M. Campi、Andrew C. Donohue、W.Roy Jackson、Andrea J. Robinson
DOI:10.1016/s0957-4166(01)00097-0
日期:2001.3
Enantioselective hydrogenation of some alpha,beta -unsaturated nitriles and their corresponding methyl esters bearing a phthalimidomethyl substituent at the alpha -carbon using Rh-DuPHOS catalysts afforded beta -amino acid precursors with modest e.e.s of up to 48%. Hydrogenation of the alpha,beta -unsaturated methyl esters using a Ru-BINAP catalyst gave higher e.e.s of up to 84%. Method development for the determination of the enantiomeric excesses of these derivatives using chiral HPLC is also reported. (C) 2001 Elsevier Science Ltd. All rights reserved.