Asymmetric synthesis of syn- and anti-α-deuterio-β3-phenylalanine derivatives
摘要:
The conjugate addition of lithium (S)-N-benzyl-N-(alpha-methylbenzyl)amide to a range of aryl substituted tert-butyl cinnamate esters followed by reaction of the resultant lithium beta-amino enolates with D2O provides access to anti configured alpha-deuterio-beta-aminocinnamate esters in high dr. The corresponding syn configured diastereoisomers were also obtained with high diastereoselectivity via the conjugate addition of lithium (5)-N-benzyl-N-(alpha-methylbenzyl)amide to a range of tert-butyl alpha-deuteriocinnamate esters followed by reaction of the resultant lithium beta-amino enolates with 2-pyridone. After deprotection both the syn- and anti-diastereoisomers of the corresponding alpha-deuterio-beta(3)-amino acids can be isolated in high dr. (C) 2011 Elsevier Ltd. All rights reserved.
Phosphine-free palladium-catalyzed MizorokiâHeck reaction was performed using ball-milling in polyethylene glycol under mild conditions. Good to excellent yields of coupling products were obtained. This activation technique also allowed the concomitant formation of round shaped PdâPEG nanoparticles that were characterized by TEM analysis.
Asymmetric synthesis of syn- and anti-α-deuterio-β3-phenylalanine derivatives
作者:Stephen G. Davies、Emma M. Foster、Catherine R. McIntosh、Paul M. Roberts、Timothy E. Rosser、Andrew D. Smith、James E. Thomson
DOI:10.1016/j.tetasy.2011.06.008
日期:2011.5
The conjugate addition of lithium (S)-N-benzyl-N-(alpha-methylbenzyl)amide to a range of aryl substituted tert-butyl cinnamate esters followed by reaction of the resultant lithium beta-amino enolates with D2O provides access to anti configured alpha-deuterio-beta-aminocinnamate esters in high dr. The corresponding syn configured diastereoisomers were also obtained with high diastereoselectivity via the conjugate addition of lithium (5)-N-benzyl-N-(alpha-methylbenzyl)amide to a range of tert-butyl alpha-deuteriocinnamate esters followed by reaction of the resultant lithium beta-amino enolates with 2-pyridone. After deprotection both the syn- and anti-diastereoisomers of the corresponding alpha-deuterio-beta(3)-amino acids can be isolated in high dr. (C) 2011 Elsevier Ltd. All rights reserved.