The preparation of novel chiral auxiliaries SAMIQ/RAMIQ and their application in the asymmetric Michael addition
摘要:
A pair of novel chiral auxiliaries SAMIQ/RAMIQ was synthesized from L- or D-phenylalanine methyl ester hydrochloride over six steps in 45.8% and 44.4% yield, respectively. The SAMIQ-/RAMIQ-hydrazone methodology was applied for the asymmetric Michael addition of ketones to alpha,beta-unsaturated carboxylic acid methyl esters, which afforded 3-substituted-5-oxo-alkanoates in moderate to good yield (65-82%) with excellent enantioselectivity (ee=95.3%similar to>99.5%). (C) 2014 Elsevier Ltd. All rights reserved.
The preparation of novel chiral auxiliaries SAMIQ/RAMIQ and their application in the asymmetric Michael addition
摘要:
A pair of novel chiral auxiliaries SAMIQ/RAMIQ was synthesized from L- or D-phenylalanine methyl ester hydrochloride over six steps in 45.8% and 44.4% yield, respectively. The SAMIQ-/RAMIQ-hydrazone methodology was applied for the asymmetric Michael addition of ketones to alpha,beta-unsaturated carboxylic acid methyl esters, which afforded 3-substituted-5-oxo-alkanoates in moderate to good yield (65-82%) with excellent enantioselectivity (ee=95.3%similar to>99.5%). (C) 2014 Elsevier Ltd. All rights reserved.