Chin. J. Org. Chem. ›› 2016, Vol. 36 ›› Issue (9): 2242-2246.DOI: 10.6023/cjoc201601045 Previous Articles     Next Articles



王沁婷, 赵帅, 金雷, 陈新   

  1. 常州大学制药与生命科学学院 常州 213164
  • 收稿日期:2016-01-31 修回日期:2015-03-17 发布日期:2016-04-07
  • 通讯作者: 陈新
  • 基金资助:


Synthesis of Fmoc-protected (S)-3,5-Dibromophenylalanine in the Presence of a Phase Transfer Catalyst or a Chiral Catalyst

Wang Qinting, Zhao Shuai, Jin Lei, Chen Xin   

  1. School of Pharmaceutical Engineering & Life Science, Changzhou University, Changzhou 213164
  • Received:2016-01-31 Revised:2015-03-17 Published:2016-04-07
  • Supported by:

    Project supported by the National Natural Science Foundation of China (No.21272029).

Two methods of catalytic asymmetric synthesis of (S)-3,5-dibromophenylalanine are presented. One approach is to use asymmetric alkylation reaction starting from diphenylimine glycine tert-butyl ester and 3,5-dibromobenzyl bromide, with O-allyl-N-9-anthracene methyl bromide cinchonidine as phase-transfer catalyst, the (S)-3,5-dibromophenylalanine derivative was obtained (up to 94.9% ee). The optimized conditions of asymmetric phase transfer catalytic alkylation are explored. Another method is to employ asymmetric hydrogenation starting from 2-acetylamino-3-(3,5-dibromophenyl)acrylic acid with bis(1,5-cyclooctadiene)rhodium(I) trifluoromethanesulfonate and (R)-diphenylphosphino-N-methyl-1-[(S)-2-diphenyl-phos-phino)ferrocenyl]ethylamine[(R)-methyl BoPhoz] as chiral catalyst. (S)-3,5-Dibromophenylalanine hydrochloride was obtained after hydrolysis. By Fmoc protection, Fmoc-(S)-3,5-dibromophenylalanine was obtained (up to 94.7% ee). By comparison of the two methods, the first one gives higher overall yield and a little bit better selectivity, and is more suitable for the synthesis of other chiral dihalo-substituented phenylalanine derivatives.

Key words: (S)-3,5-dibromophenylalanine, phase transfer catalyst, asymmetric catalytic hydrogenation, alkylation