A general method for the asymmetric synthesis of both enantiomers of 1-substituted 1,2,3,4-tetrahydro-β-carbolines employing pyroglutamic acid derivatives as chiral auxiliaries
A general method for the asymmetric synthesis of both enantiomers of 1-substituted 1,2,3,4-tetrahydro-β-carbolines employing pyroglutamic acid derivatives as chiral auxiliaries
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DOI：
10.1016/s0040-4020(03)00420-4
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发表时间：
2003-05-05
期刊：
影响因子：
2.1
通讯作者：
Ohsawa, A
中科院分区：
文献类型：
--
作者：
Itoh, T;Miyazaki, M;Ohsawa, A
在2，2，2-三氯乙基氯甲酸酯存在下，9-（S）-吡咯烷胺基-β-咔啉与亲核试剂（烯丙基三丁基锡或烯醇醚硅）反应，以良好的产率和高的非对映选择性得到1，2-加成产物。N-9处的手性助剂容易通过温和水解除去。相同的手性源通过简单地改变酰胺氮的保护基得到两种对映异构体。也就是说，具有N-烷基的（S）-焦亚氨酰基得到（S）异构体，而具有N-酰基的焦亚氨酰基产生加成产物的（R）异构体。(C)2003爱思唯尔科技有限公司版权所有。
9-(S)-Pyroglutaminyl-beta-carbolines were allowed to react with a nucleophile (allyltributyltin or a silyl enol ether) in the presence of 2,2,2-trichloroethyl chloroformate to give 1,2-addition products in good yields and high diastereoselectivity. The chiral auxiliary at N-9 was readily removed by a mild hydrolysis. The same chiral source afforded both enantiomers by simply altering a protecting group of the amide nitrogen. That is, (S)-pyroglutaminyl groups which had an N-alkyl group afforded the (S) isomer, whereas the ones having an N-acyl group produced the (R) isomer of the addition products. (C) 2003 Elsevier Science Ltd. All rights reserved.