Asymmetric radical cyclization reactions of axially chiral N-allyl-o-iodoanilides to form enantioenriched N-acyl dihydroindoles
Asymmetric radical cyclization reactions of axially chiral N-allyl-o-iodoanilides to form enantioenriched N-acyl dihydroindoles
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DOI：
10.1016/j.tet.2004.02.064
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发表时间：
2004-05-10
期刊：
影响因子：
2.1
通讯作者：
Lapierre, AJB
中科院分区：
文献类型：
--
作者：
Curran, DP;Chen, CHT;Lapierre, AJB
对映体富集的N-烯丙基-O-碘代苯胺的自由基环化以良好的产率提供N-酰基-3-烷基-2，3-二氢吲哚，并且具有从N-Ar轴到新的立构中心的良好至优异水平的手性转移。在N-丙烯酰基-N-烯丙基-邻碘酰苯胺的竞争性环化反应中，邻甲基的加入逆转了从丙烯酰基到烯丙基的自由基环化的区域选择性。代表性的自由基环化的近似速率常数已被测量，以提供洞察这些观察的起源。(C)2004爱思唯尔有限公司保留所有权利。
Radical cyclizations of enantiomerically enriched N-allyl-o-iodoanilides provide N-acyl-3-alkyl-2,3-dihydroindoles in good yields and with good to excellent levels of chirality transfer from the N-Ar axis to the new stereocenter. In competitive cyclizations of N-acryloyl-N-allyl-o-iodoanilides, the addition of an o-methyl group reverses the regioselectivity of the radical cyclization from the acryloyl group to the allyl group. Approximate rate constants for representative radical cyclizations have been measured to provide insight into the origin of these observations. (C) 2004 Elsevier Ltd. All rights reserved.