Thiyl radical mediated racemization of benzylic amines
Thiyl radical mediated racemization of benzylic amines
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DOI：
10.1002/ejoc.200600120
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发表时间：
2006-07-10
影响因子：
2.8
通讯作者：
Bertrand, Michele P.
中科院分区：
文献类型：
--
作者：
Escoubet, Stephanie;Gastaldi, Stephane;Bertrand, Michele P.
硫基自由基介导的从立构中心α到氮原子的可逆H提取是使苄胺外消旋的温和方法。由于原子转移反应对焓效应的敏感性，了解 S-H 和 α-C-H 键解离能对于选择适合从给定胺中提取氢原子的硫醇至关重要。在缺乏实验数据的情况下，理论计算提供了有用的预测工具。这里描述的实验有助于描述外消旋化必须满足的最佳条件。在化学计量或催化量的硫醇存在下在合理的时间内进行。 (c) Wiley-VCH Verlag GmbH & Co.
Thiyl radical mediated reversible H abstraction from the stereogenic center alpha to the nitrogen atom is a mild method to racemize benzylic amines. Owing to the sensitivity of atom-transfer reactions to enthalpic effects, a knowledge of both the S-H and the alpha-C-H bond dissociation energies is fundamental to select the thiol that is appropriate to abstract the hydrogen atom from a given amine. In the absence of experi-mental data, theoretical calculations supply a useful predictive tool. The experiments described here are helpful in delineating the optimal conditions that have to be fulfilled for the racemization. to proceed in a reasonable time in the presence of either a stoichiometric or a catalytic amount of thiol. (c) Wiley-VCH Verlag GmbH & Co.