Catalytic C-H amination of alkanes with sulfonimidamides: silver(I)-scorpionates vs. dirhodium(II) carboxylates
Catalytic C-H amination of alkanes with sulfonimidamides: silver(I)-scorpionates vs. dirhodium(II) carboxylates
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DOI：
10.1016/j.tet.2013.02.005
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发表时间：
2013-06-03
期刊：
影响因子：
2.1
通讯作者：
Dauban, Philippe
中科院分区：
文献类型：
--
作者：
Beltran, Alvaro;Lescot, Camille;Dauban, Philippe
银配合物[Tp*Ag-，Ag-Br]（2）（Tp*（，Br）：氢化三（4-溴-3，5-二甲基）吡唑硼酸酯）和铑配合物Rh-2（S-nta）（4）（nta：N-（1，8-萘甲酰基）-丙氨酸）是通过氮烯插入进行C-H键官能化的合适催化剂。这两种配合物显示类似的催化活性的苄基C-H键的官能化，虽然银衍生物不提供非常高的非对映选择诱导的铑配合物。另一方面，当从5当量的烷烃如戊烷和其它C-6-C-8支链非活化烃开始时，是银催化剂促进C-H键的胺化，产率高达70%，高于铑对应物提供的产率。当可用时，底物的叔C-H键优先衍生化，这是涉及碳中心自由基的逐步机制的结果。(C)2013爱思唯尔有限公司保留所有权利。
The silver complex [Tp*Ag-,Ag-Br](2) (Tp*(,Br): hydrotris(4-bromo-3,5-dimethyl)pyrazolyl borate) and the rhodium complex Rh-2(S-nta)(4) (nta: N-(1,8-naphthoyl)-alanine) are competent catalysts for C-H bond functionalization by nitrene insertion. Both complexes display similar catalytic activity for the functionalization of benzylic C-H bonds, although the silver derivative does not provide the very high diastereoselection induced by the rhodium complex. On the other hand, when starting from 5 equiv of alkanes, such as pentane and other C-6-C-8 branched non-activated hydrocarbons, it is the silver catalyst that promotes the amination of the C-H bonds with yields of up to 70%, higher than those provided by the rhodium counterpart. When available, the tertiary C-H bonds of the substrate are preferentially derivatized, as a consequence of a stepwise mechanism in which carbon-centered radicals are involved. (C) 2013 Elsevier Ltd. All rights reserved.