Hydroaminoalkylation of unactivated olefins with dialkylamines.
Hydroaminoalkylation of unactivated olefins with dialkylamines.
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DOI：
10.1021/ja806367e
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发表时间：
2008-11-12
影响因子：
15
通讯作者：
Hartwig JF
中科院分区：
文献类型：
--
作者：
Herzon SB;Hartwig JF
本文报道了在氯代酰胺配合物[TaCl_3（NEt_2）_2]_2（2）存在下，未活化的二烷基胺与烯烃的α-C-H键的分子间加成反应。该方法以高产率（高达96%）和选择性形成支链插入产物，并且代表了不需要预活化任一底物的分子间胺-烯烃偶联反应的罕见实例。所示的反应，以涵盖添加的线性和支链的甲胺，以及仲C-H键。相关的氯代苯胺基络合物[TaCl 3（NMePh）2]2（4）也显示出在低至90 °C的温度下催化N烷基-芳基胺与烯烃的加成。1H NMR光谱、催化剂结构的鉴定和氘标记实验都表明，由2和4催化的反应通过η2-亚胺络合物的转换限制生成而发生，η2-亚胺络合物是转换限制的，并且通过胺的消除而发生。这些标记研究还暗示，相对于起始双酰胺基络合物的再生，η2-亚胺络合物朝向与烯烃的反应的更有利的分配解释了混合卤化物酰胺基催化剂相对于均配酰胺基络合物的更高的反应性。
The intermolecular addition of the α-C–H bonds of unactivated dialkylamines to olefins in the presence of the chloro amido complex [TaCl3(NEt2)2]2 (2) is described. This process forms the branched insertion products in high yields (up to 96%) and selectivities, and represents a rare example of an intermolecular amine-olefin coupling reaction that does not require pre-activation of either substrate. The reaction is shown to encompass the addition of linear- and branched-methylamines, as well as secondary C–H bonds. The related chloroanilido complex [TaCl3(NMePh)2]2 (4) is also shown to catalyze the addition of Nalkyl-arylamines to olefins at temperatures as low as 90 °C. 1H NMR spectroscopy, identification of the catalyst structure, and deuterium-labeling experiments all suggest that reactions catalyzed by 2 and 4 occur by turnover-limiting generation of an η2- imine complex is turnover-limiting and occurs by elimination of amine. These labeling studies also imply that more favorable partitioning of the η2-imine complex toward reaction with alkene versus regeneration of the starting bis-amido complex accounts for the higher reactivity of the mixed halide amido catalyst versus a homoleptic amido complex.