Computational Exploration of Dirhodium Complex-Catalyzed Selective Intermolecular Amination of Tertiary vs. Benzylic C-H Bonds.
Computational Exploration of Dirhodium Complex-Catalyzed Selective Intermolecular Amination of Tertiary vs. Benzylic C-H Bonds.
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DOI：
10.3390/molecules28041928
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发表时间：
2023-02-17
期刊：
影响因子：
4.6
通讯作者：
Yang, Yun-Fang
中科院分区：
文献类型：
--
作者：
Su, Xing-Xing;Chen, Xia-He;Ding, De-Bo;She, Yuan-Bin;Yang, Yun-Fang
利用密度泛函理论 (DFT) 计算研究了 Rh2(S-tfpttl)4 催化的 C(sp3)-H 键胺化反应的位点选择性机制和起源。二铑配合物 Rh2(S-tfpttl)4 与叔丁基苯酚氨基磺酸盐 TBPhsNH2 的协同组合构成了一个可以连接叔键和苄基 C-H 键的口袋。在电子活化的苄基 C-H 键存在下，未活化的叔 C-H 键被选择性胺化。本研究对单线态和三线态能量面进行了研究。计算结果表明三重态逐步路径比单重态协同路径更有利。在Rh-氮宾夺取氢原子的过程中，这是速率和位点选择性的决定步骤，在三级C-H活化过渡结构中，底物的苯基和配体的邻苯二甲酰亚胺基之间存在有吸引力的π-π堆积相互作用。相比之下，苄基 C-H 胺化过渡结构中不存在这种吸引相互作用。因此，DFT计算结果清楚地证明了二铑配合物与氨基磺酸盐的协同组合如何超越对苄基C-H胺化的内在偏好，以实现未活化的叔C-H键的胺化。
The mechanism and origins of site-selectivity of Rh2(S-tfpttl)4-catalyzed C(sp3)–H bond aminations were studied using density functional theory (DFT) calculations. The synergistic combination of the dirhodium complex Rh2(S-tfpttl)4 with tert-butylphenol sulfamate TBPhsNH2 composes a pocket that can access both tertiary and benzylic C–H bonds. The nonactivated tertiary C–H bond was selectively aminated in the presence of an electronically activated benzylic C–H bond. Both singlet and triplet energy surfaces were investigated in this study. The computational results suggest that the triplet stepwise pathway is more favorable than the singlet concerted pathway. In the hydrogen atom abstraction by Rh–nitrene species, which is the rate- and site-selectivity-determining step, there is an attractive π–π stacking interaction between the phenyl group of the substrate and the phthalimido group of the ligand in the tertiary C–H activation transition structure. By contrast, such attractive interaction is absent in the benzylic C–H amination transition structure. Therefore, the DFT computational results clearly demonstrate how the synergistic combination of the dirhodium complex with sulfamate overrides the intrinsic preference for benzylic C–H amination to achieve the amination of the nonactivated tertiary C–H bond.
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影响因子：
15
作者：
DeAngelis, Andrew;Dmitrenko, Olga;Fox, Joseph M.
通讯作者：
Fox, Joseph M.
影响因子：
15
作者：
Fleming, JJ;Du Bois, J
通讯作者：
Du Bois, J
影响因子：
15
作者：
Espino, CG;Fiori, KW;Du Bois, J
通讯作者：
Du Bois, J
影响因子：
15
作者：
Hinman, A;Du Bois, J
通讯作者：
Du Bois, J
影响因子：
4.4
作者：
DITCHFIELD, R;HEHRE, WJ;POPLE, JA
通讯作者：
POPLE, JA