Product Inhibition in Nucleophilic Aromatic Substitution through DPPPent-Supported π-Arene Catalysis
Product Inhibition in Nucleophilic Aromatic Substitution through DPPPent-Supported π-Arene Catalysis
复制标题
通过 DPPPent 支持的 α-芳烃催化亲核芳香取代的产物抑制
DOI：
10.1039/d0dt00786b
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发表时间：
2020
影响因子：
4
通讯作者：
Schley, Nathan D.
中科院分区：
文献类型：
--
作者：
Mueller, Benjamin;Schley, Nathan D.
通过合成和表征中间体，研究了氟苯在双（二苯基膦基）戊烷负载的双烯亚胺配合物上的亲核芳族取代反应（SNAr）. SNAr步骤在室温下快速进行，然而产物N-苯基吗啉与钌离子紧密结合。在所研究的情况下，芳烃结合的热力学有利于产物N-苯基吗啉超过氟苯结合2000倍，对应于显著的产物抑制。催化剂静止状态的观察结果支持这一假设，并证明了先前提出的配体环化的添加剂控制的作用。
Nucleophilic aromatic substitution (SNAr) of fluorobenzene by morpholine at a bis(diphenylphosphino)pentane-supported ruthenim complex is investigated as a model system for π-arene catalysis through the synthesis and full characterization of proposed intermediates. The SNAr step proceeds quickly at room temperature, however the product N-phenylmorpholine binds tightly to the ruthenium ion. In the case examined, the thermodynamics of arene binding favor product N-phenylmorpholine over fluorobenzene binding by a factor of 2000, corresponding to significant product inhibition. Observations of the catalyst resting state support this hypothesis and demonstrate an additive-controlled role for a previously-proposed ligand cyclometalation.