State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , 345 Lingling Road, Shanghai 200032, P. R. China.
LPCNO, CNRS & INSA, Université Paul Sabatier , 135 Avenue de Rangueil, 31077 Toulouse, France.
J Am Chem Soc. 2017 Jan 25;139(3):1081-1084. doi: 10.1021/jacs.6b13081. Epub 2017 Jan 12.
The first scandium phosphinoalkylidene complex was synthesized and structurally characterized. The complex has the shortest Sc-C bond lengths reported to date (2.089(3) Å). DFT calculations reveal the presence of a three center π interaction in the complex. This scandium phosphinoalkylidene complex undergoes intermolecular C-H bond activation of pyridine, 4-dimethylamino pyridine and 1,3-dimethylpyrazole at room temperature. Furthermore, the complex rapidly activates H under mild conditions. DFT calculations also demonstrate that the C-H activation of 1,3-dimethylpyrazole is selective for thermodynamic reasons and the relatively slow reaction is due to the need of fully breaking the chelating effect of the phosphino group to undergo the reaction whereas this is not the case for H.
首例钪膦亚烷基配合物被合成并进行了结构表征。该配合物具有迄今为止报道的最短 Sc-C 键长（2.089(3) Å）。DFT 计算表明，该配合物中存在三中心π相互作用。该钪膦亚烷基配合物在室温下可实现吡啶、4-二甲氨基吡啶和 1,3-二甲基吡唑的分子间 C-H 键活化。此外，该配合物可在温和条件下迅速活化 H。DFT 计算还表明，1,3-二甲基吡唑的 C-H 活化是出于热力学原因具有选择性的，相对缓慢的反应是由于需要完全打破膦基的螯合效应才能进行反应，而对于 H 则不是这种情况。
