The peculiar electronic structure of scandium phosphinoalkylidene complex [LSc{C（SiMe3）PPh2}THF] （L=[MeC（NDIPP）CHC（NDIPP）Me]-）, DIPP= 2,6-（Pr）2C6H3） leads to an interesting versatile reactivity, which is de...The peculiar electronic structure of scandium phosphinoalkylidene complex [LSc{C（SiMe3）PPh2}THF] （L=[MeC（NDIPP）CHC（NDIPP）Me]-）, DIPP= 2,6-（Pr）2C6H3） leads to an interesting versatile reactivity, which is demonstrated both experimentally and computationally. The complex undergoes [2＋2] cycloaddition reactions with alkynes, and easily activates various X-O bonds such as C-O of propylene oxide, N-O of 3,5-dimethylisoxazole, B-O of pinacolborane and Si-O of triethoxysilane. These reactions occur on the Sc-C bond of the phosphinoalkylidene complex. Interestingly, the Sc-P bond can also be activated as the presence of a Sc-C-P three center π interaction in the complex allows performing C-F activation of 2,6-difluoro- pyridine and 1,2 addition with imine or ketone. The complex also reacts with metal complexes, [（COD）RhCl]2 and （Ph3P）AuCl, to form structural intriguing heterobimetallic complexes.展开更多
The mechanism of cycloaddition reaction between singlet alkylidene carbene and ethylene has been investigated with second-order Moller-Plesset perturbation theory (MP2). By using 6–31G* basis, geometry optimization, ...The mechanism of cycloaddition reaction between singlet alkylidene carbene and ethylene has been investigated with second-order Moller-Plesset perturbation theory (MP2). By using 6–31G* basis, geometry optimization, vibrational analysis and energetics have been calculated for the involved stationary points on the potential energy surface. The results show that the title reaction has two major competition channels. An energy-rich intermediate (INT) is firstly formed between alkylidene carbene and ethylene through a barrier-free exothermic reaction of 63.62 kJ/mol, and the intermediate then isomerizes to a three-membered ring product (Pl) and a four-membered ring product (P2) via transition state TS1 and TS2, in which energy barriers are 47.00 and 51.02 kl/mol. respectively. PI is the main product.展开更多
基金This work was supported by the National Natural Science Foundation of China （Nos. 21732007 and 21325210）, the Strategic Priority Research Program of the Chinese Academy of Sciences {Grant No. XDB20000000）, and the Program of Shanghai Academ- ic Research Leader. LM is a member of the Institut Universitaire de France. LM acknowledges Humboldt foundation and the Chinese Scholarship Council.
文摘The peculiar electronic structure of scandium phosphinoalkylidene complex [LSc{C（SiMe3）PPh2}THF] （L=[MeC（NDIPP）CHC（NDIPP）Me]-）, DIPP= 2,6-（Pr）2C6H3） leads to an interesting versatile reactivity, which is demonstrated both experimentally and computationally. The complex undergoes [2＋2] cycloaddition reactions with alkynes, and easily activates various X-O bonds such as C-O of propylene oxide, N-O of 3,5-dimethylisoxazole, B-O of pinacolborane and Si-O of triethoxysilane. These reactions occur on the Sc-C bond of the phosphinoalkylidene complex. Interestingly, the Sc-P bond can also be activated as the presence of a Sc-C-P three center π interaction in the complex allows performing C-F activation of 2,6-difluoro- pyridine and 1,2 addition with imine or ketone. The complex also reacts with metal complexes, [（COD）RhCl]2 and （Ph3P）AuCl, to form structural intriguing heterobimetallic complexes.
基金the Natural Science Foundation of Shandong Province of China (No. Y2002B07).
文摘The mechanism of cycloaddition reaction between singlet alkylidene carbene and ethylene has been investigated with second-order Moller-Plesset perturbation theory (MP2). By using 6–31G* basis, geometry optimization, vibrational analysis and energetics have been calculated for the involved stationary points on the potential energy surface. The results show that the title reaction has two major competition channels. An energy-rich intermediate (INT) is firstly formed between alkylidene carbene and ethylene through a barrier-free exothermic reaction of 63.62 kJ/mol, and the intermediate then isomerizes to a three-membered ring product (Pl) and a four-membered ring product (P2) via transition state TS1 and TS2, in which energy barriers are 47.00 and 51.02 kl/mol. respectively. PI is the main product.
