An Isolable Mononuclear Palladium(I) Amido Complex
An Isolable Mononuclear Palladium(I) Amido Complex
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DOI：
10.1021/jacs.1c04965
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发表时间：
2021-07-07
影响因子：
15
通讯作者：
Deng, Liang
中科院分区：
文献类型：
--
作者：
Liu, Jian;Bollmeyer, Melissa M.;Deng, Liang
单核Pd(I)物种是Pd催化反应中可能的中间体，但由于获取它们的困难，我们对它们的了解有限。在这里，我们报道了从(BINAP)PdCl2与LiNHArTrip的反应中分离得到一个Pd(I)氨基配合物[(BINAP)Pd(NHArTrip)](BINAP=2，2‘-bis(diphenylphosphino)-1，1’-binaphthalene，Ar-Trip=2，6-双(2‘，4’，6‘-三异丙基苯基)苯基)。用X-射线结晶学、电子顺磁共振和多边Pd-X-射线吸收光谱对该Pd(I)-氨基物种进行了表征。理论研究表明，虽然Pd(I)络合物中Pd和N之间的三电子-双中心pi-相互作用对其Pd-N键产生严重的Pauli排斥，但显著的吸引配体间的色散力有助于其稳定。与其电子性质相一致，在Pd(I)-氨基络合物上观察到均相裂解Pd-N键和伯胺去质子化反应。
Mononuclear Pd(I) species are putative intermediates in Pd-catalyzed reactions, but our knowledge about them is limited due to difficulties in accessing them. Herein, we report the isolation of a Pd(I) amido complex, [(BINAP)Pd(NHArTrip)] (BINAP = 2,2'-bis(diphenylphosphino)-1,1'-binaphthalene, Ar-Trip = 2,6-bis(2',4',6'-triisopropylphenyl)phenyl), from the reaction of (BINAP)PdCl2 with LiNHArTrip. This Pd(I) amido species has been characterized by X-ray crystallography, electron paramagnetic resonance, and multiedge Pd X-ray absorption spectroscopy. Theoretical study revealed that, while the three-electron-two-center pi-interaction between Pd and N in the Pd(I) complex imposes severe Pauli repulsion in its Pd-N bond, pronounced attractive interligand dispersion force aids its stabilization. In accord with its electronic features, reactions of homolytic Pd-N bond cleavage and deprotonation of primary amines are observed on the Pd(I) amido complex.