New Alkylidyne Complexes Featuring a Flexible Trianionic ONO<sup>3–</sup> Pincer-Type Ligand: Inorganic Enamine Effect versus Sterics in Electrophilic Additions
作者:Sudarsan VenkatRamani、Nicholas B. Huff、Muhammad Tariq Jan、Ion Ghiviriga、Khalil A. Abboud、Adam S. Veige
DOI:10.1021/acs.organomet.5b00155
日期:2015.6.22
Metal–carbon multiple bonds exhibit enhanced nucleophilicity at the α carbon within ONO trianionic pincer alkylidyne complexes. Defined as the inorganic enamine effect, this phenomenon is a result of the overlap of the N atom lone pair within the ONO3– ligand and a π bond from the metal–carbon multiple bond. Treating the proligand [OCH2NCH2O]H3 (2) with (tBuO)3W≡CR (where R = Et, tBu) results in the
金属-碳多重键在ONO三阴离子夹钳式亚烷基配合物中的α碳处表现出增强的亲核性。定义为无机烯胺效应,此现象是ONO 3–配体中N原子孤对和金属-碳多重键的π键重叠的结果。处理所述前配体〔O CH2 Ñ CH2 O] H ^ 3(2)与(吨迪布奥)3 W≡CR(其中R =的Et,吨丁基)导致形成双阴离子钳形络合物〔O CH 2 NH CH 2 O] w ^ ≡CR(O t Bu)(其中R = Et(3-Et),tBu(3- t Bu anti))。去质子化3-吨卜抗通过与pH处理3 P═CH 2形式的阴离子次烷基络合物〔O CH2 Ñ CH2 O]W≡C吨卜(O吨丁基)} CH 3 PPH 3 }(4-吨Bu)。建模4- t Bu的DFT计算揭示了具有W≡Cπ键的N个原子孤对的重叠。然而,与W≡C相反,4- t Bu与亲电子优先在N原子处发生反应α组。多核NMR光谱,燃烧分析,和单晶X射线