Progressing the Frustrated Lewis Pair Abilities of N-Heterocyclic Carbene/GaR<sub>3</sub> Combinations for Catalytic Hydroboration of Aldehydes and Ketones
作者:Leonie J. Bole、Marina Uzelac、Alberto Hernán-Gómez、Alan R. Kennedy、Charles T. O’Hara、Eva Hevia
DOI:10.1021/acs.inorgchem.1c01276
日期:2021.9.20
comparative study of the catalytic capabilities of several gallium and borenium species related to 2. Disclosing a new cooperative partnership, reactions are proposed to occur via the formation of a highly reactive monomeric hydride gallate, [ItBu-BPin}+GaR3(H)}−] (I). Each anionic and cationic component of I plays a key role for success of the hydroboration, with the nucleophilic monomeric gallate anion
利用三(烷基)镓GaR 3 (R = CH 2 SiMe 3 )和庞大的N-杂环卡宾(NHC) 1,3-双(叔丁基)咪唑-2-亚基(I t Bu ),在这里我们报告频哪醇硼烷 (HBPin) 的 B-H 键活化,这导致了新离子对的分离和结构验证,[I t Bu-BPin} + GaR 3 (μ-H)GaR 3 } - ] ( 2 )。相比之下,在本研究的条件下,I t Bu 或 GaR 3均不能与 HBPin 反应。结合 NHC 稳定的硼阳离子,[It Bu-BPin} + ],带有阴离子双核镓酸盐,[GaR 3 (μ-H)GaR 3 } - ], 2证明在室温下在溶液中不稳定,演变为异常的 NHC-Ga 复合物 [BPinC N( t Bu)] 2 CHCGa(R) 3 }] ( 3 )。有趣的是,获得了2的结构异构体,硼阳离子位于卡宾的 C4 位置,[ a I t Bu-BPin}