Guan Yiwen, Chang Kejian, Su Yujie, Xu Xian, Xu Xin
Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 215123, Suzhou, P. R. China.
Chem Asian J. 2024 May 17;19(10):e202400190. doi: 10.1002/asia.202400190. Epub 2024 Mar 27.
This work reports the cooperative reactivity of rare-earth aryloxide complexes with N-heterocyclic carbene (NHC) or N-heterocyclic olefin (NHO), showcasing their synergistic effect on the activation of H and diverse organic substrates. Reactions of RE(OAr) (RE=La, Sm, and Y; Ar=2,6-Bu-CH) with unsaturated NHC IBu (:C[N(R)CH], R=Bu) isolated abnormally bound RE metal NHC complexes RE/aNHC. In contrast, no metal-NHO adducts were formed when RE(OAr) were treated with NHO (RC=C[N(R)C(R)], R=CH). Both RE/aNHC and RE/NHO Lewis pairs enabled cooperative H activation. Furthermore, RE(OAr) were found to catalyze the hydrogenation of the exocyclic C=C double bond of NHO under mild conditions. Moreover, treatment of the La/aNHC complex with benzaldehyde produced a La/C4 1,2-addition product. The La/NHO Lewis pair could react with (trimethylsilyl)diazomethane and α, β-conjugated imine, affording an isocyanotrimethylsilyl lanthanum amide complex and a La/C 1,4-addition product, respectively.
本工作报道了稀土芳氧基配合物与氮杂环卡宾（NHC）或氮杂环烯烃（NHO）的协同反应活性，展示了它们对氢和多种有机底物活化的协同效应。RE(OAr)（RE = La、Sm和Y；Ar = 2,6-Bu-CH）与不饱和NHC IBu（:C[N(R)CH]，R = Bu）反应，分离得到异常键合的稀土金属NHC配合物RE/aNHC。相比之下，用NHO（RC=C[N(R)C(R)]，R = CH）处理RE(OAr)时未形成金属-NHO加合物。RE/aNHC和RE/NHO路易斯酸碱对均能实现协同氢活化。此外，发现RE(OAr)在温和条件下能催化NHO外环C=C双键的氢化反应。此外，用苯甲醛处理La/aNHC配合物得到一种La/C4 1,2-加成产物。La/NHO路易斯酸碱对可与（三甲基硅基）重氮甲烷和α,β-共轭亚胺反应，分别得到异氰基三甲基硅基镧酰胺配合物和一种La/C 1,4-加成产物。
