1. Novel bidentate N-coordinated alkylaluminum complexes: synthesis, characterization, and efficient catalysis for hydrophosphonylation.
- Author
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Wei, Biao, Wang, Chaoqun, Miao, Hui, Qin, Zhibiao, Huang, Mengna, Xu, Yan, Xue, Wenhui, Yang, Shucheng, Liu, Chenxu, Bai, Cuibing, and Chen, Zheng
- Subjects
ALDIMINES ,CATALYSIS ,NUCLEAR magnetic resonance spectroscopy ,ELEMENTAL analysis ,IMINES ,CRYSTAL structure - Abstract
Five new alkylaluminum complexes with different pyridinyl-substituted imines or cyclohexyl-substituted imines were synthesized and characterized successfully. The aluminum complex [FlCHNCH(CH
3 )Py]AlMe2 (Py = 2-pyridyl) (1) was obtained by reacting 9-[2-pyridyl-CH(CH3 )-N=CH]Fl (Fl = fluorenyl) (L1 ) and equimolar AlMe3 . The reactions of 9-(2-pyridyl-N=CH)Fl (L2 ) and 9-[2-N(CH3 )2 -cyclohexyl-N=CH]Fl (L3 ) with equimolar AlMe3 or AlEt3 afforded other alkylaluminum complexes [FlCHNPy]AlMe2 (Py = 2-pyridyl) (2), [FlCHNPy]AlEt2 (Py = 2-pyridyl) (3), [FlCHNCyN(CH3 )2 ]AlMe2 (Cy = 2-cyclohexyl) (4) and [FlCHNCyN(CH3 )2 ]AlEt2 (Cy = 2-cyclohexyl) (5). All these complexes (1–5) were characterized using NMR spectroscopy, elemental analysis, and X-ray crystal structure analysis. The catalytic properties of these new alkylaluminum complexes for the hydrophosphonylation of aldimines were examined. Complex 5 showed the best catalytic performance under mild reaction conditions with a low catalyst loading (1 mol%), and 20 different substituents of aldimines were isolated with more than 90% yields. [ABSTRACT FROM AUTHOR]- Published
- 2024
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