Synthesis of rare-earth metal bisalkyl complexes supported by [1-(2-N-morpholinoethylene)-3-(4,4-dimethyl-2-oxazolinyl)] indolyl ligand and their application in the intermolecular hydrophosphination of aryl alkenes

• Published in: Inorganica Chimica Acta 2022-11, Vol.542, p.121096, Article 121096
• Main Authors: Wang, Xiangrui, Ji, Xian, Zhao, Xu, Huang, Zeming, Huang, Jiangsheng, Wang, Fenhua, Yan, Bohan, Chu, Chenghao, Wang, Shaowu
• Format: Article
• Language: English
• Subjects: Alkyl complexes; Functionalized indolyl ligand; Hydrophosphination; Rare-earth metal
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2022.121096

[Display omitted] •A series of N-protected 3-oxazolinyl functionalized indolyl rare-earth metal complexes were developed and formed RE-C bond by 2-indolyl CH activation.•Complexes performed high catalytic activities and exclusive regiospecificity in intermolecular hydrophosphination of bulky alkenes.•The catalytic mechanism was proposed according to the 1H NMR and 31P NMR spectra. Well-defined N-protected 3‑oxazolinyl functionalized indolyl rare-earth metal bisalkyl complexes LRE(CH2SiMe3)2(DME), (L = 1-(2-N-morpholinoethylene)-3-(4,4-dimethyl-2-oxazolinyl) indolyl, RE = Y (1a), Yb (1b), Er (1c), Dy (1d), Gd (1e), DME = 1,2-dimethoxyethane) have been synthesized and characterized. The complexes were coordinated by the 2‑indolyl sp2 carbanion, N atom of oxazolinyl, two alkyl groups and two oxygen atoms of DME. They performed high catalytic activities in the intermolecular hydrophosphination of various styrene derivatives and demonstrated exclusive regiospecificity affording the anti-Markovnikov addition products. The catalysts could promote hydrophosphination of bulky alkenes such as naphthalene ethylene under relatively mild conditions.