Trapping a Silicon(I) Radical with Carbenes: A Cationic cAAC-Silicon(I) Radical and an NHC-Parent-Silyliumylidene Cation
| Autor: | Pattiyil Parameswaran, Indu Purushothaman, Yan Li, Yongxin Li, Bi-Xiang Leong, Yuk-Chi Chan, Cheuk-Wai So, Emma Richards, Susmita De |
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| Rok vydání: | 2017 |
| Předmět: |
chemistry.chemical_classification
Reaction mechanism 010405 organic chemistry Dimer Fluorobenzene Cationic polymerization General Medicine General Chemistry Nuclear magnetic resonance spectroscopy 010402 general chemistry Photochemistry 01 natural sciences Medicinal chemistry Catalysis 0104 chemical sciences law.invention chemistry.chemical_compound chemistry law Electron paramagnetic resonance Carbene Alkyl |
| Zdroj: | Angewandte Chemie International Edition. 56:7573-7578 |
| ISSN: | 1433-7851 |
| DOI: | 10.1002/anie.201702760 |
| Popis: | The trapping of a silicon(I) radical with N-heterocyclic carbenes is described. The reaction of the cyclic (alkyl)(amino) carbene [cAACMe] (cAACMe=:C(CMe2)2(CH2)NAr, Ar=2,6-iPr2C6H3) with H2SiI2 in a 3:1 molar ratio in DME afforded a mixture of the separated ion pair [(cAACMe)2Si:.]+I− (1), which features a cationic cAAC–silicon(I) radical, and [cAACMe−H]+I−. In addition, the reaction of the NHC–iodosilicon(I) dimer [IAr(I)Si:]2 (IAr=:C{N(Ar)CH}2) with 4 equiv of IMe (:C{N(Me)CMe}2), which proceeded through the formation of a silicon(I) radical intermediate, afforded [(IMe)2SiH]+I− (2) comprising the first NHC–parent-silyliumylidene cation. Its further reaction with fluorobenzene afforded the CAr−H bond activation product [1-F-2-IMe-C6H4]+I− (3). The isolation of 2 and 3 confirmed the reaction mechanism for the formation of 1. Compounds 1–3 were analyzed by EPR and NMR spectroscopy, DFT calculations, and X-ray crystallography. |
| Databáze: | OpenAIRE |
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