- Selective homo- And cross-desilacoupling of aryl and benzyl primary silanes catalyzed by a barium complex
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Under mild conditions (25 °C, 5 mol% cat.), highly selective homo- and cross-desilacoupling of aryl and benzyl primary silanes to secondary silanes was achieved by the use of the heteroleptic barium aminobenzyl complex [(TpAd,iPr)Ba(CH2C6H4NMe2-o)] (TpAd,iPr = hydrotris(3-adamantyl-5-isopropyl-pyrazolyl)borate) (1) as a catalyst. Dihydrosilanes originating from catalytic redistribution and cross-desilacoupling reactions were isolated in fine yields, which demonstrates the feasible application of the barium complex in the syntheses of secondary aryl- and benzylsilanes. This journal is
- Cheng, Jianhua,Liu, Zhizhou,Shi, Xianghui
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p. 8340 - 8346
(2020/07/07)
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- Divalent Ytterbium Complex-Catalyzed Homo- and Cross-Coupling of Primary Arylsilanes
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Redistribution of primary silanes through C-Si and Si-H bond cleavage and reformation provides a straightforward synthesis of secondary silanes, but the poor selectivity and low efficiency severely hinders the application of this synthetic protocol. Here, we show that a newly synthesized divalent ytterbium alkyl complex exhibits unprecedentedly high catalytic activity toward the selective redistribution of primary arylsilanes to secondary arylsilanes. More significantly, this complex also effectively catalyzes the cross-coupling between electron-withdrawing substituted primary arylsilanes and electron-donating substituted primary arylsilanes to secondary arylsilanes containing two different aryls. DFT calculation indicates that the reaction always involve the exothermic formation of a hypervalent silicon upon facile addition of PhSiH3 to the Yb-E (E = C, H) bond. This hypervalent compound can easily either generate directly the Yb-Ph complex, or indirectly through the formation of Yb-H, that is the key complex for the formation of Ph2SiH2.
- Liu, Xiaojuan,Xiang, Li,Louyriac, Elisa,Maron, Laurent,Leng, Xuebing,Chen, Yaofeng
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supporting information
p. 138 - 142
(2019/01/16)
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- Highly selective redistribution of primary arylsilanes to secondary arylsilanes catalyzed by Ln(CH2C6H4NMe2-: O)3@SBA-15
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Rare-earth metal tris(aminobenzyl) complexes Ln(CH2C6H4NMe2-o)3 (Ln = La, Y) were grafted onto the dehydroxylated periodic mesoporous silica support SBA-15 to generate the organometallic-inorganic hybrid materials Ln(CH2C6H4NMe2-o)3@SBA-15 (Ln = La (2a), Y (2b)), which demonstrated extremely high selectivity (>99%) in catalyzing the redistribution of primary arylsilanes to secondary arylsilanes without the requisition of strict control of the reaction conditions. The hybrid materials still showed a perfect selectivity and activity after three catalytic cycles.
- Guo, Chenjun,Li, Min,Chen, Jue,Luo, Yunjie
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supporting information
p. 117 - 120
(2019/12/25)
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