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Two equivalents of the thermally stable silylene Si[(NCH2But)2C6H4-1,2] (1) react with pyridine to yield the 1-aza-2,3-disilacyclobutane derivative (2), which is labile and slowly rearranges via a 1,3-H shift to the 2-pyridyldisilane (3). A similar reaction of 1 with quinoline gives 1-aza-2,3-disilacyclobutane derivative (4), which is stable. The X-ray structures of 2 and 3 are discussed. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(13):3753-3756
The first single‐component N‐heterocyclic silylene borane 1 (LSi‐R‐BMes2; L=PhC(Nt Bu)2; R=1,12‐xanthendiyl spacer; Mes=2,4,6‐Me3C6H2), acting as a frustrated Lewis pair (FLP) in small‐molecule activation, can be synthesized in 65 % yields. Its HOMO is largely localized at the silicon(II) atom and the LUMO has mainly boron 2p character. In small‐molecule activation 1 allows access to the intramolecular silanone–borane 3 featuring a Si=O→B interaction through reaction with O2, N2O, or CO2, and formation of silanethione borane 4 from reaction with S8. The SiII center in 1 undergoes immediate hydrogenation if exposed to H2 at 1 atm pressure in benzene, affording the silane borane 5‐H2 , L(H2)Si‐R‐BMes2. Remarkably, no H2 activation occurs if the single silylene LSiPh and Mes3B intermolecularly separated are exposed to dihydrogen. Unexpectedly, the pre‐organized Si–B separation in 1 enables a metal‐free dehydrogenation of H2O to give the silanone–borane 3 as reactive intermediate. 相似文献
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An overview of the development of compounds with heavier low-valent group 14 elements (known as tetrylenes) as single component catalyst for organic transformation has been provided. Compounds with heavier group 14 elements possess stereochemically active lone pairs and energetically accessible π-antibonding orbitals, thereby resembling the electronic configuration of transition-metal compounds. Such compounds with low-valent group 14 elements has been known for small molecule activation since Power's report of dihydrogen activation by a digermyne, but their utilization in catalysis remained as a “Holy Grail” in main group chemistry. In recent years, numerous methodologies have been discovered epitomizing the use of Si(II), Ge(II) and Sn(II) compounds as single site catalysts for hydroboration of aldehydes, ketones, pyridines, cyanosilylation of aldehydes and ketones, N-formylations aromatic amines, dehydrocoupling reactions. This mini-review highlights these significant developments with an emphasis on the mechanistic investigation. 相似文献
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Thermolysis of 2,3-benzo-1,4-diphenyl-7-silanorbornadiene derivatives 1 in the presence of 2,3-dimethylbutadienes gave the trapping products of the corresponding bissilylene, disilenylsilylene, and a tetrasila-1,3-butadiene, via a consecutive disilanylsilylene to silyldisilene rearrangement. 相似文献
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Barbara Gehrhus Peter B. Hitchcock Helen Jansen 《Journal of organometallic chemistry》2006,691(4):811-816
Reaction of the thermally stable silylene Si[(NCH2But)2C6H4-1,2] (1) [abbrev. as Si(NN)] with SiX4 (X = Cl or Br) afforded the disilanes (NN)SiX(SiX3) and [(NN)SiX]2 (X = Br only), the trisilane (NN)SiX-[(SiX3)Si(NN)] and the monosilane (NN)SiX2 (X = Br only), whereas treatment of 1 with MCl4 (M = Ge or Sn) yielded (NN)SiCl2 and MCl2. [(NN)SiBr]2 and (NN)SiBr2 were also obtained by reaction of 1 with Br2. Reaction of 1 with PhSiCl3 yielded the disilane (NN)SiCl(SiCl2Ph) and trisilane [(NN)SiCl]2SiClPh, whereas the disilane (NN)SiCl(SiCl2Me) was obtained with MeSiCl3. The trisilane (NN)SiCl-[(SiCl3)Si(NN)] was thermally labile and converted to [(NN)SiCl]2SiCl2. 相似文献
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