Addition of bulky primary silanes to the osmium benzyl compound, Cp*(iPr3P)OsCH2Ph, afforded two neutral hydrogen-substituted silylene complexes via activation of two Si-H bonds. These species have been structurally characterized, and their reactivity has been examined experimentally and computationally. Comparison of these neutral silylene complexes with their cationic analogue highlights the dramatic influence of charge distribution on the reaction chemistry of metal silylene complexes.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/ja057494q | DOI Listing |
Dalton Trans
December 2024
Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
Effective activation of small molecules (alcohol, phenol, ketones, amine, .) by a hydrogen-bridged bis(silylene) complex, which has two adjacent Lewis acidic centers and a hydridic bridging hydrogen with weak Si⋯H bonds, is described, along with product characterization by NMR and X-ray diffraction studies.
View Article and Find Full Text PDFChemistry
December 2024
Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai, 980-8578, Japan.
Reactions of cyclic thioureas (1,3,4,5-tetramethylimidazol-2-thione and 1,3-dimethylimidazolidin-2-thione) and ureas (1,3,4,5-tetramethylimidazol-2-one and 1,3-dimethylimidazolidin-2-one) with an isolable dialkylsilylene were examined. In these reactions, cyclic thioureas served as sulfur and NHC (N-heterocyclic carbene) sources, and the corresponding silanethione and NHC-derived products formed via silanethione-NHC complexes. Reactions of cyclic ureas with the silylene afforded a new NHC and an isolable azomethine ylide.
View Article and Find Full Text PDFChem Asian J
October 2024
Department of Chemistry, Indian Institute of Science Education and Research Pune, Dr. Homi Bhabha Road, Pashan, Pune, 411008, India.
We have explored NHSi-supported copper(I) complexes as active and highly efficient catalysts for A (aldehyde-alkyne-amine) and KA (ketone-alkyne-amine) three-component coupling reactions to synthesize propargyl amines in excellent yields with high TOF under solvent-and additive-free conditions.
View Article and Find Full Text PDFJ Am Chem Soc
November 2024
Molecular Inorganic Chemistry and Catalysis, Inorganic and Structural Chemistry, Center for Molecular Materials, Faculty of Chemistry, Universität Bielefeld, Universitätsstrasse 25, D-33615 Bielefeld, Germany.
The isolation of silicon analogues of phenyl anions such as (CH) and (CH) is challenging owing to their extremely high reactivity associated with their silylene character and weak C-Si π-interaction. Herein, we report the first annulated 1,4-disilabenzene-1,4-diide compound [(ADC)Si] () based on anionic dicarbene (ADC) scaffolds (ADC = PhC{N(Dipp)C}; Dipp = 2,6-PrCH) as a green-yellow crystalline solid. Compound is prepared by KC reduction of the Si(IV) chloride [(ADC)SiCl] () or the cyclic bis-chlorosilylene [(ADC)SiCl] (), which are also prepared for the first time.
View Article and Find Full Text PDFChem Commun (Camb)
November 2024
TUM School of Natural Sciences, Department of Chemistry, Catalysis Research Center and Wacker-Institute of Silicon Chemsitry, Technische Universität München (TUM), Lichtenbergstrasse 4, 85748 Garching bei München, Germany.
Herein, we report the reactivity of N-heterocyclic carbene stabilized silylene-phosphinidene IDippPSi(TMS)SiTol (IDipp = 1,3-bis(2,6-diisopropylphenyl)-imidazolin-2-ylidene) with ammonia, which results in an intermolecular 1,5-hydroamination and dearomatization of the NHC wingtip. DFT calculations reveal an unprecedented mechanism involving ammonia coordination to the silicon center, Meisenheimer-type complex formation, and a proton abstraction by the dearomatized aryl moiety.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!