Direct Catalytic Access to N-Silylated Enamines from Enolizable Imines and Hydrosilanes by Base-Free Dehydrogenative SiN Coupling
作者:Julia Hermeke、Hendrik F. T. Klare、Martin Oestreich
DOI:10.1002/chem.201402866
日期:2014.7.21
α‐proton rather than α‐deprotonation of the enolizable imine followed by reaction with an electrophilic silicon reagent. The silicon electrophile, stabilized by a sulfur atom, is generated by cooperative activation of an SiH bond at the RuS bond of a tethered ruthenium(II) thiolate complex. After transfer of the silicon cation onto the imine nitrogen atom, the remaining ruthenium(II) hydride fulfills
Addition of Alkynes to a Gallium Bis-Amido Complex: Imitation of Transition-Metal-Based Catalytic Systems
作者:Igor L. Fedushkin、Alexander S. Nikipelov、Alexander G. Morozov、Alexandra A. Skatova、Anton V. Cherkasov、Gleb A. Abakumov
DOI:10.1002/chem.201102243
日期:2012.1.2
Acetylene, phenylacetylene, and alkylbutynoates add reversibly to (dpp‐bian)Ga–Ga(dpp‐bian) (dpp‐bian=1,2‐bis[(2,6‐diisopropylphenyl)‐imino]acenaphthene) to give addition products [dpp‐bian(R1CCR2)]Ga–Ga[(R2CCR1)dpp‐bian]. The alkyne adds across the GaNC section, which results in new carbon–carbon and carbon–gallium bonds. The adducts were characterized by electron absorption, IR, and 1H NMR spectroscopy
One-Pot Synthesis of Au@SiO<sub>2</sub> Catalysts: A Click Chemistry Approach
作者:Vera A. Solovyeva、Khanh B. Vu、Zulkifli Merican、Rachid Sougrat、Valentin O. Rodionov
DOI:10.1021/co5000932
日期:2014.10.13
Using the copper-catalyzed azidealkyne cycloaddition click reaction, a library of triazole amphiphiles with a variety of functional polar heads and hydrophobic or superhydrophobic tails was synthesized. The amphiphiles were evaluated for their ability to stabilize small Au nanoparticles, and, at the same time, serve as templates for nanocasting porous SiO2. One of the Au@SiO2 materials thus prepared was found to be a highly active catalyst for the Au nanoparticle-catalyzed regioselective hydroamination of alkynes.
A Continuously Regenerable Chiral Ammonia Borane for Asymmetric Transfer Hydrogenations
作者:Qiwen Zhou、Wei Meng、Jing Yang、Haifeng Du
DOI:10.1002/anie.201806877
日期:2018.9.10
A novel chiral ammonia borane was designed and developed through the dehydrogenation of ammonia borane with a chiral phosphoric acid, which was highly effective for the asymmetric transfer hydrogenation of imines and β‐enamino esters to afford high levels of reactivities and enantioselectivities. Significantly, this chiral ammonia borane can be continuously regenerated during the transfer hydrogenation