نتایج جستجو برای: carbene reaction

تعداد نتایج: 419291  

2017
Juan M Sarria Toro Cristina García-Morales Mihai Raducan Ekaterina S Smirnova Antonio M Echavarren

Chloromethylgold(I) complexes of phosphine, phosphite, and N-heterocyclic carbene ligands are easily synthesized by reaction of trimethylsilyldiazomethane with the corresponding gold chloride precursors. Activation of these gold(I) carbenoids with a variety of chloride scavengers promotes reactivity typical of metallocarbenes in solution, namely homocoupling to ethylene, olefin cyclopropanation...

Journal: :Chemical science 2017
Xiang-Yu Chen Kun-Quan Chen De-Qun Sun Song Ye

The N-heterocyclic carbene-catalyzed oxidative [3 + 2] annulation of dioxindole and enals was developed, giving the corresponding spirocyclic oxindole-γ-lactones in good yields with high to excellent diastereo- and enantioselectivities. The challenging aliphatic enals worked effectively using this strategy. The oxidative cross coupling of homoenolate and enolate via single electron transfer was...

2016
Enrico Marelli Martin Corpet Yury Minenkov Rifahath M. Neyyappadath Alessandro Bismuto Giulia Buccolini Massimiliano Curcio Luigi Cavallo Steven P. Nolan

A palladium N-heterocyclic carbene catalyzed methodology for the synthesis of substituted, N-unprotected indoles and azaindoles is reported. The protocol permits access to various, highly substituted members of these classes of compounds. Although two possible reaction pathways (deprotonative and Heck-like) can be proposed, control experiments, supported by computational studies, point toward a...

Journal: :Chemical communications 2016
Ming Chen Ning Sun Haoyi Chen Yuanhong Liu

A gold-catalyzed regioselective [3+2] cycloaddition of ynamides with 1,4,2-dioxazoles was developed and offers a novel approach to obtain highly functionalized oxazoles under mild reaction conditions. 1,4,2-Dioxazole was found to act as an efficient N-acyl nitrene equivalent to trigger a facile generation of α-imino gold-carbene intermediate through the elimination of a ketone.

Journal: :Physical chemistry chemical physics : PCCP 2011
Weiwei Wang Jingshuang Dang Xiang Zhao

Density functional theory (DFT) methods have been applied to study C(32) fullerenes built from four-, five-, and six-membered rings. The relative energies of pure C(32) fullerenes have been evaluated to locate three most stable structures, 32:D(4d) with two squares, 1:D(3) without square and 5:C(s) with one square. Structural analysis reveals that there is a rearrangement pathway between the lo...

Journal: :Biomedicine and chemical sciences 2022

In this short review definition, mechanism, and recent developments of the Stetter reaction, in period last ten years from 2011 to 2021 are presented. This reaction comprises N-heterocyclic carbene (NHC)-catalyzed umpolung aldehydes followed by their capturing with activated carbon-carbon double bonds (Michael acceptors). work includes also progresses inter-molecular intra-molecular versions en...

Journal: :The Journal of chemical physics 2013
Kimberly N Urness Qi Guan Amir Golan John W Daily Mark R Nimlos John F Stanton Musahid Ahmed G Barney Ellison

A silicon carbide microtubular reactor has been used to measure branching ratios in the thermal decomposition of furan, C4H4O. The pyrolysis experiments are carried out by passing a dilute mixture of furan (approximately 0.01%) entrained in a stream of helium through the heated reactor. The SiC reactor (0.66 mm i.d., 2 mm o.d., 2.5 cm long) operates with continuous flow. Experiments were perfor...

Journal: :Angewandte Chemie 2012
Annemarie J C Walters Oliver Troeppner Ivana Ivanović-Burmazović Cristina Tejel M Pilar del Río Joost N H Reek Bas de Bruin

Polymers bearing polar functionalities are important materials, since they exhibit beneficial properties with respect to adhesion, paint/printability and surface properties. Commercial synthesis of these materials is mainly based on radical processes, which (so far) only allow poor control over the stereochemistry of the resulting polymers. 2 ] Stereo-controlled polymerisation generally require...

Journal: :Chemical communications 2014
Rüdiger Bertermann Holger Braunschweig Christopher K L Brown Alexander Damme Rian D Dewhurst Christian Hörl Thomas Kramer Ivo Krummenacher Bernd Pfaffinger Krzysztof Radacki

Ethynyldimesitylborane (1) is synthesised via salt elimination and its reactivity towards NHCs is studied. Depending on their size, NHCs attack either at the boron atom or at the β-alkynyl carbon atom. Steric control over the reaction was probed by reactions with N-heterocyclic carbenes yielding a carbene-borane adduct (2), a 1-boraindane (3), and the first structurally characterised borataalle...

Journal: :Chemical communications 2006
Anna Michrowska Łukasz Gułajski Karol Grela

The air stable asarone-derived Ru carbene 16, a robust olefin metathesis catalyst, can be easily separated after reaction by deposition on silica gel and reused up to nine times. This procedure provides products of excellent purity with low Ru content.

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