Influence of the catalyst structure in the cycloaddition of isocyanates to oxiranes promoted by tetraarylstibonium cations

2018 ◽  
Vol 47 (34) ◽  
pp. 11843-11850 ◽  
Author(s):  
Mengxi Yang ◽  
Nilanjana Pati ◽  
Guillaume Bélanger-Chabot ◽  
Masato Hirai ◽  
François P. Gabbaï
Keyword(s):  
Catalytic Activity ◽  
Lewis Acid ◽  
Acid Catalysts ◽  
Lewis Acid Catalysts ◽  
Catalyst Structure ◽  
Group 15 ◽  
Deficient Group

In the context of our work on electron deficient group 15 cations as Lewis acid catalysts, we have synthesized the triflate salts of a series of tetraarylstibonium cations and evaluated their catalytic activity for the cycloaddition of isocyanates to oxiranes.

scholarly journals A new class of solid Lewis acid catalysts based on interlayer expansion of layered silicates of the RUB-36 type with heteroatoms

2014 ◽  
Vol 2 (25) ◽  
pp. 9709-9717 ◽  
Author(s):  
Trees De Baerdemaeker ◽  
Hermann Gies ◽  
Bilge Yilmaz ◽  
Ulrich Müller ◽  
Mathias Feyen ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Lewis Acid ◽  
Layered Silicates ◽  
Acid Catalysts ◽  
Lewis Acid Catalysts ◽  
New Class

Interlayer expansion of the layered zeolite precursor RUB-36 in presence of an Fe source simultaneously achieved the expansion and the introduction of catalytic activity.

scholarly journals Synthesis, characterization, and properties of a benzofuran-based cage-shaped borate: photo activation of Lewis acid catalysts

2016 ◽  
Vol 52 (16) ◽  
pp. 3348-3351 ◽  
Author(s):  
Akihito Konishi ◽  
Ryosuke Yasunaga ◽  
Kouji Chiba ◽  
Makoto Yasuda
Keyword(s):  
Catalytic Activity ◽  
Lewis Acid ◽  
Light Irradiation ◽  
Lewis Acidity ◽  
Acid Catalysts ◽  
Lewis Acid Catalysts ◽  
Black Light

A benzofuran-based cage-shaped borate showed a higher degree of Lewis acidity and exhibited photo-activated catalytic activity under black-light irradiation.

scholarly journals Pt/CeO2 with residual chloride as reusable soft Lewis acid catalysts: application to highly efficient isomerization of allylic esters

2021 ◽  
Author(s):  
Qi-An Huang ◽  
Asahi Haruta ◽  
Yuhya Kumamoto ◽  
Haruno Murayama ◽  
Eiji Yamamoto ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Lewis Acid ◽  
High Catalytic Activity ◽  
Acid Catalysts ◽  
Lewis Acid Catalysts ◽  
X Ray ◽  
Solvent Free Conditions ◽  
Highly Dispersed ◽  
Silica Alumina ◽  
Allylic Esters

Abstract Heterogeneous acid and base catalysts play a crucial role in many important chemical processes. Hard Lewis and Brønsted acid catalysts like silica-alumina and zeolites have been widely applied in numerous reactions; however, developing reusable and active soft Lewis acid catalysts remain a challenge. Herein, we demonstrate for the first time that a highly dispersed supported platinum catalyst can act as a heterogeneous soft Lewis acid. High turnover numbers and reusability were observed in the isomerization of allylic esters under solvent-free conditions. Moreover, the as-prepared catalysts are characterized by X-ray photoelectron spectroscopy (XPS) and X-ray absorption fine structure (XAFS) analyses, revealing that the highly dispersed Pt clusters with Pt–Cl bonds play a key role in the high activity. The residual chloride anion enhances the Lewis acidity of the Pt metal center and thus improves the catalytic activity. Simultaneously, the high catalytic activity of Pt/CeO2 with residual chloride and the soft Lewis acid mechanism are also proved by density functional theory (DFT) calculations based on the model reaction.

Efficient Synthesis of β-Aminoacrylates and β-Enaminones Catalyzed by Zn(OAc)2·2H2O

2005 ◽  
Vol 70 (11) ◽  
pp. 1943-1952 ◽  
Author(s):  
Ramandeep Kaur Vohra ◽  
Jean-Luc Renaud ◽  
Christian Bruneau
Keyword(s):  
Catalytic Activity ◽  
Lewis Acid ◽  
Primary Amines ◽  
Acid Catalysts ◽  
Efficient Synthesis ◽  
Substituted Anilines ◽  
Lewis Acid Catalysts ◽  
Mild Conditions ◽  
Good Catalytic Activity ◽  
Direct Condensation

The direct condensation of amines with β-ketoesters and β-diketones to produce functional enamine derivatives has been investigated with zinc Lewis acid catalysts. Zn(OAc)2·2H2O shows good catalytic activity and leads to a chemo- and stereoselective formation of (Z)-enamine derivatives from aliphatic primary amines and ring-substituted anilines under mild conditions.

Electrophilic phosphonium cations (EPCs) with perchlorinated-aryl substituents: towards air-stable phosphorus-based Lewis acid catalysts

2016 ◽  
Vol 45 (37) ◽  
pp. 14651-14657 ◽  
Author(s):  
Shawn Postle ◽  
Vitali Podgorny ◽  
Douglas W. Stephan
Keyword(s):  
Catalytic Activity ◽  
Lewis Acid ◽  
Acid Catalysts ◽  
Lewis Acid Catalysts ◽  
Phosphonium Cations

A series of fluorophosphonium cations incorporating (C6Cl5) substituents, [Ph2PF(C6Cl5)][B(C6F5)4] 8, [PhPF(C6Cl5)2][B(C6F5)4] 9, and [(C6F5)PF(C6Cl5)2][B(C6F5)4] 10, were prepared and tested for air stability and catalytic activity.

Hydrothermal synthesis of Sn-Beta zeolites in F−-free medium

2018 ◽  
Vol 5 (11) ◽  
pp. 2763-2771 ◽  
Author(s):  
Hao Xu ◽  
Xudong Wang ◽  
Peng Ji ◽  
Haihong Wu ◽  
Yejun Guan ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Lewis Acid ◽  
Crystal Size ◽  
Acid Catalysts ◽  
Free Medium ◽  
Lewis Acid Catalysts ◽  
Structure Directing Agent ◽  
Highly Active ◽  
Beta Zeolites

Sn-Beta zeolites, with high Sn content and smaller crystal size, hydrothermally synthesized in F−-free medium using N-cyclohexyl-N,N-dimethylcyclohexanaminium hydroxide as the structure-directing agent with the assistance of Na+ and seed, are highly active as Lewis acid catalysts.

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