Results 181 to 190 of about 24,842 (217)

Thiourea-Quaternary Ammonium Salt Catalyzed Asymmetric 1, 3-Dipolar Cycloaddition of Imino Esters To Construct Spiro[pyrrolidin-3,3'-oxindoles].

Organic Letters, 2016
A highly enantioselective 1,3-dipolar cycloaddition of imino esters with methyleneindolinones has been realized by using readily available thiourea-quaternary ammonium salts as phase-transfer catalysts, enabling efficient construction of a range of ...
Jiaxing Zhang, Hongyu Wang, Qiao-wen Jin, Changwu Zheng, Gang Zhao, Yongjia Shang   +5 more
semanticscholar   +1 more source

The asymmetric synthesis of CF3-containing spiro[pyrrolidin-3,2'-oxindole] through the organocatalytic 1,3-dipolar cycloaddition reaction.

Chemical Communications, 2015
A new strategy for the construction of optically active 5'-CF3 spiro[pyrrolidin-3,2'-oxindole] was described. A series of unprecedented 1,3-dipoles were obtained by condensation of CF3CH2NH2 with isatins.
M. Ma, Yuan-Yuan Zhu, Quan Sun, Xiaoyuan Li, Jinhuan Su, Long Zhao, Yanyan Zhao, Shuai Qiu, Wenjin Yan, Kairong Wang, Rui Wang   +10 more
semanticscholar   +1 more source

1,3-Dipolar Cycloadditions in Aqueous Media

HETEROCYCLES, 2006
AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
openaire   +4 more sources

Alkenyl Arenes as Dipolarophiles in Catalytic Asymmetric 1,3-Dipolar Cycloaddition Reactions of Azomethine Ylides.

Angewandte Chemie, 2016
The use of alkenyl arenes as dipolarophiles in the catalytic asymmetric 1,3-dipolar cycloaddition of azomethine ylides is reported. Under appropriate reaction conditions with a CuI or AgI catalyst either the exo or the endo adduct was obtained with high ...
Ana Pascual-Escudero, A. de Cózar, F. Cossío, J. Adrio, J. Carretero   +4 more
semanticscholar   +1 more source

Synthesis of Pyrrole-Fused Corannulenes: 1,3-Dipolar Cycloaddition of Azomethine Ylides to Corannulene.

Angewandte Chemie, 2017
In the long history of corannulene chemistry, the 1,3-dipolar cycloaddition to corannulene is unprecedented. Reported herein is the 1,3-dipolar cycloaddition of a polycyclic aromatic azomethine ylide to corannulene, a reaction which occurs exclusively at
Yuki Tokimaru, S. Ito, K. Nozaki
semanticscholar   +1 more source

Polyacrylonitrile Fiber Supported N-Heterocyclic Carbene Ag(I) As Efficient Catalysts for Three-Component Coupling and Intramolecular 1,3-Dipolar Cycloaddition Reactions under Flow Conditions

, 2017
A series of recoverable and reusable N-heterocyclic carbene silver complexes supported on polyacrylonitrile fiber were prepared and characterized. Their catalytic performances in three-component coupling reactions of aldehydes, amines, and alkynes (A3 ...
Jian Cao, Gang Xu, Pengyu Li, M. Tao, Wenqin Zhang   +4 more
semanticscholar   +1 more source

Catalytic Asymmetric 1,3-Dipolar Cycloaddition of β-Fluoroalkylated α,β-Unsaturated 2-Pyridylsulfones with Nitrones for Chiral Fluoroalkylated Isoxazolidines and γ-Amino Alcohols.

Angewandte Chemie, 2017
2-Pyridylsulfone- and fluoroalkylated group-activated olefins underwent highly efficient diastereo- and enantioselective 1,3-dipolar cycloadditions across various aromatic and aliphatic nitrones in the presence of a chiral NiII /bis(oxazoline) catalyst ...
Xing Yang, Feng Cheng, Ying‐Da Kou, Shuai Pang, Yong-Cun Shen, Yiyong Huang, N. Shibata   +6 more
semanticscholar   +1 more source

ChemInform Abstract: Enantioselective Copper‐Catalyzed 1,3‐Dipolar Cycloadditions

ChemInform, 2008
AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Levi M. Stanley, Mukund P. Sibi
openaire   +4 more sources

What Controls the Reactivity of 1,3‐Dipolar Cycloadditions?

Angewandte Chemie International Edition, 2009
AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Bernd Engels, Manfred Christl
openaire   +4 more sources

p-Toluenesulfonic acid mediated 1,3-dipolar cycloaddition of nitroolefins with NaN3 for synthesis of 4-aryl-NH-1,2,3-triazoles.

Organic Letters, 2014
A p-TsOH-mediated 1,3-dipolar cycloaddition of nitroolefins and sodium azide for the synthesis of 4-aryl-NH-1,2,3-triazoles has been developed. p-TsOH was discovered as a vital additive in this type of 1,3-dipolar cycloaddition.
Xu Quan, Zhihui Ren, Yaoyu Wang, Zheng‐Hui Guan   +3 more
semanticscholar   +1 more source