Results 11 to 20 of about 1,523 (159)

Enantioselective Cycloaddition Reactions Catalyzed by BINOL-Derived Phosphoric Acids and N-Triflyl Phosphoramides: Recent Advances

Molecules, 2015
Over the last several years there has been a huge increase in the development and applications of new efficient organocatalysts for enantioselective pericyclic reactions, which represent one of the most powerful types of organic transformations.
Felix E. Held, Dominik Grau, Svetlana B. Tsogoeva   +2 more
doaj   +1 more source

Additive-assisted regioselective 1,3-dipolar cycloaddition of azomethine ylides with benzylideneacetone

Beilstein Journal of Organic Chemistry, 2014
1,3-Dipolar cycloadditions of isatins, benzylamine and benzylideneacetones were studied to prepare a series of novel spiropyrrolidine-oxindoles – 4′-acetyl-3′,5′-diarylspiro[indoline-3,2′-pyrrolidin]-2-ones and 3′-acetyl-4′,5′-diarylspiro[indoline-3,2 ...
Chuqin Peng, Jiwei Ren, Jun-An Xiao, Honggang Zhang, Hua Yang, Yiming Luo   +5 more
doaj   +1 more source

Synthesis and 1,3-Dipolar Cycloaddition Reactions of Chiral Maleimides

Molecules, 1997
New routes to the synthesis of various novel chiral maleimides are described. The oxabicyclic anhydride 2 readily available exo-Diels-Alder adduct of furan and maleic anhydride was used as a vehicle, which in turn reacted with hydrochlorides of amino ...
Lubor Fisera, Vladimir Ondrus
doaj   +1 more source

Synthesis and cytotoxic evaluation of substituted 3-(3′-indolyl-/3′-pyridyl)-isoxazolidines and bis-indoles

Acta Pharmaceutica Sinica B, 2012
Regio- and stereoselective 1,3-dipolar cycloadditions of C-(3-indolyl)-N-phenylnitrone (10) were carried out with different mono-substituted, disubstituted and cyclic dipolarophiles under mono-mode microwave irradiation to obtain substituted 3-(indol-3 ...
Vishal Sharma, Raman Kalia, Tilak Raj, Vivek K. Gupta, Nitasha Suri, Ajit K. Saxena, Deepak Sharma, Surinderjit S. Bhella, Gurpinder Singh, Mohan Paul S. Ishar   +9 more
doaj   +1 more source

Synthesis of Spiroisoxazolines by 1,3-Dipolar Cycloaddition

Molecules, 1997
The cycloaddition of the chiral nitrile oxide 1 to 1-R-substituted 3,3-methylene-5,5-dimethyl-2-pyrrolidinones 2 (where R is H, n-butyl-, 1,1-dimethylethoxycarbonyl-, 1-methylethenyl- and acetyl-) proceeds regioselectively under the formation of ...
Peter Ertl, Vladimír Ondrus, Lubor Fisera, Peter Micuch   +3 more
doaj   +1 more source

Photo-induced 1, 3-Dipolar Cycloaddition Reaction of Aziridinedicarboximide

Chemical and Pharmaceutical Bulletin, 1969
Cycloaddition reaction of N-(p-methoxyphenyl)-1-benzyl-2, 3-aziridinedicarboximide (8) with dimethyl acetylenedicarboxylate (3) was not effected thermally, but under irradiation it resulted in a formation of 1 : 1-cycloadducts, I (9), II (17), and III (34), and a 1 : 2-cycloadduct IV (38).
OIDA, SADAO, OHKI, EIJI
openaire   +2 more sources

Theoretical Study of 1,3-Dipolar Cycloadditions Regioselectivity of Benzyl Azide with Glycosyl-O Acetylene Using Density Functional Theory (DFT)

Orbital: The Electronic Journal of Chemistry, 2017
A theoretical study of 1,3-cycloaddition has been carried out using density functional theory (DFT) methods at the B3LYP/6-31G* level. The regioselectivity of the reaction have been clarified through different theoretical approaches: Case of a Two-Center
Adib Ghaleb, Adnane Aouidate, Abdelouahid Sbai, Tahar Lakhlifi, Hamid Maghat, Mouhamed Bouachrine   +5 more
doaj   +1 more source

Synthesis of 2-substituted 9-oxa-guanines {5-aminooxazolo[5,4-d]pyrimidin-7(6H)-ones} and 9-oxa-2-thio-xanthines {5-mercaptooxazolo[5,4-d]pyrimidin-7(6H)-ones}

Beilstein Journal of Organic Chemistry, 2008
Oxazolo[5,4-d]pyrimidines can be considered as 9-oxa-purine analogs of naturally occurring nucleic acid bases. Interest in this ring system has increased due to recent reports of biologically active derivatives.
Subrata Mandal, Wen Tai Li, Yan Bai, Jon D. Robertus, Sean M. Kerwin   +4 more
doaj   +1 more source

Applications of Azide-Based Bioorthogonal Click Chemistry in Glycobiology

Molecules, 2013
Click chemistry is a powerful chemical reaction with excellent bioorthogonality features: biocompatible, rapid and highly specific in biological environments.
Xiu Zhang, Yan Zhang
doaj   +1 more source

One-pot Microwave-Assisted Synthesis of 1H-Phenanthro[9,10- d][1,2,3]triazole

Molbank, 2008
In this study, a fast and good yield one-pot microwave-assisted synthesis (45 seconds) of 1H-phenanthro[9,10-d][1,2,3]triazole by a 1,3-dipolar cycloaddition reaction of sodium azide and 9-bromophenanthrene in the presence of potassium tert-butoxide in ...
Mehrak Faraji, Avat Arman Taherpour
doaj   +1 more source