Results 21 to 30 of about 18,263,514 (224)

1, 3-Dipolar Cycloadditions. LXXVI. Cycloadditions of Diazomethane to Substituted Butadienes

Chemical and Pharmaceutical Bulletin, 1975
1-Substituted butadienes (R=CH2, CH3, O, C3H5, CO2CH3, CN) and 2-phenylbutadiene accept diazomethane at the 3, 4-bond yielding 3-vinylpyrazoline derivatives. Tautomerization of the 1-to 2-pyrazolines takes place either at room temperature (R=CO2CH3, CN), on heating (R=C6H5) or on acid catalysis (R=H, CH3, OCH3) ; the 2-pyrazolines are characterized as ...
HUISGEN, ROLF, OHTA, AKIHIRO, GEITTNER, JOCHEN   +2 more
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Synthesis of novel pyrazoles via [2+3]-dipolar cycloaddition using alkyne surrogates [PDF]

Tetrahedron Letters, 2010
The syntheses of an important class of hitherto unreported novel pyrazoles are described. The regioselective synthesis of 1,3,4,5-tetrasubstituted pyrazoles was achieved by the Huisgen cyclization of nitrile imines with a trisubstituted bromoalkene. The substituted bromoalkene functions as an alkyne synthon which was used to construct 5,5-disubstituted
Sureshbabu, Dadiboyena, Edward J, Valente, Ashton T, Hamme   +2 more
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CUCURBITURIL-INDUCED 1,3-DIPOLAR CYCLOADDITION.

, 1986
CUCURBITURIL-INDUCED 1,3-DIPOLAR ...
MITA. ADHYA (7978196)
core   +6 more sources

Dimerization of propargyl and homopropargyl 6-azido-6-deoxy-glycosides upon 1,3-dipolar cycloaddition

Beilstein Journal of Organic Chemistry, 2008
Copper-catalyzed, thermal or microwave promoted 1,3-dipolar cycloaddition (Click Reaction) of 2-propynyl and 3-butynyl 2,3,4-tri-O-acetyl-6-azido-6-deoxy-glycopyranosides in the D-gluco, D-galacto and D-manno series afford the corresponding dimeric ...
Nikolas Pietrzik, Daniel Schmollinger, Thomas Ziegler   +2 more
doaj   +1 more source

Side-chain Modifications of Highly Functionalized 3(2H)-Furanones

Molecules, 2012
A series of 3(2H)-furanones, based on side-chain modifications of a parent 3(2H)-furanone, was synthesized in good yield. The parent compound was prepared by hydrogenolysis, and subsequent acid hydrolysis, of isoxazole derivatives.
Gil Valdo José da Silva, Maurício Gomes Constantino, Viviani Nardini, Shirley Muniz Machado Rodrigues   +3 more
doaj   +1 more source

Diastereoselective Formal 1,3-Dipolar Cycloaddition of Trifluoroethyl Amine-Derived Ketimines Enables the Desymmetrization of Cyclopentenediones

Molecules, 2023
In this research, a metal-free diastereoselective formal 1,3-dipolar cycloaddition of N-2,2,2-trifluoroethylisatin ketimines and cyclopentene-1,3-diones which can efficiently lead to the desymmetrization of cyclopentene-1,3-diones is developed.
Lin-Qiang Li, Jian-Qiang Zhao, Yan-Ping Zhang, Yong You, Zhen-Hua Wang, Zhen-Zhen Ge, Ming-Qiang Zhou, Wei-Cheng Yuan   +7 more
doaj   +1 more source

Domino Multicomponent Approach for the Synthesis of Functionalized Spiro-Indeno[1,2-b]quinoxaline Heterocyclic Hybrids and Their Antimicrobial Activity, Synergistic Effect and Molecular Docking Simulation

Molecules, 2019
An expedient synthesis of hitherto unexplored novel hybrid heterocycles comprising dispiropyrrolidine, N-styrylpiperidone and indeno[1,2-b]quinoxaline units has been developed via domino multicomponent 1,3-dipolar cycloaddition strategy employing a new ...
Abdulrahman I. Almansour, Natarajan Arumugam, Raju Suresh Kumar, Dhaifallah M. Al-thamili, Govindasami Periyasami, Karuppiah Ponmurugan, Naif Abdullah Al-Dhabi, Karthikeyan Perumal, Dhanaraj Premnath   +8 more
doaj   +1 more source

1,3-Dipolar Cycloadditions of N-Benzyl Furfuryl Nitrones with Electron-rich Alkenes

Molecules, 2000
The 1,3-dipolar cycloaddition reaction of N-benzyl-C-(2-furyl)nitrones with electron-rich alkenes gives preferentially trans-substituted 3,5-disubstituted isoxazolidines (endo approach).
Tomas Tejero, Francisco L. Merchan, Sonia Anoro, Pedro Merino   +3 more
doaj   +1 more source

Highly Enantio‐ and Diastereoselective Synthesis of Tetrahydrofuran Frameworks via Chiral Lewis Acid‐Catalyzed Formal [3+2] Cycloaddition of Allylsilanes

Angewandte Chemie, EarlyView.
The first catalytic asymmetric formal [3+2] cycloaddition of allylsilanes delivers cis‐2,5‐disubstituted tetrahydrofuran‐3‐ones that serve as versatile intermediates for the synthesis of diverse bioactive scaffolds. ABSTRACT A formal [3+2] cycloaddition via cyclization/1,2‐hydride shift initiated by nucleophilic attack of allylsilanes has been ...
Hosung Lee, Dong Kyu Kim, Pingshan Xin, Jin Won Lee, Terim Seo, Do Hyun Ryu   +5 more
wiley   +2 more sources

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