Results 31 to 40 of about 971 (170)

Bis-bromine-1,4-diazabicyclo[2.2.2]octane Complex (DABCO-Br2): An Efficient and Versatile Reagent for Preparation of Dihydropyrimidinones as a New Protocol for the Biginelli Reaction [PDF]

شیمی کاربردی روز, 2011
A simple and efficient method for the one-pot Biginelli condensation reaction of aldehydes, β-dicarbonyl compounds and urea or thiourea employing tetrameric DABCO-bromine as a novel catalyst is described.
Gholam Hossein Mahdavinia, Mohammad Ali Bigdeli, Samaneh Karimi, Fatemeh Koti   +3 more
doaj   +1 more source

One pot three components solvent free synthesis of 4-substituted phenyl-2-(sulfanyl/oxo) pyrimidine-5-carboxylate derivatives

Results in Chemistry, 2022
An efficient and simple procedure for synthesis of 3,4-dihydropyrimidinone or 3,4-thioxopyrimidinone maintaining eco-friendly protocol by introducing acetic acid as an organo-catalyst in presence of molecular sieves as water absorbent is disclosed.
Sourav Handique, Priyanka Sharma
doaj   +1 more source

Ethyl 6-Methyl-2-oxo-4-{4-[(1-phenyl-1H-1,2,3-triazol-4-yl)methoxy]phenyl}-1,2,3,4-tetrahydropyrimidine-5-carboxylate

Molbank, 2019
The Biginelli reaction is an acid-catalyzed, three-component reaction between an aldehyde, a hydrogen methylene active compound, and urea (or its analogue) and constitutes a rapid and easy synthesis of highly functionalized heterocycles.
Itamar Luís Gonçalves, Gabriel Oliveira de Azambuja, Leonardo Davi, Guilherme Arraché Gonçalves, Luciano Porto Kagami, Gustavo Machado das Neves, João Pedro Silveira, Rômulo Faria Santos Canto, Vera Lucia Eifler-Lima   +8 more
doaj   +1 more source

Synthesis of structurally diverse 3,4-dihydropyrimidin-2(1H)-ones via sequential Biginelli and Passerini reactions

Beilstein Journal of Organic Chemistry, 2017
The Biginelli reaction was combined with the Passerini reaction for the first time in a sequential multicomponent tandem reaction approach. After evaluation of all possible linker components and a suitable solvent system, highly functionalized ...
Andreas C. Boukis, Baptiste Monney, Michael A. R. Meier   +2 more
doaj   +1 more source

Biginelli reaction

, 2007
Department of Chemistry, Punjabi University, Patiala-147 002, Punjab, India E-mail: j_sandhu2002@yahoo.com Manuscript received 28 May 2007, revised 17 July 2007, accepted 18 July 2007 Recent advances In Biginelli reaction are summarized including its latest mechanism, developments In building blocks, catalysts variations, optimization/acceleration of ...
Saini, Anil, Kumar, Sanjay, Sandhu, Jagir S.   +2 more
openaire   +2 more sources

Design and Synthesis of a Conformationally Rigid Mimic of the Dihydropyrimidine Calcium Channel Modulator SQ 32,926

Molecules, 2000
A conformationally rigid polyheterocycle (3) which mimics the putative receptorbound conformation of dihydropyridine-type calcium channel modulators is prepared in a seven-step reaction sequence based on a Biginelli-type cyclocondensation reaction.
Birgit Jauk, Tetiana Pernat, C. Oliver Kappe   +2 more
doaj   +1 more source

Síntese do monastrol e novos compostos de Biginelli promovida por In(OTf)3 Synthesis of monastrol and of new Biginelli compounds promoted by In(OTf)3

Química Nova, 2005
In this paper, we describe a practical route for the synthesis of Biginelli compounds using In(OTf)3. To study the generality of this catalyst, several examples using aromatic aldehydes, 1,3-dicarbonyl compounds, urea, and thiourea were investigated. The
Marla N. Godoi, Hellen S. Costenaro, Eliane Kramer, Paola S. Machado, Marcelo G. Montes D'Oca, Dennis Russowsky   +5 more
doaj   +1 more source

Microwave-Assisted Biginelli Reaction: An Old Reaction, a New Perspective [PDF]

Current Organic Synthesis, 2016
In this review, we tried to highlight the recent advances in the Biginelli reaction, leading to the synthesis of 3,4-dihydropyrimidin-2(1H)-ones, albeit only those conducted under microwave irradiation. The merits and drawbacks of these reactions are compared and discussed with those performed under conventional heating.
Mommahed Heravi, Majid, Ghavidel, Mahdieh, Heidari, Bahareh   +2 more
openaire   +1 more source

From Berzelius to Hyperspace: Previously Unrecognized Network of Reactivity in Textbook Brominations

Angewandte Chemie International Edition, EarlyView.
Robotic scans across multidimensional condition spaces of classic bromination reactions uncover regions of previously unrecognized reactivity, yielding new major products and novel substitution patterns. Correlation and anticorrelation analyses of product distributions across these hyperspaces enable reconstruction of the underlying mechanistic ...
Yankai Jia, Wai‐Shing Wong, Yasemin Bilgi‐Gadina, Louis P. J.‐L. Gadina, King‐Lam Kwong, Yanqiu Jiang, Nikolaos Vagkidis, Benito Marazzi, Peter R. Schreiner, Bartosz A. Grzybowski   +9 more
wiley   +1 more source

Ullmann‐Type N‐Heteroarylation of Nitrogen Heterocycles Catalyzed by Heterogeneous CuNPs/HKUST‐1

EcoEnergy, EarlyView.
A practical strategy for the direct synthesis of CuNPs/HKUST‐1 heterogeneous catalyst was developed and used for the catalyzing Ullmann‐type N‐arylation of N‐heterocycles with high yields, excellent recyclability, and low copper leaching. ABSTRACT Ullmann‐type C–N coupling is an essential reaction to construct functional nitrogen heterocycles, whereas ...
Shuai Yang, Fangshu Han, Yamin Dong, Liangting Wu, Wenchao Tang, Changyan Guo, Jide Wang, Ablimit Abdukader, Chenjiang Liu, Yonghong Zhang   +9 more
wiley   +1 more source