Results 131 to 140 of about 41,109 (281)

New Quinazolin-4(3H)-One Derivatives Incorporating Isoxazole Moiety as Antioxidant Agents: Synthesis, Structural Characterization, and Theoretical DFT Mechanistic Study

Pharmaceuticals
Background: This research centers on the development and spectroscopic characterization of new quinazolin-4(3H)-one-isoxazole derivatives (5a–e). The aim was to investigate the regioselectivity of the 1,3-dipolar cycloaddition involving arylnitriloxides ...
Yassine Rhazi, Riham Sghyar, Noemi Deak, Bouchra Es-Sounni, Bouchra Rossafi, Albert Soran, Mustapha Laghmari, Azize Arzine, Asmae Nakkabi, Khalil Hammani, Samir Chtita, Mohammed M. Alanazi, Gabriela Nemes, Mohamed El. Yazidi   +13 more
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

1,3-Dipolar cycloaddition reactivities of perfluorinated aryl azides with enamines and strained dipolarophiles.

Journal of the American Chemical Society, 2015
The reactivities of enamines and predistorted (strained) dipolarophiles toward perfluoroaryl azides (PFAAs) were explored experimentally and computationally. Kinetic analyses indicate that PFAAs undergo (3 + 2) cycloadditions with enamines up to 4 orders
Sheng Xie, Steven A. Lopez, O. Ramström, Mingdi Yan, K. Houk   +4 more
semanticscholar   +1 more source

Advances in Mechanochemical Methods for One‐Pot Multistep Organic Synthesis

Chemistry – A European Journal, Accepted Article.
Mechanochemical synthesis has emerged as a powerful and more sustainable alternative to conventional solution‐based methods, offering advantages such as no or only minimal solvent use, reduced reaction times, and simplified operational conditions.
Michael Schnürch, Nina Biedermann
wiley   +1 more source

β‐Lactam Ylidenes: An Overlooked Class of N‐Heterocyclic Carbenes

Chemistry – A European Journal, EarlyView.
A highly modular synthetic approach toward four‐membered β‐lactam carbenes (BLCs) is presented. BLCs feature moderate σ‐donor and strong π‐acceptor character, leading to a pronounced ambiphilic reactivity which includes the formation of olefinic dimers as well as unprecedented N2‐bridged dimers, oxirane formation with acetone, and fragmentation to ...
Leonard Karl, Daniel Deißenbeck, Jan Meisner, Christian Ganter   +3 more
wiley   +1 more source

Bulky Ligands for Open Channels: Manganese (II) sql MOFs from Pyridyl‐Functionalised [3]Polynorbornanes

ChemPlusChem, EarlyView.
Two new [n]polynorbornane based ligands (LMe and LEt) form isoreticular sql MOFs with crystal structure analysis revealing neatly aligned nets creating large accessible 1D channels with a distinct lack of interpenetration. The ester moieties of these ligands orient into the channels highlighting potential of these ligands for the construction of MOFs ...
William Murrell, Pavel M. Usov, Carol Hua, Fred Pfeffer   +3 more
wiley   +1 more source

A Diastereoselective Synthesis of Dispiro[oxindole-cyclohexanone]pyrrolidines by 1,3-Dipolar Cycloaddition

Molecules, 2017
For the first time, arylmethylidene cyclohexanones that are non-symmetrical due to the presence of peripheral substituents were studied in 1,3-dipolar cycloaddition reactions.
Alexander Anis’kov, Irina Klochkova, Roman Tumskiy, Alevtina Yegorova   +3 more
doaj   +1 more source

Catalytic Asymmetric Inverse-Electron-Demand 1,3-Dipolar Cycloaddition of C,N-Cyclic Azomethine Imines with Azlactones: Access to Chiral Tricyclic Tetrahydroisoquinolines.

Angewandte Chemie, 2016
Reported herein is a bifunctional-organocatalyst-mediated enantioselective inverse-electron-demand 1,3-dipolar cycloaddition of C,N-cyclic azomethine imines with azlactones.
Xihong Liu, Yijie Wang, Dongxu Yang, Jinlong Zhang, Dongsheng Liu, W. Su   +5 more
semanticscholar   +1 more source

Efficient synthesis of 1,3-diaryl-4-halo-1H-pyrazoles from 3-arylsydnones and 2-aryl-1,1-dihalo-1-alkenes

Beilstein Journal of Organic Chemistry, 2011
An efficient synthesis of 1,3-diaryl-4-halo-1H-pyrazoles was achieved. The synthesis involves the [3 + 2] dipolar cycloaddition of 3-arylsydnones and 2-aryl-1,1-dihalo-1-alkenes. The process proceeds smoothly in moderate to excellent yields. 1,3-Diaryl-4-
Yiwen Yang, Chunxiang Kuang, Hui Jin, Qing Yang, Zhongkui Zhang   +4 more
doaj   +1 more source

New cofactor supports α,β-unsaturated acid decarboxylation via 1,3-dipolar cycloaddition

Nature, 2015
The bacterial ubiD and ubiX or the homologous fungal fdc1 and pad1 genes have been implicated in the non-oxidative reversible decarboxylation of aromatic substrates, and play a pivotal role in bacterial ubiquinone (also known as coenzyme Q) biosynthesis ...
K. Payne, M. White, K. Fisher, B. Khara, S. Bailey, David Parker, N. Rattray, D. Trivedi, R. Goodacre, R. Beveridge, P. Barran, S. Rigby, N. Scrutton, Sam Hay, D. Leys   +14 more
semanticscholar   +1 more source