Results 31 to 40 of about 5,322 (210)

1,4- Addition of diazomethane to a heterodiene: a direct preparation of the oxazolic ring

Anais da Academia Brasileira de Ciências, 2007
The reaction of naphthoquinone-oximes (3) and (4) with diazomethane yields directly, in one step, the oxazoles (5) and (6), respectively.A reação das naphthoquinona-oximas (3) e (4) com diazometano fornece diretamente, em uma etapa, os oxazóis (5) e (6),
Flávio da S. Emery, Raphael S.F. Silva, Kelly C.G. de Moura, Maria C.F.R. Pinto, Mauro B. Amorim, Valéria R.S. Malta, Regina H.A. Santos, Kátia M. Honório, Albérico B.F. da Silva, Antonio V. Pinto   +9 more
doaj   +1 more source

2-(3-Bromophenyl)imidazo[2,1-b]oxazole

Molbank, 2023
The microwave-assisted reaction of 2-nitroimidazole with 3-bromophenacyl bromide in the presence of potassium carbonate as a base and dimethylformamide as a solvent afforded 2-(3-bromophenyl)imidazo[2,1-b]oxazole.
Ángel Cores, Mercedes Villacampa, J. Carlos Menéndez   +2 more
doaj   +1 more source

A de‐novo Approach Towards Divergent [3+2π/σ] Photocycloadditions of Nitrones via Assembly‐Controlled Kinetic Electron Transfer Gating

Angewandte Chemie, Volume 138, Issue 43, 19 October 2026.
A metal‐free photocatalytic platform converts nitrones into 4‐isoxazolines and oxa–aza–bicycloheptanes through divergent [3+2π/σ] cycloadditions. Assembly‐controlled kinetic electron transfer gating dictates substrate activation, enabling selective reactivity beyond thermodynamic expectations.
Nayan Saha, Rajesh Kancherla, Jorge Escorihuela, Shana Chandran, Mrinal K. Bera, Magnus Rueping, Burkhard König   +6 more
wiley   +2 more sources

Investigation on the reactivity of α-azidochalcones with carboxylic acids: Formation of α-amido-1,3-diketones and highly substituted 2-(trifluoromethyl)oxazoles

Beilstein Journal of Organic Chemistry, 2015
The reaction of α-azidochalcones with carboxylic acids has been investigated resulting in the formation of α-amido-1,3-diketones under microwave irradiation via in situ formation of 2H-azirine intermediates.
Kandasamy Rajaguru, Arumugam Mariappan, Rajendran Suresh, Periasamy Manivannan, Shanmugam Muthusubramanian   +4 more
doaj   +1 more source

The LANCA three-component reaction to highly substituted β-ketoenamides – versatile intermediates for the synthesis of functionalized pyridine, pyrimidine, oxazole and quinoxaline derivatives

Beilstein Journal of Organic Chemistry, 2019
The LANCA three-component reaction of lithiated alkoxyallenes LA, nitriles N and carboxylic acids CA leads to β-ketoenamides KE in good to excellent yields.
Tilman Lechel, Roopender Kumar, Mrinal K. Bera, Reinhold Zimmer, Hans-Ulrich Reissig   +4 more
doaj   +1 more source

Palladium-Catalyzed C–H Arylation of (Benzo)oxazoles or (Benzo)thiazoles with Aryltrimethylammonium Triflates

, 2015
The C–H arylation of (benzo)­oxazoles or (benzo)­thiazoles with aryltrimethylammonium triflates was carried out via Pd-catalyzed C–H/C–N cleavage.
Jian-Long Tao (1456900), Feng Zhu (685), Zhong-Xia Wang (665287)   +2 more
core   +1 more source

Recent Advances on O-Ethoxycarbonyl and O-Acyl Protected Cyanohydrins

Molecules, 2021
Ethoxycarbonyl cyanohydrins and O-acyl cyanohydrins are examples of O-protected cyanohydrins in which the protecting group presents an electrophilic center, contributing to additional reaction pathways.
Héctor Manuel Torres Domínguez, Luis Mauricio Hernández Villaverde, Ronan Le Lagadec   +2 more
doaj   +1 more source

Active Metal Template Synthesis of Rotaxanes From BINOL‐Phosphate Macrocycles

Angewandte Chemie International Edition, EarlyView.
The use of macrocyclic BINOL‐phosphates allows for the active metal template synthesis of [2]rotaxanes via Cu(I)‐mediated alkyne‐azide cycloaddition. DFT calculations, control experiments, and kinetic experiments support a dinuclear phosphate‐Cu2 intermediate.
Nikolai Brodt, Sophia Stadtfeld, Somayyeh Kheirjou, Tibor Schumski, Adrian M. Bialowons, Dennis Jansen, Felix Niemeyer, Torsten Schaller, Gebhard Haberhauer, Jan Riebe, Jochen Niemeyer   +10 more
wiley   +1 more source

Synthesis of 2,4,5-trisubstituted oxazoles [PDF]

, 2005
2,4,5-Trisubstituted oxazoles were synthesized in good yields starting from alpha-methylene ketones by nitrosation, condensation with aldehydes and reduction with zinc in acetic acid at 40 degrees C.
Zhang, GL, Chinese Acad Tradit Chinese Med, Chengdu Inst Biol, Chengdu 610041, Peoples R China., Cai, XH, Yang, HJ, Zhang, GL   +3 more
core  

A Modular Synthesis of C5‐Sulfenyl Thiazoles via an Intermolecular Pummerer Rearrangement: An Underexplored Scaffold for Medicinal Chemistry

Angewandte Chemie, Volume 138, Issue 41, 5 October 2026.
Modular access to underexplored C5‐sulfenyl thiazoles via an intermolecular Pummerer rearrangement is reported. The methodology exhibits a broad functional group tolerance enabling the seamless design of trisubstituted thiazole cores bearing a sulfur handle for further elaboration.
Joe L. Smy, Theo C. Webb, Barnaby W. Greenland, S. Mark Roe, John Spencer, Storm Hassell‐Hart   +5 more
wiley   +2 more sources