Results 51 to 60 of about 11,559 (254)

Componentes voláteis do café torrado. Parte I: compostos heterocíclicos Volatile components in roasted coffee. Part I: heterocyclic compounds

Química Nova, 1999
A review of heterocyclic compounds in roasted coffee is presented. The contents, precursors and sensorial properties of furans, pyrroles, oxazoles, thiazoles, thiophenes, pyrazines and pyridines are discussed.
Carlos Alberto Bastos De Maria, Ricardo Felipe Alves Moreira, Luiz Carlos Trugo   +2 more
doaj   +1 more source

Recurrence of the oxazole motif in tubulin colchicine site inhibitors with anti-tumor activity

European Journal of Medicinal Chemistry Reports, 2021
Because of its wide spectrum of targets and biological activities, the oxazole ring is a valuable heterocyclic scaffold in the design of new therapeutic agents with anticancer, antiviral, antibacterial, anti-inflammatory, neuroprotective, antidiabetic ...
Marilia Barreca, Virginia Spanò, Maria Valeria Raimondi, Chiara Tarantelli, Filippo Spriano, Francesco Bertoni, Paola Barraja, Alessandra Montalbano   +7 more
doaj   +1 more source

Synthesis of Unsymmetric Bis(heteroaryl) Selenides by Rhodium‐Catalyzed Exchange Reaction of Heteroaryl Fluorides and Ethers Using Se‐Heteroaryl Carboselenoates

European Journal of Organic Chemistry, EarlyView.
Various unsymmetric bis(heteroaryl) selenides are synthesized by the rhodium‐catalyzed exchange reaction of heteroaryl fluorides and ethers with Se‐heteroaryl 1‐adamatanecarboselenoates. The synthetic method is applicable to a broad range of five‐ and six‐membered heteroaryl derivatives and provides compounds containing multiple heteroatoms.
Masana Yazaki, Wei Han, Ren Suzuki, Mieko Arisawa   +3 more
wiley   +1 more source

Intramolecular Pd(II)-Catalyzed Cyclization of Propargylamides: Straightforward Synthesis of 5-Oxazole-carbaldehydes [PDF]

, 2008
(Chemical Equation Presented) Direct synthesis of 2-substituted 5-oxazolecarbaldehydes was performed by intramolecular reaction of propargylamides through treatment with a catalytic amount of Pd(II) salts in the presence of a stoichiometric amount of ...
BECCALLI E. M, BORSINI E, BROGGINI G, G. PALMISANO, SOTTOCORNOLA S   +4 more
core   +1 more source

2,3‐Dichloro‐5,6‐Dicyano‐1,4‐Benzoquinone (DDQ)‐Mediated CC Bond Formation: Redox Strategies from Stoichiometric to Catalytic Systems

ChemistryOpen, EarlyView.
2,3‐Dichloro‐5,6‐dicyano‐1,4‐benzoquinone serves as a versatile oxidant and redox catalyst for CC bond formation through hydride abstraction or single‐electron transfer. Stoichiometric and catalytic systems enable benzylic, allylic, and aromatic CH activation under mild, metal‐free conditions, providing sustainable routes to complex and bioactive ...
Dohoon Cha, Sun‐Joon Min
wiley   +1 more source

Efficient and high-​yielding protocol for the synthesis of nitriles from aldehydes [PDF]

, 2010
An operationally simple and high-​yielding procedure was developed for the conversion of aryl aldehydes into the corresponding nitriles using p-​toluenesulfonic acid as a mild catalyst under microwave irradn.
Madhusudana Reddy, M.B., Pasha, M.A.
core   +1 more source

AlkaPlorer: A database‐driven explorer for natural alkaloids and derivatives

Journal of Integrative Plant Biology, EarlyView.
The alkaloid database AlkaPlorer integrates over 130,000 compounds across 12,250 species. By linking chemical structures with biological and evolutionary data, it reveals how these molecules evolve and function. This platform serves as a vital resource for AI‐driven discovery in plant metabolism and modern drug development. ABSTRACT Alkaloids, renowned
Jiahao Li, Tao Zeng, Hongquan Xu, Xu Kang, Minghui Liang, Ruibo Wu   +5 more
wiley   +1 more source

Azirinyl-Substituted Nitrile Oxides: Generation and Use in the Synthesis of Isoxazole Containing Heterocyclic Hybrids

Molecules
The procedure for the generation of azirinyl-substituted nitrile oxides by the reaction of 2-(diazoacetyl)-2H-azirines with tert-butyl nitrite while preserving the azirine ring has been developed.
Alexander S. Dudik, Timur O. Zanakhov, Ekaterina E. Galenko, Mikhail S. Novikov, Alexander F. Khlebnikov   +4 more
doaj   +1 more source

NMR‐Based Structural Analysis of Highly Substituted Pyridines From Kondrat'eva Aza‐Diels–Alder Cycloadditions

Magnetic Resonance in Chemistry, Volume 64, Issue 3, Page 324-332, March 2026.
We report the results from a kinetic and mechanistic investigation of an inverse‐electron‐demand Diels–Alder (IEDDA) cycloaddition involving an oxazole‐type diene synthesized via an Ugi–Zhu multicomponent reaction (UZ‐3CR). ABSTRACT Pyridines are a crucial class of heterocycles with widespread applications in natural products, pharmaceuticals, and ...
Galdina V. Suárez‐Moreno, Francisco Méndez, Atilano Gutierrez‐Carrillo, Mónica A. Rincón‐Guevara, Yoarhy A. Amador‐Sánchez, Alejandro Islas‐Jácome, Eduardo González‐Zamora   +6 more
wiley   +1 more source

Synthesis of new beta-amidodehydroaminobutyric acid derivatives and of new tyrosine derivatives using copper catalyzed C-N and C-O coupling reactions [PDF]

, 2012
Several beta-amidodehydroaminobutyric acid derivatives were prepared from N,C-diprotected beta-bromodehydroaminobutyric acids and amides by a copper catalyzed C-N coupling reaction.
Ferreira, Paula M. T., Pereira, Goreti, Vilaça, Helena   +2 more
core   +1 more source