Results 11 to 20 of about 22,717 (244)

Modeling Pyran Formation in the Molybdenum Cofactor: Protonation of Quinoxalyl–Dithiolene Promoting Pyran Cyclization [PDF]

Inorganic Chemistry, 2019
Mononuclear Mo and W enzymes require a unique ligand known as molybdopterin (MPT). This ligand binds the metal through a dithiolene chelate, and the dithiolene bridges a reduced pyranopterin group. Pyran scission and formation have been proposed as a reaction of the MPT ligand that may occur within the enzymes to adjust reactivity at the Mo atom.
Douglas R. Gisewhite, Alexandra L. Nagelski, Daniel C. Cummins, Glenn P. A. Yap, Sharon J. N. Burgmayer   +4 more
core   +5 more sources

Synthesis of pyran and related natural products [PDF]

, 2012
This study was aimed at preparing dihydropyrans (DHPs) for the synthesis of 2,6-disubstituted tetrahydropyrans (THPs) in a diastereoselective manner. In an attempt to develop a novel methodology for the synthesis of DHPs from δ-hydroxy-β-ketoester and ...
Yeung, Bun
core   +6 more sources

pKa engineering of a near-infrared fluorescent probe for sensitive imaging of oxidative stress in atherosclerotic plaques. [PDF]

Smart Mol
A pKa‐engineered near‐infrared fluorescent probe (DCM‐2F‐B) enables sensitive imaging of oxidative stress in atherosclerotic plaques. Difluoro substitution lowers the phenolic hydroxyl pKa from 9.1 to 6.0, achieving near‐complete ionization at physiological pH.
Yu Q, Liang J, Zhou T, Chen Q, Yan X, Zheng Z, Wang H, Liu J, Dong Y, Zhu WH, Wang Q.   +10 more
europepmc   +2 more sources

A synthesis of carbasugar-sugar pseudodisaccharides via a cycloaddition-cycloreversion reaction of 2 H-Pyran-2-ones

, 2023
Cycloaddition of 3-carbomethoxy-2H-pyran-2-one to a vinylated sugar followed by the loss of bridging CO2 from the cycloadduct affords a cyclohexadiene which can be manipulated to a carbasugar-sugar pseudodisaccharide. © 2010 American Chemical Society.
Mohamed Haji Abdullahi (2246809), Kamyar Afarinkia (473836), Ian Scowen (17166964)   +2 more
core   +5 more sources

Diastereoselective Construction of Tetrahydro-Dispiro[indolinone-3,2′-pyran-5′,4″-pyrazolone] Scaffolds via an Oxa-Michael Cascade [4 + 2] Annulation Reaction

, 2022
A straightforward metal-free oxa-Michael cascade [4 + 2] annulation reaction was established between isatin-derived Morita–Baylis–Hillman (Is-MBH) alcohols with alkylidene pyrazolones to access structural diverse tetrahydro-dispiro[indolinone-3,2′-pyran ...
Venkitasamy Kesavan (1643218), Nandarapu Kumarswamyreddy (1643215), Kanduru Lokesh (13809438)   +2 more
core   +1 more source

Phenolic Compounds in Bacterial Inactivation: A Perspective from Brazil

Antibiotics, 2023
Phenolic compounds are natural substances that are produced through the secondary metabolism of plants, fungi, and bacteria, in addition to being produced by chemical synthesis.
Angélica Correa Kauffmann, Vinicius Silva Castro   +1 more
doaj   +1 more source

Scheme 1, Synthesis of fluorinated chalcones (1–20) and their 2-amino-pyridine-3-carbonitrile (21–40) and 2-amino-4H-pyran-3-carbonitrile (41–60) derivatives.

, 2022
Scheme 1, Synthesis of fluorinated chalcones (1–20) and their 2-amino-pyridine-3-carbonitrile (21–40) and 2-amino-4H-pyran-3-carbonitrile (41–60) derivatives.
M. Mukhlesur Rahman (2100193), Venu Sampath Golla (12884210), Bontha Venkata Subrahmanya Lokesh (12884213), Afzal Basha Shaik (12884216), Srinath Nissankararao (12884204), Rajendra Prasad Yejella (8937146), Surendra Babu Lagu (12884201), Richie R. Bhandare (12884207)   +7 more
core   +1 more source

Uses of Anthranilic Acid for the Synthesis of Dihydroquinazolin Derivatives with Antitumor, Anti-proliferative and Pim-1kinase Activities

Acta Chimica Slovenica, 2018
The reaction of anthranilic acid with ethoxycarbonylisothiocyanate gave the ethyl 4-oxo-2-thioxo-1,2-dihydroquinazoline-3(4H)-carboxylate (4). The reaction of compound 4 with hydrazine hydrate and a-halocarbonyl derivatives was found to give either ...
Rafat M. Mohareb, Peter A. Halim
doaj   +1 more source

Crystal structure of 6-(4-chlorophenyl)-6a-nitro-6a,6b,8,9,10,12a-hexahydro-6H,7H-spiro[chromeno[3,4-a]indolizine-12,11′-indeno[1,2-b]quinoxaline]

Acta Crystallographica Section E: Crystallographic Communications, 2019
The title compound, C35H27ClN4O3, crystallized with two independent molecules (A and B) in the asymmetric unit. In both molecules, the pyran and pyridine rings adopt envelope and chair conformations, respectively.
S. Syed Abuthahir, M. NizamMohideen, V. Viswanathan, D. Velmurugan, J. Nagasivarao   +4 more
doaj   +1 more source

(5S,6R)-6-Bromo-6-methyl-5-phenyl-3,4,5,6-tetra­hydro-2H-cyclo­penta­[b]pyran-7-one [PDF]

, 2011
The title compound, C15H15BrO2, was synthesized by a Brønsted acid-catalysed domino electrocyclization-halogenation reaction. The five-membered ring is essentially planar (r.m.s.
Bolte, Michael, Michael Bolte, Winai Ieawsuwan, Ieawsuwan, Winai   +3 more
core   +1 more source