Results 31 to 40 of about 20,507 (274)

Selective Mono Bromination of 1,4-Dihydropyridines [PDF]

Iranian Journal of Chemistry & Chemical Engineering, 1997
2-monobromomethyl 1,4-dihydropyridines is selectively synthesized by bromination of the parent compound by 1.1 equivalents of pyridinium bromide perbromide in dichloromethane/pyridine at -20 °C. The same reagent in dichloromethane at 0 °C produce the 2,6-
Yousef Rastgar Mirzaei, Adeleh Moshtaghi Zenouz   +1 more
doaj  

A convenient domino access to substituted alkyl 1,2-dihydropyridine- 3carboxylates from propargyl enol ethers and primary amines [PDF]

, 2016
A convenient domino access to substituted alkyl 1,2-dihydropyridine-3- carboxylates from propargyl enol ethers and primary amines was reported. A solution of propargyl sinyl ether 1a and p-anisidine in toluene was placed in a microwave-special closed ...
García-Tellado, Fernando, Méndez-Abt, Gabriela, Tejedor, David   +2 more
core   +1 more source

A copper-benzotriazole based coordination polymer catalyzes the efficient one-pot synthesis of (N'-substituted)-hydrazo-4-aryl-1,4-dihydropyridines from azines [PDF]

, 2017
A series of new (N’-substituted)-hydrazo-4-aryl-1,4 dihydropyridines were successfully synthesized via a facile one pot catalytic pathway utilizing azines and propiolate esters as starting materials and 1D Cu benzotriazoles based coordination polymer as ...
Batten, Battula, Coles, Cukurovali, Deng, Efe, El-Alali, Eriksen, Fountoulaki, Fountoulaki, Gati, Girling, Gryparis, Hantzsch, Himo, Hu, Ioan, Jiang, Jiang, Jones, Kappe, Karmakar, Kostakis, Leong, Mendes, Narayanaswamy, Patra, Quinonero, Rádl, Safak, Safari, Stout, Sueki, Sueki, Verma, Verma, Verner, Wan, Zhao, Zhou   +39 more
core   +1 more source

Eco-Friendly Methodology to Prepare N-Heterocycles Related to Dihydropyridines: Microwave-Assisted Synthesis of Alkyl 4-Arylsubstituted-6-chloro-5-formyl-2-methyl-1,4-dihydropyridine-3-carboxylate and 4-Arylsubstituted-4,7-dihydrofuro[3,4-b]pyridine-2,5(1H,3H)-dione

Molecules, 2011
Here we describe the efficient synthesis of alkyl 4-arylsubstituted-6-chloro-5-formyl-2-methyl-1,4-dihydropyridine-3-carboxylates and 4-arylsubstituted-4,7-dihydro-furo[3,4-b]pyridine-2,5(1H,3H)-diones via microwave-accelerated reaction of alkyl 4 ...
Fernando Albericio, Nazario Martín, Hortensia Rodríguez, Osnieski Martin, Margarita Suarez   +4 more
doaj   +1 more source

Ultrasound Mediated, Green Innovation for the Synthesis of Polysubstituted 1,4-Dihydropyridines [PDF]

, 2016
An elegant, atom efficient protocol via a one-pot four-component cyclocondensation reaction of aromatic aldehydes, malononitrile, acetylenedicarboxylates and arylamines catalyzed by copper(i) iodide in aqueous medium under ultrasound irradiation has been
Pasha, M.A., Riyaz-ur-Rahaman Khana, ., Santhosh Govindaraju, ., Sumaiya Tabassum, .   +3 more
core   +1 more source

Developing lithium chemistry of 1,2-dihydropyridines : from kinetic intermediates to isolable characterized compounds [PDF]

, 2015
Generally considered kinetic intermediates in addition reactions of alkyllithiums to pyridine, 1-lithio-2-alkyl-1,2-dihydropyridines have been rarely isolated or characterized. This study develops their "isolated" chemistry.
Armstrong, David R., Harris, Catriona M. M., Kennedy, Alan R., Liggat, John J., McLellan, Ross, Mulvey, Robert E., Robertson, Stuart D., Urquhart, Matthew D. T.   +7 more
core   +1 more source

Beyond right or wrong: How partial credit scoring on multiple‐choice questions improves student performance and assessment perceptions

British Journal of Clinical Pharmacology, EarlyView.
Aims In this study, we examined the effects of assigning partial credit to selected answer choices on student performance and perceptions in a pharmacology course using Type A multiple‐choice questions (MCQs). Methods Partial credit scoring was incorporated into quizzes and exams in a 10‐week pharmacology course for postbaccalaureate premedical ...
Stephen D. Schneid, Chris Armour, Katharina Brandl   +2 more
wiley   +1 more source

Comparison between 1,2-Dihydropyridine and 1,4-Dihydropyridine on Hydride-Donating Ability and Activity

Molecules, 2022
In this paper, detailed comparisons of the driving force in thermodynamics and intrinsic force in the kinetics of 1,2-dihydropyridine and 1,4-dihydropyridine isomers of PNAH, HEH, and PYH in hydride transfer reactions are made. For 1,2-PNAH and 1,4-PNAH, the values of the thermodynamic driving forces, kinetic intrinsic barriers, and thermo-kinetic ...
Jin-Ye Zhang, Xiao-Qing Zhu
openaire   +3 more sources

Organophotoredox/Cobalt‐Catalyzed Retro‐Hydroformylation of Aldehydes

ChemistryEurope, EarlyView.
A new photoredox/cobalt retro‐hydroformylation is developed. This one‐pot two‐step process involves the in situ formation of the corresponding 1,4‐dihydropyridine as key intermediate. Under mild reaction conditions, alkenes are efficiently produced from a wide range of aliphatic α‐monosubstituted aldehydes, with high functional‐group tolerance.
Augustin Nouaille, Emmanuel Magnier, Corinne Gosmini, Guillaume Dagousset   +3 more
wiley   +1 more source

Shedding Light on Synthetic Autocatalysis: From Conventional Closed‐Shell Chemistries to Overlooked Open‐Shell Occurrences

Chemistry – A European Journal, EarlyView.
Why add another catalyst when the product itself holds the power to catalyze its own formation? Autocatalysis in synthetic chemistry enhances reaction efficiency and uncovers novel catalytic behavior across both closed‐shell and open‐shell systems, expanding reactivity and enabling innovative design strategies.
Jaspreet Kaur, Joshua P. Barham
wiley   +1 more source