Results 71 to 80 of about 36,678 (260)

2H-furano [2,3-c] pyrazole heterocyclic system synthesis. [PDF]

, 2015
Pyrazoles are one of the most important heterocyclic compounds as they have various pharmacological and biological activities. Condensed pyrazole derivatives exhibit significant biological properties such as anti-flamatory, antibacterial, antispasmodic ...
Paulavičiūtė, Rūta,
core   +1 more source

Two tautomers in the same crystal: 3-(4-fluorophenyl)-1H-pyrazole and 5-(4-fluorophenyl)-1H-pyrazole

Acta Crystallographica Section E, 2014
The title co-crystal, 3-(4-fluorophenyl)-1H-pyrazole–5-(4-fluorophenyl)-1H-pyrazole (1/1), C9H7FN2, crystallizes with four independent molecules (A, B, C and D) in the asymmetric unit exhibiting two tautomeric forms (A and D; B and C) due to N—H proton ...
Thammarse S. Yamuna, Manpreet Kaur, Jerry P. Jasinski, Brian J. Anderson, H. S. Yathirajan   +4 more
doaj   +1 more source

Ullmann‐Type N‐Heteroarylation of Nitrogen Heterocycles Catalyzed by Heterogeneous CuNPs/HKUST‐1

EcoEnergy, EarlyView.
A practical strategy for the direct synthesis of CuNPs/HKUST‐1 heterogeneous catalyst was developed and used for the catalyzing Ullmann‐type N‐arylation of N‐heterocycles with high yields, excellent recyclability, and low copper leaching. ABSTRACT Ullmann‐type C–N coupling is an essential reaction to construct functional nitrogen heterocycles, whereas ...
Shuai Yang, Fangshu Han, Yamin Dong, Liangting Wu, Wenchao Tang, Changyan Guo, Jide Wang, Ablimit Abdukader, Chenjiang Liu, Yonghong Zhang   +9 more
wiley   +1 more source

The Serendipitous Discovery of Rollover Cyclometalation: From Unrecognized Observation to Transformative Chemistry

European Journal of Inorganic Chemistry, EarlyView.
Rollover cyclometalation is a distinctive variant of classical cyclometalation where a chelated heterocyclic ligand undergoes internal rotation, releasing one donor atom from coordination and subsequently activating a remote C─H bond with high regioselectivity.
Antonio Zucca, Maria I. Pilo
wiley   +1 more source

(E)-1-(3,4-Dimethoxyphenyl)-3-(1,3-diphenyl-1H-pyrazol-4-yl)prop-2-en-1-one

IUCrData
In the title compound, C26H22N2O3, the dihedral angle between the benzene and pyrazole rings of the chalcone unit is 88.3 (1)°. The pyrazole ring has two attached phenyl rings that form dihedral angles with the pyrazole ring of 22.6 (2) and 40.0 (1)°. In
Jiha Sung
doaj   +1 more source

3,4,5,6,7,8,9-Heptachlorophenaleno[1,9-bc]pyrazole

, 2009
Treatment of perchloro-7H-cyclopropano[a]acenaphthylene 1 with hydrazine hydrate in DMF at ca. 80 °C gives the new 3,4,5,6,7,8,9-heptachlorophenaleno[1,9-bc]pyrazole 2 in 69% yield.
Polina K. Demetriadou, Panayiotis A. Koutentis, Panayiotis Koutentis, Polina Demetriadou   +3 more
core   +1 more source

Enantioselective Conjugate Addition of Malononitriles to Enynes: A Stereodivergent Approach to Chiral Allenes

European Journal of Organic Chemistry, EarlyView.
Quinine‐catalyzed enantioselective conjugate addition of malononitrile derivatives to enynes provides trisubstituted chiral allenes in good to excellent yields and high enantiopurities under mild conditions. Broad substrate scope, easy scalability, and versatile post‐synthetic transformations into enantioenriched pyrazoles and furans highlight the ...
Martin Kamlar, Josef Panenka, Ivana Císařová, Jan Veselý   +3 more
wiley   +1 more source

Navigating the Radical Oxo‐Functionalization of Alkenes Toward Ketones

European Journal of Organic Chemistry, EarlyView.
Straightforward access to complex ketones in a single synthetic step: This Review surveys the latest advances in three‐component alkene 1,2‐oxo‐functionalizations. The opportunities unlocked by the so‐called single‐electron (1e–) logic, including access to a broad pool of radical precursors and carbonyl oxygen atom sources, are highlighted.
Mattia Lepori, Luigi Dolcini, Alexander Bell, Joshua P. Barham   +3 more
wiley   +1 more source

Microwave versus ultrasound assisted synthesis of some new heterocycles based on pyrazolone moiety

Journal of Saudi Chemical Society, 2010
Different pyrazolone derivatives were prepared by microwave irradiation and ultrasound assisted methods besides the traditional ones. They were used for synthesis of some derivatives of spiropiperidine-4,4′-pyrano[2,3-c]pyrazole, dihydropyrano[2,3-c ...
Aamal A. Al-Mutairi, Fatma E. M. El-Baih, Hassan M. Al-Hazimi   +2 more
doaj   +1 more source

Tandem Synthesis and Photophysical Behavior of Pyrazolo[3,4‐h][1,6]naphthyridines: A Theoretical–Experimental Approach

European Journal of Organic Chemistry, EarlyView.
A tandem reaction of 5‐aroylpyrazolo[3,4‐b]pyridines with malononitrile and methanol to access pyrazolo[3,4‐h][1,6]naphthyridines was achieved in 60%–66% yield under microwave conditions. The tricyclic fluorophoric core bears groups of different stereoelectronic nature (i.e., alkyl, aryl, MeO, and CN), and thus their optoelectronic activity shows ...
Carlos Cifuentes, Alexander Ladino‐Bejarano, Cristian Rivera‐Moyano, Jaime Portilla   +3 more
wiley   +1 more source