Results 321 to 330 of about 2,813,819 (368)

The 1,2,3-triazole ‘all-in-one’ ring system in drug discovery: a good bioisostere, a good pharmacophore, a good linker, and a versatile synthetic tool

Expert Opinion on Drug Discovery, 2022
Introduction The 1,2,3-triazole ring occupies an important space in medicinal chemistry due to its unique structural properties, synthetic versatility and pharmacological potential making it a critical scaffold.
Deniz Lengerli, Kübra İbiş, Yahya Nural, E. Banoglu   +3 more
semanticscholar   +1 more source

Unusual ring systems in organic chemistry

Naturwissenschaften, 1977
In this article several compounds with unusual ring systems are surveyed briefly. Saturated and unsaturated monocyclic compounds, polycyclic compounds, and unconventional aromatic systems are covered. The reasons for the interest of organic chemists in the unusual ring systems are discussed.
Hanack, Michael, Subramanian, L. R., Eymann, Wolfgang   +2 more
openaire   +3 more sources

Use of Tree-Ring Chemistry to Document Historical Ground-Water Contamination Events

, 1990
The annual growth rings of tulip trees (Liriodendron tulipifera L.) appear to preserve a chemical record of ground-water contamination at a landfill in Maryland.
D. Vroblesky, T. Yanosky
semanticscholar   +1 more source

Renaissance of Ring-opening Chemistry of Benzotriazoles: New Wine in an Old Bottle.

The chemical record, 2020
1,2,3-Benzotriazoles could undergo ring cleavage to form ortho-amino arenediazonium or α-diazo-imine species via a Dimroth-type equilibrium. Historically, the synthetic potential of this unique reactivity had remained underdeveloped.
Yuanhao Wang, Zhiguo Wang, Yefeng Tang
semanticscholar   +1 more source

Fused-Ring-Linked Covalent Organic Frameworks.

Journal of the American Chemical Society, 2022
The development of linkage chemistry in the research area of covalent organic frameworks (COFs) is fundamentally important for creating robust structures with high crystallinity and diversified functionality. We reach herein a new level of complexity and
Jie Feng, Yajun Zhang, Sheng-Hua Ma, Chen Yang, Zhi-Peng Wang, Sanyuan Ding, Yun Li, Wei Wang   +7 more
semanticscholar   +1 more source

The chemistry of (ring)Ru2+ (ring = tetramethylthiophene, p-cymene)

Organometallics, 1991
Described are the compounds ((ring)Ru(OTf){sub 2}){sub x}, where ring = 2,3,4,5-tetramethylthiophene (TMT, 1), and p-cymene (2). These electrophilic reagents serve as precursors to ((ring)RuL{sub 3}){sup 2+}, where L{sub 3} = (H{sub 2}O){sub 3}, (NH{sub 3}){sub 3}, and (PH{sub 3}){sub 3}. Solutions of 1 and 2 react with carbon monoxide to give (ring)Ru(
Edward A. Ganja, Thomas B. Rauchfuss, Charlotte L. Stern   +2 more
openaire   +2 more sources

Ring Transformations in Tetrazole Chemistry

Journal f�r Praktische Chemie/Chemiker-Zeitung, 1998
AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
openaire   +3 more sources

Chemistry of Pnictogen(III)—Nitrogen Ring Systems

ChemInform, 2007
AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
BALAKRISHNA, MS, EISLER, DJ, CHIVERS, T
openaire   +5 more sources

Ring expansion reactions in organonickel chemistry

Journal of the Chemical Society D: Chemical Communications, 1970
In contrast with the reactions of NiL4(L = tertiary phosphine), Ni(ButNC)4 reacts with (CF3)2CO and (CF3)2CNH to give five-membered-ring compounds (ButNC)2[graphic omitted](X = O or NH) in an almost stereoselective 3- to 5-ring transformation.
M. Green, A. Greco, S. K. Shakshooki, F. G. A. Stone   +3 more
openaire   +2 more sources

Cyclopentadienyl ring activation in organometallic chemistry and catalysis

Nature Reviews Chemistry, 2023
The cyclopentadienyl (Cp) ligand is a cornerstone of modern organometallic chemistry. Since the discovery of ferrocene, the Cp ligand and its various derivatives have become foundational motifs in catalysis, medicine and materials science. Although largely considered an ancillary ligand for altering the stereoelectronic properties of transition metal ...
Andrew VanderWeide, Demyan E. Prokopchuk
openaire   +2 more sources