Results 81 to 90 of about 55,156 (263)

A DFT Study on the Mechanism of Selective Formation of Substituted Azepines From 1‐Azabutadienes and Cyclopropanes

Chemistry – A European Journal, EarlyView.
The origin of the unusual regioselectivity in the Mg‐catalyzed cyclization of azadiene‐type imines with cyclopropanes is elucidated by DFT calculations. Although five‐membered rings are typically favored, energy decomposition analysis reveals that severe steric congestion induces a highly distorted transition state, rendering the five‐membered pathway ...
Ryo Kobayashi, Chao Wang, Shuto Kosuge, Yuji Matsuya, Kenji Sugimoto, Keiichi Hirano   +5 more
wiley   +1 more source

Phosphoramidite Gold(I)-Catalyzed Diastereo- and Enantioselective Synthesis of 3,4-Substituted Pyrrolidines [PDF]

, 2011
In this article the utility of phosphoramidite ligands in enantioselective AuI catalysis was explored in the development of highly diastereo- and enantioselective AuI-catalyzed cycloadditions of allenenes.
Benitez, Diego, Goddard, William A., III, González, Ana Z., Tkatchouk, Ekaterina, Toste, F. Dean   +4 more
core   +3 more sources

Monosubstituted N‐Arylhydroxylamine Chemistry: Integrating Contemporary Synthetic Approaches for the Efficient Construction of Diverse Heterocyclic Scaffolds

Chemistry – A European Journal, EarlyView.
Monosubstituted N‐arylhydroxylamines represent a unique subclass of hydroxylamines that act as pivotal intermediates in redox transformations and as versatile platforms for further synthetic transformations. They serve as key building blocks in the synthesis of architecturally complex heterocycles and other valuable organic compounds.
Michael G. Kallitsakis, Kyriakos D. Nikopoulos, Ioannis N. Lykakis   +2 more
wiley   +1 more source

Fluorescence of 8-Acyl-1-Pyrrolidinylnaphthalenes

Photochem
Four 8-acyl-1-pyrrolidinylnaphalenes are prepared where the acyl group is pivaloyl (6), benzoyl (7), benzyloxycarbonyl (8), and ethyloxycarbonyl (9). Crystal structures for 6–8 show that both the carbonyl and pyrrolidinyl groups are nearly perpendicular ...
Angela Liao, Lucas Teuber, Robert Pike, Christopher Abelt   +3 more
doaj   +1 more source

Crystal structure of methyl 3′-benzamido-4′-(4-methoxyphenyl)-1′-methylspiro[indeno[1,2-b]quinoxaline-11,2′-pyrrolidine]-3′-carboxylate

Acta Crystallographica Section E: Crystallographic Communications, 2016
In the title compound, C35H30N4O3, the spiro C atom connects the five-membered pyrrolidine ring and the indenoquinoxaline ring system. The pyrrolidine ring adopts a twist conformation. An intramolecular N—H...N interaction between the amino group and the
Kuppan Chandralekha, Adukamparai Rajukrishnan Sureshbabu, Deivasigamani Gavaskar, Srinivasakannan Lakshmi   +3 more
doaj   +1 more source

Ionization effects on the partitioning behavior of food and beverage aroma compounds between aqueous phases and air and organic matrices [PDF]

, 2011
Aroma compounds in the Flavornet database were screened for ionizable functional groups such as carboxylic acids, aliphatic and aromatic amines, phenols, alcohols, and thiols.
Kaya Forest, Sierra Rayne
core   +2 more sources

Enzymatic Prenylation of Proteins and Peptides: From Cysteine S‐Prenylation to Tryptophan‐Selective Biocatalysis

Chemistry – A European Journal, EarlyView.
This review highlights biocatalytic prenylation as a versatile strategy for tailoring the functional properties of peptides and proteins. By comparing branched isoprenoids with linear lipids, we illustrate how specific prenyl architectures modulate the behaviors of lipidated proteins within membrane environments.
Daisuke Fujinami, Hikari Ozawa, Sohei Ito   +2 more
wiley   +1 more source

(2RS,3aRS,9aRS)-3a-Methyl-2-phenyl-3,3a,9,9a-tetrahydro-1H-benzo[f]indol-4(2H)-one Hydrobromide

Molbank
(2RS,3aRS,9aRS)-3a-methyl-2-phenyl-3,3a,9,9a-tetrahydro-1H-benzo[f]indol-4(2H)-one hydrobromide was first synthesized via a tandem aza-Cope rearrangement and Mannich reaction from (1RS,2SR)-2-amino-1-(prop-1-en-2-yl)-2,3-dihydro-1H-inden-1-ol, which, in ...
Denis A. Tiunov, Victor A. Tafeenko, Alexander V. Kurkin   +2 more
doaj   +1 more source

Crystal structure of ethyl 1′,5-dimethyl-2′′,3-dioxo-3H-dispiro[benzo[b]thiophene-2,3′-pyrrolidine-2′,3′′-indoline]-4′-carboxylate

Acta Crystallographica Section E: Crystallographic Communications, 2015
The title compound, C23H22N2O4S, crystallized with two independent molecules (A and B) in the asymmetric unit. They have very similar conformations with the pyrrolidine ring having a twisted conformation, on the Cspiro—Cspiro bond, in both molecules.
R. Raja, J. Govindaraj, M. Suresh, R. Raghunathan, A. SubbiahPandi   +4 more
doaj   +1 more source

Using EGA-GC to Analyze Nicotine N-oxide in Order to Explain Low Nicotine Concentrations in E-cigarette Liquids [PDF]

, 2018
Evolved-gas analysis coupled with gas chromatography (EGA-GC) was used to analyze e-cigarette liquids. Previous analyses of e-cigarette liquids have shown that the determined concentration of nicotine is lower than the advertised concentration.
Wuerch, Cory
core   +1 more source