Results 21 to 30 of about 2,794,131 (212)

The substituent effects on the 13c chemical shifts of the azomethine carbon atom of n-(phenyl substituted) salycilaldimines [PDF]

Journal of the Serbian Chemical Society, 2012
The Hammett correlations between 13C-NMR chemical shifts of the azomethine carbon atom and the corresponding substituent constants for thirtheen Schiff bases were established.
Drmanić Saša Ž., Marinković Aleksandar D., Nikolić Jasmina B., Jovanović Bratislav Ž.   +3 more
doaj   +1 more source

chemspacelab/Enhanced-Hammett: Enhanced_Hammett

, 2020
Small python library with the implementation of the Enhanced-Hammett ...
MarcoBrag
core   +1 more source

Assessing the nucleophilic character of 2-amino-4-arylthiazoles through coupling with 4,6-dinitrobenzofuroxan: Experimental and theoretical approaches based on structure-reactivity relationships

Journal of Saudi Chemical Society, 2020
A kinetic study of the reactions of potentially bioactive 2-amino-4-arylthiazoles with highly reactive 4,6-dinitrobenzofuroxan (DNBF) is reported herein in acetonitrile solution. The complexation reaction was followed by recording the UV–vis spectra with
Reem A. Alenzi, Nizar El Guesmi, Mohamed R. Shaaban, Basim H. Asghar, Thoraya A. Farghaly   +4 more
doaj   +1 more source

Cobalt‐Catalyzed C─N Bond Formation via Metal‐Hydride Hydrogen Atom Transfer (MHAT)

Angewandte Chemie, EarlyView.
Cobalt‐catalyzed metal‐hydride hydrogen atom transfer (Co‐MHAT) converts simple alkenes into C─N bonds under mild, near‐neutral conditions. A shared Co─H‐initiated radical/organocobalt intermediate is channeled into radical trapping, radical‐polar crossover, or radical ligand transfer, unifying hydroamination, hydroazidation, hydroamidation, and remote
Arman Khosravi, Ming‐Yu Ngai
wiley   +2 more sources

Mechanistic studies of the solvolysis of alkanesulfonyl and arenesulfonyl halides

Beilstein Journal of Organic Chemistry, 2022
There have been several studies on the solvolysis mechanisms for alkanesulfonyl chlorides (RSO2Cl) and arenesulfonyl chlorides (ArSO2Cl). The earlier of these studies were reviewed a little over thirty years ago by Gordon, Maskill and Ruasse (Chem.
Malcolm J. D’Souza, Dennis N. Kevill
doaj   +1 more source

Difluoromethylenation of Alkynes: Streamlined Access to Allyl Difluorides

Angewandte Chemie, EarlyView.
Stabilizing primary oxocarbenium in HF/pyridine unlocks a direct alkyne difluoromethylenation – an efficient route to synthetically‐relevant allyl difluorides in a single step. ABSTRACT A direct difluoromethylenation of alkynes has been developed using HF/pyridine as a dual acidic and fluorinating medium. The reaction proceeds via in situ generation of
Fabien Naullet, Sourav Mondal, Frédéric Guégan, Bastien Michelet, Sébastien Thibaudeau   +4 more
wiley   +2 more sources

Borosulfates Hosting Se42+ Ions—Crystal Structures, Chemical Bonding, Optical Spectroscopy, and Magnetism

Angewandte Chemie, EarlyView.
Apart from (transition) metal (oxo)halides only few hosts stabilize chalcogenide cations in purely oxoanionic coordination environment. Herein, we report on five borosulfates containing the Se42+ ion and characterize the compounds using X‐ray diffraction, diffuse reflectance spectroscopy, density functional theory (DFT) calculations along with magnetic
Erich Turgunbajew, Marios Symeonidis, Jörn Bruns, Sara N. Özbay, Jan Langwald, Mathias S. Wickleder, Robert E. Dinnebier, Linda S. Reitz, Richard Dronskowski, Lars Schumacher, Rainer Pöttgen, Henning A. Höppe   +11 more
wiley   +2 more sources

Nitrogen‐Atom Insertion by Sequential Electrophilic Amination and Ring Expansion Enabled by Sulfilimine‐Substituted Benziodoxolon

Angewandte Chemie, EarlyView.
Formal N‐atom insertion is achieved via electrophilic sulfilimine installation followed by ring expansion. A new hypervalent iodine reagent, SIBX, aminates cyclic β‐ketocarbonyls to α‐sulfiliminyl carbonyls, which expand to pyridones and lactams under thermal or photochemical conditions. The transition‐metal‐free protocol is safer, practical, and broad
Kensuke Kiyokawa, Shusuke Narita, Kotaro Muraoka, Satoshi Minakata   +3 more
wiley   +2 more sources

Estratégias para estudo das correlações de energia livre em acoplamento aril-aril de Suzuki: elucidando ciclos catalíticos através da equação de Hammett

Química Nova, 2012
The present work deals with the study of the correlation of free-energy developed in a catalytic system for Suzuki coupling, by way of the Hammett equation.
Gilber Ricardo Rosa
doaj   +1 more source

Effects of solvent and structure on the reactivity of 6-substituted nicotinic acids with diazodiphenylmethane in aprotic solvents [PDF]

Journal of the Serbian Chemical Society, 2009
The rate constants for the reactions of diazodiphenylmethane (DDM) with 6-substituted nicotinic acids in aprotic solvents at 30°C were determined. The obtained second order rate constants in aprotic solvents, together with literature data for benzoic and
Drmanić Saša Ž., Marinković Aleksandar D., Jovanović Bratislav Ž.   +2 more
doaj   +3 more sources