Results 21 to 30 of about 2,396 (173)

Selective Degradation of Polyurethanes in Mixed Plastic Wastes via Ir‐Catalyzed Hydrogenolysis

Angewandte Chemie, EarlyView.
The selective degradation of polyurethanes in mixed plastic wastes with polyesters and polyamides was achieved using H2 as a reactant, enabling simultaneous recovery of diformamides and polyols arising from polyurethanes and separation of polyesters and polyamides without any degradation.
Yuto Yamada, Takanori Iwasaki, Shinji Tanaka, Kyoko Nozaki   +3 more
wiley   +2 more sources

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

Water, Alcohols, Amines, and Amides as Formal Hydrogen‐Atom‐Transfer Reagents Through Activation With Redox‐Active Lewis Acids

Angewandte Chemie, EarlyView.
Protic molecules containing strong O─H or N─H bonds typically resist hydrogen‐atom abstraction because of the high reactivity of the resulting heteroatom‐centered radicals. However, association of the protic molecules with redox‐active Lewis acids can provide powerful hydrogen‐atom donors or proton‐coupled‐electron‐transfer reagents.
Petra Vojáčková, Armido Studer
wiley   +2 more sources

An Enantioselective Alkene Aminoarylation to Form Chiral Indolines via Electrostatically‐Directed Palladium Catalysis

Angewandte Chemie, EarlyView.
Enantioselective aminoarylation of ortho‐allyl anilines is achieved under mild conditions. Key to success is the electrostatically‐directed nature of the key aminopalladation step, achieved by using the sulfonated chiral ligand sSPhos on palladium. A detailed study of electronic trends allows tuning of the sulfonamide protecting group to enable good ...
Max Kadarauch, Paul T. Jirsch, H. Erik Diepers, Hamzah Sharif, Robert J. Phipps   +4 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

Theoretical Calculation of Hammett Constants for Benzoic Acid and Its Derivatives Using AM1-DFT Method

Tikrit Journal of Pure Science
The Hammett equation constants were calculated theoretically by statistically correlating the practical Hammett equation constants for these compounds with several theoretically calculated structural properties.
Abdullah Ramadan Ali, Faiz M. Hamid
doaj   +1 more source

Redox Potential Tuning of s-Tetrazine by Substitution of Electron-Withdrawing/Donating Groups for Organic Electrode Materials

Molecules, 2021
Herein, we tune the redox potential of 3,6-diphenyl-1,2,4,5-tetrazine (DPT) by introducing various electron-donating/withdrawing groups (methoxy, t-butyl, H, F, and trifluoromethyl) into its two peripheral benzene rings for use as electrode material in a
Dong Joo Min, Kyunam Lee, Hyunji Park, Ji Eon Kwon, Soo Young Park   +4 more
doaj   +1 more source

From Berzelius to Hyperspace: Previously Unrecognized Network of Reactivity in Textbook Brominations

Angewandte Chemie, EarlyView.
Robotic scans across multidimensional condition spaces of classic bromination reactions uncover regions of previously unrecognized reactivity, yielding new major products and novel substitution patterns. Correlation and anticorrelation analyses of product distributions across these hyperspaces enable reconstruction of the underlying mechanistic ...
Yankai Jia, Wai‐Shing Wong, Yasemin Bilgi‐Gadina, Louis P. J.‐L. Gadina, King‐Lam Kwong, Yanqiu Jiang, Nikolaos Vagkidis, Benito Marazzi, Peter R. Schreiner, Bartosz A. Grzybowski   +9 more
wiley   +2 more sources

Synthesis, Acidity Constants and Tautomeric Structure of the Diazonium Coupling Products of 2-(Benzylsulfanyl)-7H-purin-6-one in Its Ground and Excited States

Molecules, 2011
A series of new 8-arylhydrazono-2-(benzylsulfanyl)-7H-purin-6-ones 6 were synthesized, their electronic absorption spectra in different organic solvents of varying polarities were investigated and their acid dissociation constants in both the ground and ...
Hosam A. Saad, Farag M. Altalbawy, Elham S. Darwish, Mosselhi A. Mosselhi   +3 more
doaj   +1 more source