Cross-Dehydrogenative Coupling Reactions With Redox-Active Guanidine Reagents. [PDF]
ChemistryABSTRACT Cross‐dehydrogenative coupling (CDC) reactions are attractive and environmentally friendly ways to form new C‐C and other element‐element bonds. Here, we report the first CDC reactions triggered by a redox‐active guanidine reagent. N‐phenyltetrahydroisoquinoline and derivatives with electron‐donating and withdrawing substituents at the N ...
Walter P, Hübner O, Himmel HJ.
europepmc +2 more sources
Excited state substituent constants: to Hammett or not? [PDF]
Structural Chemistry, 2011 In this study, an answer has been sought to several questions: Can substituents’ impact on the electronic properties of molecules in the excited singlet states be summed up by a set of substituent constants? Are the well known, ground state Hammett σ constants practical for this purpose? To answer these questions, the potentials and charges on atoms of
Sadlej-Sosnowska, Nina, Kijak, Michał
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Exchange Speed of Four-Component Nanorotors Correlates with Hammett Substituent Constants
Chemistry, 2021 Three distinct four-component supramolecular nanorotors were prepared, using, for the first time, bipyridine instead of phenanthroline stations in the stator.
Yi-Fan Li +4 more
doaj +1 more source
A comparative LFER study of the reactivity of pyridineacetic, pyridineacetic acids N-oxide and substituted phenylacetic acids with diazodiphenylmethane in various alcohols [PDF]
Journal of the Serbian Chemical Society, 2000 Rate constants have been determined for the reactions of diazodiphenylmethane (DDM) with 3- and 4-pyridineacetic acid, 3- and 4-pyridineacetic acid N-oxide and some meta- and para-substituted phenylacetic acids in twelve alcohols. The determined
Drmanić Saša Z. +2 more
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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. +3 more
doaj +1 more source
Designing Acid/Acid Co-Crystals through the Application of Hammett Substituent Constants
, 2016 The designed creation of co-crystals between substituted benzoic acids was investigated by the co-crystallization of 32 acid/acid combinations. Systems with differing signs of their Hammett substituent constants were found to successfully form co ...
Ghazala Sadiq (2321473) +4 more
core +6 more sources
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
Determination of Hammett Sigma Constants by Intramolecular Hydrogen Bonding [PDF]
Nature, 1958 THE extensive literature that exists concerning Hammett's σ-constants has been subjected to several recent reviews, including a compilation and examination of available data1, a discussion of the significance and limitations of the concepts involved2, and an attempt to deduce best values and probable errors for the σ-values3.
A. T. SHULGIN, A. W. BAKER
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A Theoretical Formulation of the Hammett Equation [PDF]
, 1952 A relation, which reduces to the form of Hammett\u27s equation, has been derived. Reactions which can be assumed to be of the form ion-dipole or dipole-dipole have been considered.
Gallup, Gordon A +5 more
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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 +4 more
wiley +2 more sources