Search Results - "Walton, John C."

The Oxime Portmanteau Motif: Released Heteroradicals Undergo Incisive EPR Interrogation and Deliver Diverse Heterocycles by Walton, John C

“…Selective syntheses are now available for compounds of many classes, based on C-centered radicals, exploiting a diverse range of mechanisms. The prospect for…”
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Functionalised Oximes: Emergent Precursors for Carbon-, Nitrogen- and Oxygen-Centred Radicals by Walton, John C

“…Oxime derivatives are easily made, are non-hazardous and have long shelf lives. They contain weak N-O bonds that undergo homolytic scission, on appropriate…”
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Synthetic Strategies for 5- and 6-Membered Ring Azaheterocycles Facilitated by Iminyl Radicals by Walton, John C

“…The totality of chemical space is so immense that only a small fraction can ever be explored. Computational searching has indicated that bioactivity is…”
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Free Radical Mediated Oxidative Degradation of Carotenes and Xanthophylls by Mordi, Raphael C, Ademosun, Olabisi T, Ajanaku, Christiana O, Olanrewaju, Ifedolapo O, Walton, John C

“…This article reviews the excited-state quenching, pro-vitamin A activity and anticarcinogenicity of carotenes and xanthophylls in relation to their chemical…”
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Dissociation or Cyclization: Options for a Triad of Radicals Released from Oxime Carbamates by McBurney, Roy T, Walton, John C

“…A set of oxime carbamates having N-alkyl and N,N-dialkyl substituents were prepared via carbonyldiimidazole intermediates. It was shown by EPR spectroscopy…”
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EPR Studies on the Addition of Ligated Boryl Radicals to Carbonyl Compounds by Walton, John C, Dai, Wen, Curran, Dennis P

“…The boron-centered radicals derived from alkenyl N-heterocyclic carbene (NHC)-boranes bearing ester substituents were recently found to ring close in 5-endo…”
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Linking Borane with N-Heterocyclic Carbenes: Effective Hydrogen-Atom Donors for Radical Reactions by Walton, John C

“…Undue influence: N-heterocyclic carbenes (NHCs) were found to reduce the strength of the B---H bonds of borane by a surprisingly large amount upon the…”
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5-Endo Cyclizations of NHC-Boraallyl Radicals Bearing Ester Substituents: Characterization of Derived 1,2-Oxaborole Radicals and Boralactones by Dai, Wen, McFadden, Timothy R, Curran, Dennis P, Früchtl, Herbert A, Walton, John C

“…EPR studies of radical hydrogen abstraction reactions of N-heterocyclic carbene (NHC) complexes of alkenylboranes bearing two ester substituents revealed not…”
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Generation and Structure of Unique Boriranyl Radicals by Walton, John C, McFadden, Timothy R, Curran, Dennis P

“…Three-member ring boracyclopropanes (boriranes) with N-heterocyclic carbene substituents were prepared by a recently discovered route. H atoms were selectively…”
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N-Heterocyclic Carbene Boryl Radicals: A New Class of Boron-Centered Radical by Ueng, Shau-Hua, Solovyev, Andrey, Yuan, Xinting, Geib, Steven J, Fensterbank, Louis, Lacôte, Emmanuel, Malacria, Max, Newcomb, Martin, Walton, John C, Curran, Dennis P

“…Reduction of xanthates by N-heterocyclic carbene boranes (NHC-boranes) has been suggested to occur by a radical chain mechanism involving heretofore unknown…”
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Microhydration and the Enhanced Acidity of Free Radicals by Walton, John C

“…Recent theoretical research employing a continuum solvent model predicted that radical centers would enhance the acidity (RED-shift) of certain proton-donor…”
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Preparative semiconductor photoredox catalysis: An emerging theme in organic synthesis by Manley, David W, Walton, John C

“…Heterogeneous semiconductor photoredox catalysis (SCPC), particularly with TiO2, is evolving to provide radically new synthetic applications. In this review we…”
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EPR and Preparative Studies of 5-endo Cyclizations of Radicals Derived from Alkenyl NHC-Boranes Bearing tert-Butyl Ester Substituents by Dai, Wen, Curran, Dennis P, Walton, John C

“…Radical H atom abstraction from a set of N-heterocyclic carbene (NHC) complexes of alkenylboranes bearing two tert-butyl ester substituents was studied by EPR…”
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EPR Studies of the Generation, Structure, and Reactivity of N-Heterocyclic Carbene Borane Radicals by Walton, John C, Brahmi, Malika Makhlouf, Fensterbank, Louis, Lacôte, Emmanuel, Malacria, Max, Chu, Qianli, Ueng, Shau-Hua, Solovyev, Andrey, Curran, Dennis P

“…N-Heterocyclic carbene boranes (NHC−boranes) are a new “clean” class of reagents suitable for reductive radical chain transformations. Their structures are…”
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Unconventional Titania Photocatalysis: Direct Deployment of Carboxylic Acids in Alkylations and Annulations by Manley, David W, McBurney, Roy T, Miller, Phillip, Howe, Russell F, Rhydderch, Shona, Walton, John C

“…Under dry, anaerobic conditions, TiO2 photocatalysis of carboxylic acid precursors resulted in carbon–carbon bond-forming processes. High yields of dimers were…”
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Microwave-Promoted Syntheses of Quinazolines and Dihydroquinazolines from 2-Aminoarylalkanone O-Phenyl Oximes by Portela-Cubillo, Fernando, Scott, Jackie S, Walton, John C

“…A wide range of biologically active compounds contain the quinazoline ring system. A new free-radical-based method of making functionalized quinazolines is…”
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Titania-Promoted Carboxylic Acid Alkylations of Alkenes and Cascade Addition–Cyclizations by Manley, David W, McBurney, Roy T, Miller, Phillip, Walton, John C, Mills, Andrew, O’Rourke, Christopher

“…Photochemical reactions employing TiO2 and carboxylic acids under dry anaerobic conditions led to several types of C–C bond-forming processes with…”
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Microwave-Assisted Syntheses of N-Heterocycles Using Alkenone-, Alkynone- and Aryl-carbonyl O-Phenyl Oximes: Formal Synthesis of Neocryptolepine by Portela-Cubillo, Fernando, Scott, Jackie S, Walton, John C

“…This research aimed to provide a new and “clean” synthetic method that would enable both known and novel N-heterocycles to be prepared efficiently. O-Phenyl…”
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Electron Paramagnetic Resonance and Computational Studies of Radicals Derived from Boron-Substituted N-Heterocyclic Carbene Boranes by Walton, John C, Brahmi, Malika Makhlouf, Monot, Julien, Fensterbank, Louis, Malacria, Max, Curran, Dennis P, Lacôte, Emmanuel

“…Fifteen second-generation NHC-ligated boranes with aryl and alkyl substituents on boron were prepared, and their radical chemistry was explored by electron…”
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Tethered 1,2-Si-Group Migrations in Radical-Mediated Ring Enlargements of Cyclic Alkoxysilanes: An EPR Spectroscopic and Computational Investigation by Walton, John C, Kanada, Ryutaro, Iwamoto, Takeaki, Shuto, Satoshi, Abe, Hiroshi

“…5- to 6-member ring enlargements of 3-oxa-2-silacyclopentylmethyl to 4-oxa-3-silacyclohexyl radicals were investigated by EPR spectroscopy and QM computations…”
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