Browsing Chemistry (Scholarly Publications) by Author "CONNON, STEPHEN"
Now showing items 1-20 of 29
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Aerobic oxidation of NHC-catalysed aldehyde esterifications with alcohols: Benzoin, not the Breslow intermediate, undergoes oxidation
CONNON, STEPHEN (2013)Benzoin (and neither the Breslow intermediate nor the NHC–aldehyde tetrahedral adduct) has been unambiguously identified as the oxidised species in aerobic NHC-catalyse d aldehyde esterifications. -
Asymmetric acyl-transfer promoted by readily assembled chiral 4-N,N-dialkylaminopyridine derivatives
CONNON, STEPHEN; MC CABE, THOMAS; WATSON, GRAEME WILLIAM (Royal Society of Chemistry, 2006)The development of a new class of chiral 4-N,N-dialkylaminopyridine acyl-transfer catalysts capable of exploiting both van der Waals (?) and H-bonding interactions to allow remote chiral information to stereochemically ... -
Asymmetric catalysis with bifunctional cinchona alkaloid-based urea and thiourea organocatalysts
CONNON, STEPHEN (2008)Cinchona alkaloid derivatives modified to include a (thio)urea component have emerged in the last three years as readily accessible, robust and tunable bifunctional organocatalysts for a range of synthetically useful ... -
Asymmetric organocatalytic reductions mediated by dihydropyridines
CONNON, STEPHEN (Royal Society of Chemistry, 2007)Catalytic asymmetric reduction reactions have long been the preserve of the transition metal catalyst. Inspired by the myriad efficient enzyme-catalysed reduction reactions routine in biological systems, chemists have ... -
Catalytic (asymmetric) methylene transfer to aldehydes
CONNON, STEPHEN; KAVANAGH, SARAH (2010)An investigation into the poor activity of sulfides as catalysts for sulfonium-ylide-mediated methylene transfer to aldehydes has indicated that ylide formation is the problematic catalytic cycle step. Alkylation with ... -
Catalytic, enantio- and diastereoselective synthesis of gamma-butyrolactones incorporating quaternary stereocentres
CONNON, STEPHEN (2012)A new, highly enantio- and diastereoselective catalytic asymmetric formal cycloaddition of aryl succinic anhydrides and aldehydes which generates paraconic acid (y-butyrolactone) derivatives is reported. -
Chemoselective crossed acyloin condensations: catalyst and substrate control
CONNON, STEPHEN (2011)The interplay between catalyst and substrate control in crossed acyloin condensation reactions has been studied. It was found that a pentafluorophenyl-substituted triazolium ion derived catalyst was capable of catalyzing ... -
Concise synthesis and CDK/GSK inhibitory activity of the missing 9-azapaullones
CONNON, STEPHEN; GRAYSON, DAVID; POWER, DAVID PATRICK (2010)A remarkably concise, chromatography-free route to the parent compound of the paullone family of cyclin-dependent kinase (CDK) inhibitors is reported. A similar strategy allowed the synthesis of the hitherto missing ... -
A DFT mechanistic study of the organocatalytic asymmetric reaction of aldehydes and homophthalic anhydride
ROZAS, ISABEL; CONNON, STEPHEN; Trujillo, Cristina; Botte, Astrid (2017)The first DFT study of the cycloaddition of benzaldehyde with homophthalic anhydride under the influence of a bifunctional organocatalyst is reported. The catalyst first binds and then deprotonates the anhydride, leading ... -
The enantioselective benzoin condensation promoted by chiral triazolium precatalysts: stereochemical control via hydrogen bonding.
CONNON, STEPHEN (2009)The design of a new class of triazolium ion precatalysts incorporating protic substituents is described. These materials promote the enantioselective benzoin condensation of a range of aromatic aldehydes (1?62% ee). ... -
Highly chemoselective direct crossed aliphatic- aromatic acyloin condensations with triazolium-derived carbene catalysts
CONNON, STEPHEN; GUNDALA , SIVAJI (2011)It has been shown for the first time that triazolium pre-catalysts promote (in the presence of base) highly chemoselective crossed acyloin condensation reactions between aliphatic and ortho-substituted aromatic aldehydes. ... -
Highly enantioselective ylide-mediated synthesis of terminal epoxides
CONNON, STEPHEN (2012)The highly efficient asymmetric epoxidation of aldehydes by methylene transfer is now possible using new sulfonium salts -
Highly recyclable, imidazolium derived ionic liquids of low antimicrobial and antifungal toxicity: A new strategy for acid catalysis
MYLES, LAUREN; CONNON, STEPHEN (2010)Imidazolium derived ionic liquid catalysts have been developed which are aprotic and of low antimicrobial and antifungal toxicity, yet which can act as efficient Br?nsted acidic catalysts in the presence of protic additives. ... -
Highly tunable arylated cinchona alkaloids as bifunctional catalysts
CONNON, STEPHEN (2012)We report the design and evaluation of a library of chiral bifunctional organocatalysts in which the distance between the catalytically active units can be systematically varied. -
The immobilisation of chiral organocatalysts on magnetic nanoparticles: the support particle cannot always be considered inert.
GOUNKO, IOURI; CONNON, STEPHEN (2011)A systematic study concerning the immobilisation onto magnetic nanoparticles of three useful classes of chiral organocatalyst which rely on a confluence of weak, easily perturbed van der Waals and hydrogen bonding interactions ... -
Kinetic resolution of sec-alcohols using a new class of readily assembled (S)-proline-derived 4-(pyrrolidino)-pyridine analogues
CONNON, STEPHEN (2005)We report the development of a new class of readily prepared chiral 4-(pyrrolidino)-pyridine catalysts capable of exploiting both van der Waals (?) and H-bonding interactions, thus allowing remote chiral information to ... -
Microwave-assisted efficient thiolate-catalysed homo- and crossed intermolecular Tishchenko reactions
CONNON, STEPHEN; MANONI, FRANCESCO; CURRAN, SIMON (2011)Recently, the first efficient intermolecular crossed Tishchenko reactions were reported. The utility of these processes is curtailed by long reaction times of up to 4 days (at reflux). Herein we report that these reactions ... -
A new generation of aprotic yet Bronsted acidic imidazolium salts: effect of ester/amide groups in the C-2, C-4 and C-5 on antimicrobial toxicity and biodegradation
CONNON, STEPHEN (2013)Imidazolium Brønsted acidic catalysts substituted with ester/amides have been assessed for both antimicrobial toxicity and biodegradation. Low toxicity to a screen of 20 microbial strains (12 fungi and 8 bacteria) was ... -
A new generation of aprotic yet Bronsted acidic imidazolium salts: low toxicity, high recyclability and greatly improved activity
CONNON, STEPHEN (2013)Catalysts which have low antimicrobial toxicity and are aprotic, yet which can act as Brønsted acidic catalysts in the presence of protic additives have been developed. The catalysts are recyclable, considerably more active ... -
NHC-catalysed aerobic aldehyde-esterifications with alcohols: no additives or cocatalysts required
CONNON, STEPHEN (2013)A highly efficient, broad scope, additive-free mild protocol for the oxidative carbene-catalysed esterification of aldehydes (including the related aqueous oxidation to acids) has been developed