76
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NajeebUllah M, Knight DW, Munawar MA, Yaseenx M, Vincenzo F. A microwave-assisted synthesis of triphenodioxazines [TPDOs]. Tetrahedron 2010. [DOI: 10.1016/j.tet.2010.06.085] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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77
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Hayes SJ, Knight DW, Smith AW, O’Halloran MJ. Erratum to “On the curious oxidations of 2-furylethanols” [Tetrahedron Lett. 51 (2010) 720–723]. Tetrahedron Lett 2010. [DOI: 10.1016/j.tetlet.2010.02.086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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78
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Gottlieb HB, Knight DW, Ji L, Cunningham JT. Oropharyngeal regulation of urine output and cardiovascular function in rats with osmotic stimulation by sham ingestion. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.1025.18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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79
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Meenakshisundaram S, Nowicka E, Miedziak PJ, Brett GL, Jenkins RL, Dimitratos N, Taylor SH, Knight DW, Bethell D, Hutchings GJ. Oxidation of alcohols using supported gold and gold–palladium nanoparticles. Faraday Discuss 2010. [DOI: 10.1039/b908172k] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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80
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Hayes SJ, Knight DW, Smith AW, O’Halloran MJ. On the curious oxidations of 2-furylethanols. Tetrahedron Lett 2010. [DOI: 10.1016/j.tetlet.2009.11.119] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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81
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Hayes SJ, Knight DW, Smith AW, O’Halloran MJ. A general route to 5-substituted-2-furylacetic acids: a brief synthesis of plakorsin B. Tetrahedron Lett 2010. [DOI: 10.1016/j.tetlet.2009.11.120] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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82
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83
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Côte M, Nicholls T, Knight DW, Morgan IR, Rogueda PGA, King SM, Heenan RK, Griffiths PC. Self-assembling chiral gelators for fluorinated media. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:8678-8684. [PMID: 19402688 DOI: 10.1021/la804277z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Formulations involving partially and fully fluorinated media represent a technological challenge given the lipophobic and hydrophobic nature of such liquids. The identification of self-associating materials with which to control the viscosity and solubilizing characteristics of fluorinated solvents is a particularly interesting area of research. It is shown here that the presence of the stereogenic centers inherent in a family of bis-(alpha,beta-dihydroxy ester)s is an essential requirement for the thermoreversible gelation of mixtures of partially fluorinated liquids 2H,3H-perfluoropentane (HPFP) and 1H,1H-heptafluorobutanol (HFB). Gelation is driven by hydrogen bonding, which induces a nonpreferred conformation around the bis-(alpha,beta-dihydroxy ester) structural motif. An analysis of the melting temperature yields an enthalpy of melting that is consistent with three to four hydrogen bonds, commensurate with the end-group structure of the gelator. Small-angle neutron scattering demonstrated the existence of the common fibrillar structures whose dimensions showed no obvious correlation with the molecular structure of the gelator.
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84
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85
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Sankar M, Dimitratos N, Knight DW, Carley AF, Tiruvalam R, Kiely CJ, Thomas D, Hutchings GJ. Oxidation of glycerol to glycolate by using supported gold and palladium nanoparticles. CHEMSUSCHEM 2009; 2:1145-1151. [PMID: 19830778 DOI: 10.1002/cssc.200900133] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Glycolic acid is an important chemical that has uses as a cleaning agent as well as a chemical intermediate. At present glycolic acid is manufactured from either chloroacetic acid or from formaldehyde hydrocyanation, both routes being nongreen and using nonsustainable resources. We investigate the possibility of producing glycolate from the oxidation of glycerol, a sustainable raw material. We show that by using 1 % wt Au/carbon catalysts prepared using a sol-immobilization method glycolate yields of ca. 60 % can be achieved, using hydrogen peroxide as oxidant in an autoclave reactor. We describe and discuss the reaction mechanism and consider the reaction conditions that maximize the formation of glycolate.
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86
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Miller DJ, Yu F, Knight DW, Allemann RK. 6- and 14-Fluoro farnesyl diphosphate: mechanistic probes for the reaction catalysed by aristolochene synthase. Org Biomol Chem 2009; 7:962-75. [DOI: 10.1039/b817194g] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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87
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Dimitratos N, Lopez-Sanchez JA, Anthonykutty JM, Brett G, Carley AF, Tiruvalam RC, Herzing AA, Kiely CJ, Knight DW, Hutchings GJ. Oxidation of glycerol using gold–palladium alloy-supported nanocrystals. Phys Chem Chem Phys 2009; 11:4952-61. [DOI: 10.1039/b904317a] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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88
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Knight DW, Morgan IR. An optimised and recoverable tartrate surrogate for sharpless asymmetric epoxidations. Tetrahedron Lett 2009. [DOI: 10.1016/j.tetlet.2008.10.069] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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89
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Xu C, Bartley JK, Enache DI, Knight DW, Lunn M, Lok M, Hutchings GJ. On the synthesis of β-keto-1,3-dithianes from conjugated ynones catalyzed by magnesium oxide. Tetrahedron Lett 2008. [DOI: 10.1016/j.tetlet.2008.02.030] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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90
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Dunford D, Guyader M, Jones S, Knight DW, Hursthouse MB, Coles SJ. On the highly stereoselective addition of lithio-acetylides to α-hydroxy-ketones. Tetrahedron Lett 2008. [DOI: 10.1016/j.tetlet.2008.02.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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91
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Evans AB, Flügge S, Jones S, Knight DW, Tan WF. A new synthesis of the F5 furan fatty acid and a first synthesis of the F6 furan fatty acid. ARKIVOC 2008. [DOI: 10.3998/ark.5550190.0009.a08] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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92
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Bew SP, El-Taeb GMM, Jones S, Knight DW, Tan WF. Expedient Syntheses of β-Iodofurans by 5-endo-dig Cyclisations. European J Org Chem 2007. [DOI: 10.1002/ejoc.200700681] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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93
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Hayes SJ, Knight DW, Menzies MD, O’Halloran M, Tan WF. An efficient furan synthesis using heterogeneous catalysis. Tetrahedron Lett 2007. [DOI: 10.1016/j.tetlet.2007.08.102] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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94
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Bainbridge NP, Currie AC, Cooper NJ, Muir JC, Knight DW, Walton JM. On the use of anomeric hydroxylamines in the reverse-Cope cyclisation. Tetrahedron Lett 2007. [DOI: 10.1016/j.tetlet.2007.09.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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95
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Knight DW, Rost HC, Sharland CM, Singkhonrat J. A general approach to polysubstituted pyrroles. Tetrahedron Lett 2007. [DOI: 10.1016/j.tetlet.2007.08.097] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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96
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Jones AD, Redfern AL, Knight DW, Morgan IR, Williams AC. Selenocyclisations of homoallylic sulfonamides: stereoselective methods for the elaboration of substituted pyrrolidines, pyrrolines and derivatives. Tetrahedron 2006. [DOI: 10.1016/j.tet.2006.07.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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97
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Li G, Enache DI, Edwards J, Carley AF, Knight DW, Hutchings GJ. Solvent-free oxidation of benzyl alcohol with oxygen using zeolite-supported Au and Au–Pd catalysts. Catal Letters 2006. [DOI: 10.1007/s10562-006-0083-1] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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98
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Proctor AJ, Beautement K, Clough JM, Knight DW, Li Y. Chromatography-free product separation in the Mitsunobu reaction. Tetrahedron Lett 2006. [DOI: 10.1016/j.tetlet.2006.05.070] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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99
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Amjad M, Knight DW. On the rapid synthesis of highly substituted proline analogues by 5-endo-trig iodocyclisation. Tetrahedron Lett 2006. [DOI: 10.1016/j.tetlet.2006.02.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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100
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Enache DI, Edwards JK, Landon P, Solsona-Espriu B, Carley AF, Herzing AA, Watanabe M, Kiely CJ, Knight DW, Hutchings GJ. Solvent-Free Oxidation of Primary Alcohols to Aldehydes Using Au-Pd/TiO2 Catalysts. Science 2006; 311:362-5. [PMID: 16424335 DOI: 10.1126/science.1120560] [Citation(s) in RCA: 1322] [Impact Index Per Article: 73.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The oxidation of alcohols to aldehydes with O2 in place of stoichiometric oxygen donors is a crucial process for the synthesis of fine chemicals. However, the catalysts that have been identified so far are relatively inactive with primary alkyl alcohols. We showed that Au/Pd-TiO2 catalysts give very high turnover frequencies (up to 270,000 turnovers per hour) for the oxidation of alcohols, including primary alkyl alcohols. The addition of Au to Pd nanocrystals improved the overall selectivity and, using scanning transmission electron microscopy combined with x-ray photoelectron spectroscopy, we showed that the Au-Pd nanocrystals were made up of a Au-rich core with a Pd-rich shell, indicating that the Au electronically influences the catalytic properties of Pd.
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