01978nas a2200241   4500008004100000022001400041245011100055210006900166260009500235300001200330490000800342520104800350653002701398653002301425653003101448653002101479653004101500653001401541653001401555100001601569700002101585856013001606       2012                        eng d  a0021-951700aAminolysis of epoxides catalyzed by three-dimensional, mesoporous titanosilicates, Ti-SBA-12 and Ti-SBA-160 aAminolysis of epoxides catalyzed by threedimensional mesoporous   a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcSEP  a126-1400 v2933 a<p>The application of three-dimensional, mesoporous titanosilicates (Ti-SBA-12 and Ti-SBA-16) as reusable, solid catalysts for the synthesis of a range of beta-amino alcohols in high yields and selectivity through ring-opening of epoxides with amines at ambient and solvent-free conditions is reported, for the first time. These mesoporous titanosilicates (Si/Ti = 20-80) were prepared by a direct hydrothermal synthesis route adjusting the concentration of HCl (0.05-2 M) used in the synthesis. Ti ions in these catalysts were mostly substituted for Si in the framework. Water adsorption and Si-29 magic-angle spin nuclear magnetic resonance spectroscopy revealed that Ti-SBA-16 is more hydrophobic than Ti-SBA-12. Mesoporosity, three-dimensional architecture, surface hydrophobicity and easy access of Lewis acidic, framework-substituted Ti sites are the factors responsible for the superior activity of Ti-SBA-16 compared to Ti-SBA-12 and the hitherto known solid catalysts for this reaction. (C) 2012 Elsevier Inc. All rights reserved.</p>10aAminolysis of epoxides10abeta-Amino alcohol10aMesoporous titanosilicates10aMolecular sieves10aRing opening of epoxides with amines10aTi-SBA-1210aTi-SBA-161 aKumar, Anuj1 aSrinivas, Darbha  uhttps://library.ncl.res.in/content/aminolysis-epoxides-catalyzed-three-dimensional-mesoporous-titanosilicates-ti-sba-12-and-002000nas a2200241   4500008004100000022001400041245014400055210006900199260007300268300001000341490000800351520108600359653003401445653002501479653002101504653002401525653001401549653001401563653002001577100001601597700002101613856012401634       2012                        eng d  a0920-586100aSelective oxidation of cyclic olefins over framework Ti-substituted, three-dimensional, mesoporous Ti-SBA-12 and Ti-SBA-16 molecular sieves0 aSelective oxidation of cyclic olefins over framework Tisubstitut  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcDEC  a59-680 v1983 a<p>Framework Ti-substituted, three-dimensional, mesoporous titanosilicates, Ti-SBA-12 and Ti-SBA-16, were prepared by direct hydrothermal synthesis method. These catalysts showed catalytic activity higher than the hitherto known titanosilicates for the oxidation of cyclic olefins (cyclohexene and cyclooctene) with tert.-butyl hydroperoxide. An epoxide selectivity of 100% and olefin conversion greater than 92% were obtained. Cubic Ti-SBA-16 with interconnected cage-like mesopore structure was more active than hexagonal Ti-SBA-12. X-ray diffraction and diffuse reflectance UV-vis, Fourier transform infrared, Raman and electron paramagnetic resonance spectroscopies provided evidence for the substitution of Ti4+ (for Si4+) in the framework locations. The catalytic activity correlated with the concentration of framework-substituted, tetrahedral Ti4+ ions. Easy accessibility of the active sites and the three-dimensional mesoporous structure are the possible causes for the superior activity of these titanosilicate catalysts. (C) 2012 Elsevier B. V. All rights reserved.</p>10aEpoxidation of cyclic olefins10amesoporous materials10aMolecular sieves10aSelective oxidation10aTi-SBA-1210aTi-SBA-1610aTitanosilicates1 aKumar, Anuj1 aSrinivas, Darbha  uhttps://library.ncl.res.in/content/selective-oxidation-cyclic-olefins-over-framework-ti-substituted-three-dimensional-001819nas a2200229   4500008004100000022001400041245008800055210006900143260007300212300001200285490000800297520095700305653005101262653002101313653003901334653003701373653001401410653001401424100001601438700002101454856011401475       2013                        eng d  a1381-116900aHydroxylation of phenol with hydrogen peroxide catalyzed by Ti-SBA-12 and Ti-SBA-160 aHydroxylation of phenol with hydrogen peroxide catalyzed by TiSB  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAR  a112-1180 v3683 a<p>We report here, for the first time, the application of ordered, three-dimensional, mesoporous titanosilicates, Ti-SBA-12 and Ti-SBA-16, as reusable solid catalysts, for hydroxylation of phenol, an industrially important organic transformation. The reactions were conducted using 30% aqueous H2O2 as oxidant. The catalysts of this work are more efficient than the hitherto known mesoporous Ti-silicates. They are more para-product selective than TS-1 and other titanosilicates. Ti-SBA-12 exhibited higher activity and hydroquinone/catechol selectivity (by nearly two times) than Ti-SBA-16. H2O2 efficiency of similar to 90 mol% was obtained. Our study reveals that framework substituted Ti with pseudo-tetrahedral geometry, three-dimensional mesoporosity as well as surface structure are the unique features responsible for the high catalytic activity and selectivity of these titanosilicate catalysts. (C) 2012 Elsevier B.V. All rights reserved.</p>10aCatalytic liquid-phase hydroxylation of phenol10aMolecular sieves10aOrdered mesoporous titanosilicates10aOxidation with hydrogen peroxide10aTi-SBA-1210aTi-SBA-161 aKumar, Anuj1 aSrinivas, Darbha  uhttps://library.ncl.res.in/content/hydroxylation-phenol-hydrogen-peroxide-catalyzed-ti-sba-12-and-ti-sba-16-001769nas a2200253   4500008004100000022001400041245010500055210006900160260007300229300001000302490000800312520087000320653001401190653003301204653002501237653002501262653001401287653001401301653002001315100002301335700001601358700002101374856012001395       2013                        eng d  a1381-116900aThree-dimensional, mesoporous titanosilicates as catalysts for producing biodiesel and biolubricants0 aThreedimensional mesoporous titanosilicates as catalysts for pro  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcOCT  a65-730 v3773 a<p>The application of three-dimensional, mesoporous titanosilicates, Ti-SBA-12 and Ti-SBA-16, as reusable solid acid catalysts for producing biodiesel and biolubricants is reported for the first time. Biodiesel was prepared by esterification of oleic acid with monohydric methanol and biolubricants by esterification with polyhydric alcohols (glycerol, trimethylolpropane, neopentyl glycol and pentaerythritol). High catalytic activity of these catalysts is attributed to the presence of dispersed Lewis acidic Ti sites and mesoporosity in the structure. Biodiesel yields as high as 90 mol% were obtained at 443 K. Surface hydrophobicity of the catalyst has also a predominant role, especially, in reactions involving polyhydric alcohols. In those reactions, Ti-SBA-16 showed higher catalytic activity than Ti-SBA-12. (c) 2013 Elsevier B.V. All rights reserved.</p>10aBiodiesel10aEsterification of fatty acid10aLubricant basestocks10amesoporous materials10aTi-SBA-1210aTi-SBA-1610aTitanosilicates1 aKotwal, Mehejabeen1 aKumar, Anuj1 aDarbha, Srinivas  uhttps://library.ncl.res.in/content/three-dimensional-mesoporous-titanosilicates-catalysts-producing-biodiesel-and-0