01953nas a2200241 4500008004100000022001400041245012100055210006900176260007300245300001000318490000800328520104500336653002201381653001801403653003301421653002201454653002701476100001701503700001901520700001701539700002801556856012701584 2009 eng d a0926-860X00aOxidative kinetic resolution of alcohols using chiral Mn-salen complex immobilized onto ionic liquid modified silica0 aOxidative kinetic resolution of alcohols using chiral Mnsalen co aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcFEB a17-250 v3543 a

The supported ionic liquid strategy has been applied for the immobilization of chiral Mn(III) salen complex onto ionic liquid modified silica. Chiral Mn(III) salen complex was immobilized over silica through a thin film of covalently anchored imidazolium ionic liquid. These catalysts were characterized by N(2) sorption, XRD, MR, DRUV-vis, and elemental analysis. The results showed that the chiral Mn(III) salen complex could be successfully immobilized onto the modified mesoporous materials and that the long-range mesoporous ordering of parent supports was maintained after the immobilization. The immobilized catalyst provided good enantioselectivity and activity in the heterogeneous catalysis of the oxidative kinetic resolution of secondary alcohol and can be recovered and recycled for four times without obvious loss of enantioselectivity and activity. Oxidative kinetic resolutions of meso-diols, hydroxyl ester and primary alcohol were also studied using this catalyst system. (C) 2008 Elsevier B.V. All rights reserved.

10aMesoporous silica10aMn(III) salen10aOxidative kinetic resolution10aSecondary alcohol10aSupported ionic liquid1 aSahoo, Suman1 aKumar, Pradeep1 aLefebvre, F.1 aHalligudi, Shivaraj, B. uhttps://library.ncl.res.in/content/oxidative-kinetic-resolution-alcohols-using-chiral-mn-salen-complex-immobilized-ionic-001662nas a2200265 4500008004100000022001400041245015200055210006900207260009500276300001200371490000800383520066000391653002301051653002201074653002201096653001301118653001501131653002701146653001301173100001701186700001901203700001701222700002801239856012901267 2009 eng d a0021-951700aSynthesis of chiral sulfoxides by enantioselective sulfide oxidation and subsequent oxidative kinetic resolution using immobilized Ti-binol complex0 aSynthesis of chiral sulfoxides by enantioselective sulfide oxida a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcFEB a111-1180 v2623 a

Chiral Ti-binol complex was immobilized onto ionic liquid modified SBA-15 and characterized by different physicochemical techniques. The catalyst was found to be highly enantioselective in the heterogeneous asymmetric oxidation of prochiral sulfides to sulfoxides and subsequent oxidative kinetic resolution of the sulfoxides using aqueous tert-butylhydroperoxide as the oxidant. A positive non-linear effect was observed in the oxidation-kinetic resolution of thioanisole using this supported catalyst. The supported catalyst was reused in multiple catalytic runs without any loss of enantioselectivity. (C) 2008 Elsevier Inc. All rights reserved.

10aKinetic resolution10aMesoporous silica10aNon-linear effect10aSulfides10aSulfoxides10aSupported ionic liquid10aTi-binol1 aSahoo, Suman1 aKumar, Pradeep1 aLefebvre, F.1 aHalligudi, Shivaraj, B. uhttps://library.ncl.res.in/content/synthesis-chiral-sulfoxides-enantioselective-sulfide-oxidation-and-subsequent-oxidative-002363nas a2200229 4500008004100000022001400041245008400055210006900139260007500208300001200283490000700295520151500302653003501817653003101852653001901883653002201902653003301924100001701957700002001974700002801994856011102022 2011 eng d a1571-101300aOrdered mesoporous silica as supports in the heterogeneous asymmetric catalysis0 aOrdered mesoporous silica as supports in the heterogeneous asymm a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGER/PLENUM PUBLISHERScSEP a200-2140 v153 a

Enantioselective synthesis of organic compounds has been studied by homogeneous catalysts for several years. However, these catalysts have yet to make a significant impact on industrial scales for fine chemical synthesis. A primary reason is the designing of a homogeneous asymmetric catalyst, which requires relatively bulky ligands and catalyst recovery and recycling often causes problems. One of the convincing ways to overcome this problem is to immobilise the asymmetric catalyst onto a solid support and the resulting heterogeneous asymmetric catalyst system can, in principle, be readily re-used. A large number of supports such as inorganic oxides including zeolites, alumina, zirconia, silica and organic polymers have been employed as supports in heterogeneous asymmetric catalysis. Therefore, in this review article we have summarized the work done by us in our laboratory on the immobilization of chiral transition metal complexes such as Ru, Ir, Mn and Ti onto ordered mesoporous silica and its asymmetric catalysis. All these immobilized catalysts were well characterized by different physicochemical techniques to confirm the structural retention of the support as well as the active metal complex after immobilization. This report includes our asymmetric catalytic investigations in enantioselective reactions such as hydrogenation of ketones, olefins, oxidation of sulfides and oxidative kinetic resolution of alcohols and sulfoxides through immobilized heterogeneous catalyst systems.

10aEnantioselective hydrogenation10aEnantioselective oxidation10aImmobilization10aMesoporous silica10aOxidative kinetic resolution1 aSahoo, Suman1 aBordoloi, Ankur1 aHalligudi, Shivaraj, B. uhttps://library.ncl.res.in/content/ordered-mesoporous-silica-supports-heterogeneous-asymmetric-catalysis-0