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dc.contributor.advisorSamuelson, A G
dc.contributor.authorSharma, Rakesh Kumar
dc.date.accessioned2010-07-21T09:21:19Z
dc.date.accessioned2018-07-30T15:01:51Z
dc.date.available2010-07-21T09:21:19Z
dc.date.available2018-07-30T15:01:51Z
dc.date.issued2010-07-21
dc.date.submitted2008
dc.identifier.urihttps://etd.iisc.ac.in/handle/2005/778
dc.description.abstractChiral bisphosphinites are well-documented alternatives for chiral bisphosphines as ligands that can be exploited in various asymmpetric syntheses. Particularly, vicinal biarylphophinite ligands give a seven membered chelate ring similar to the successful DIOP on coordination to the metal. RajanBabu and coworkers have described asymmetric bisphosphinites obtained by functionalization of sugars and have shown their utility in enantioselective hydrogenation, hydrovinylation and hydrocynation reactions. Despite the interesting reactions demonstrated by bisphosphinites, not much attention has been paid to their synthesis and catalysis. This is probably due to the known moisture and oxygen sensitivity that makes their use limited. In the present thesis, a series of C1 an C2 symmetric bisphosphinite complexes of Pd(II) and Pt(II) have been synthesized directly from various naturally occurring chiral alcohols using a modified template method. A number of asymmetric catalytic reactions have been developed such as allylation of imines, allylation of aldehydes, allylic allylation, allylic alkylation, hydrosilylation of alkenes and regioselective allylation of oxiranes. Allylation of imines was carried out in essentially neutral conditions using Pd(II) catalysts and water was shown to accelerate the reaction. Interestingly acetic acid was required as a promoter in asymmetric allylation of cinnamaldehyde in the Pt(II) catalyzed reaction whereas water was a deterrent. Hydrosilylation reaction was carried out in solvent free conditions with high turnover numbers (.1000). Ascorbic acid based complexes produced the highest enantioselectivity for the asymmetric allylic alkylation reaction (97 % ee) and hydrosilylation of styrene (98% ee). These enantioselectivity results are the best obtained using ligands directly prepared from natural products.en_US
dc.language.isoen_USen_US
dc.relation.ispartofseriesG22323en_US
dc.subjectCatalysisen_US
dc.subjectChiral Bisphosphinitesen_US
dc.subjectChiral Catalystsen_US
dc.subjectImines - Allylationen_US
dc.subjectAldehydes - Allylationen_US
dc.subjectStyrene - Hydrosilylationen_US
dc.subjectAsymmetric Allylic Alkylationen_US
dc.subjectBisphosphinite Complexes - Synthesisen_US
dc.subjectAsymmetric Hydrosilylationen_US
dc.subjectAsymmetric Catalysisen_US
dc.subject.classificationPhysical Chemistryen_US
dc.titleChiral Bisphosphinites For Asymmetric Catalysisen_US
dc.typeThesisen_US
dc.degree.namePhDen_US
dc.degree.levelDoctoralen_US
dc.degree.disciplineFaculty of Scienceen_US


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