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A. Advances in Copper Hydride-Catalyzed Reactions B. Bimetallic Heterogeneous Catalysis C. Tandem Olefin Metathesis/Elimination

Posted on:2012-12-12Degree:Ph.DType:Thesis
University:University of California, Santa BarbaraCandidate:Boskovic, Zarko VFull Text:PDF
GTID:2461390011461427Subject:Chemistry
Abstract/Summary:
Catalytic amounts of copper hydride ligated with a variety of ligands have been shown to effectively enable numerous reactions, most famously conjugate reductions of alpha,beta-unsaturated carbonyl compounds. This dissertation describes furthering the application of ligated CuH. Specifically: I) a bis-phosphine analogue of Stryker's reagent has been shown to be a more active reagent for Michael type hydrosilylations; II) hydroboration of ynoates has been achieved using catalytic amounts of phosphine ligated CuH using pinacolborane. Reactivity of these novel alpha-boryl enoates has been assessed; III) approaches to enantioselective reductive Ireland-Claisen rearrangement of allylic enoates are described; IV) substrate controlled shift in regioselectivity of CuH-catalyzed hydrosilylations of alpha,beta-unsaturated ketones from 1,4- to 1,2-mode has been discovered. This reactivity allowed for valuable nonracemic allylic alcohols to be synthesized in high yields and with enantioselectivities up to 96%.;Solid-supported catalysts are highly desirable in pharmaceutical industry as they allow for easy separation of catalyst from the reaction mixture. Although most commonly limited to one active metal species impregnated on a solid support, multiple metals offer some inherent advantages to the catalysis. Copper-and-nickel on charcoal is described herein as such a bimetallic catalyst, capable of effecting transformations characteristic of each separate metal (etherifications and conjugate reductions presented in detail) as well as consecutive reactions for which both metals are necessary.;Development of tandem processes in organic synthesis is a highly desirable goal. Ruthenium catalyzed olefin metathesis coupled with E2 elimination is described herein as a method for obtaining alpha,beta,gamma,delta-dienyl carbonyl compounds.
Keywords/Search Tags:Reactions
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