Development of highly efficient transition metal-catalyzed addition reactions
Item
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Title
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Development of highly efficient transition metal-catalyzed addition reactions
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Identifier
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d_2009_2013:90c254cd1c70:11065
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identifier
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11391
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Creator
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Liao, Yuanxi,
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Contributor
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Qiaosheng Hu
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Date
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2011
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Language
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English
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Publisher
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City University of New York.
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Subject
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Organic chemistry | Physical chemistry
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Abstract
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Development of new and efficient reactions as powerful tools for synthetic chemistry is one of the most important tasks in modern chemistry. Transition metal-catalyzed carbon-carbon bond-forming reactions including addition reactions are some of the most powerful transformations in organic synthesis. My research is on developing highly efficient transition metal-catalyzed addition reactions as powerful tools for organic synthesis.;There are two parts of my Ph. D. dissertation research projects. In the first part, based on our understanding on transmetalation and reductive elimination of palladium catalysis, we minimized the decomposition of catalysts and developed a series of new, highly efficient Pt(II), Pd(II), Rh(I) and Cu(II)-catalyzed addition reactions of organoboron reagents with carbonyl-containing compounds. Since Pt complexes can undergo reductive elimination very reluctantly, we explored the platinacycle-catalyzed addition reaction of arylboronic acids with aldehydes with low catalyst loadings. However, the low catalyst loading catalysis with platinacycles as catalysts was achieved at the expense of the catalyst catalytic activity. In order to minimize the decomposition of catalyst as well as keep the catalytic activity, a new anhydrous condition of addition reactions was established and a novel non-transmetalation mechanism of the Pd-catalyzed addition reaction was proposed and demonstrated. Under the guidance of the new reaction mechanism, we pinpointed that some addition reactions which are thought to be hardly achievable before may be accomplished now. By using the anhydrous condition, we explored Cu-catalyzed addition reactions of arylboroxines with carbonyl-containing compounds and Rh-catalyzed addition reactions of arylboroxines with ketones.;In the second part, to make the addition reactions we developed in the first part be more powerful, we explored new tandem/sequential reactions involved such addition reactions as one of bond-forming reactions. Specifically, we combined Pt(II)-catalyzed 1,2-addition reactions of arylboronic acids and aldehydes with the secondary alcohol oxidation process in a tandem fashion to synthesis aryl ketones from readily available aldehydes and arylboronic acids. We also developed the synthesis of beta-arylated ketones via the aldol condensation of aldehydes with methyl ketones followed by transition metal-catalyzed addition reaction in a sequential and tandem fashion. Such sequential/tandem protocols offer us rapid entry to synthesize complex materials or biological active compounds from simple precursors.
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Type
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dissertation
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Source
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2009_2013.csv
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degree
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Ph.D.
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Program
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Chemistry
