Synthesis of trivalent phosphorus compounds for the Diels-Alder reaction.
Item
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Title
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Synthesis of trivalent phosphorus compounds for the Diels-Alder reaction.
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Identifier
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AAI9917714
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identifier
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9917714
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Creator
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Xu, Ping.
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Contributor
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Adviser: William H. Hersh
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Date
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1999
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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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Chemistry, Organic | Chemistry, Inorganic
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Abstract
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Reaction of chelating phosphine But2PCH 2CH2PPh2, diphos, diphos-F20, or diTosL with trans-BrW(CO)4(NO) gave cis,cis,trans-(chelate)(CO) 2(NO)WBr as the catalyst precursor, which further reacted with AgSbF 6 to form the reactive Lewis acidic tungsten cations as the SbF 6- adduct.;Both catalytic and stoichiometric results showed that racemic catalyst C7 was comparable to catalyst C1 regarding the reactivity. This remarkable result excluded the possibility that simple steric bulk caused the extremely low reactivity of catalyst C5 containing a C 2 symmetric ligand, and suggested a new direction for the design of ligands. Ferrocene derived chiral catalysts Crs8-1 and Crs8-2 confirmed the high catalytic reactivity of ligands having Bu t2RP/PRPh2 moieties.;Reaction of N,N'-bis(tolysulfonyl)-1,2-diaminoethane with PhPCl2 gave a 62% yield of TosL; while with Ph2PCl, a 43% yield of diTosL was achieved. Reaction of (S)-N-tolylsulfonylvaline with PhPCl2 gave a nearly quantitative yield of a novel 1,3,2-oxazaphospholidin-5-one (14a and 14b) as a greater than 7:1 mixture of diastereomers.;The IR data are interpreted to suggest a relative order of ligand acceptor ability as P(CF3)3 > TosL ≈ P(OMe) 3 > PPh3≈ PP(NEt2)2 and a relative order of a ligand donor ability as PP(NEt2)2 ≥ P(OMe) 3 > PPh3 > TosL > P(CF3) 3. The IR data also suggests that 14a is a strongly electron-deficient ligand, which is only less deficient than P(CF3)3, and the chelating ligand diTosL is about as electron-deficient as diphos-F20.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
