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Showing 1 to 20 of 180 for “"allylic"”.
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Catalytic, Enantioselective Cyclopropanation of Allylic Alcohols
In mechanistic investigations, spectroscopic examinations and reaction surveys of substrate, reagent, and promoter were combined with solid-state evidence concerning the active form of the catalytically operative species to rationalize many of the observed features and trends of this system. …
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Hydroamination of terminal allylic imines, allylic amines, and internal and terminal homoallylic amines: Regioselective and regiodivergent transformations
… anti-Markovnikov selective hydroamination of homoallylic amines to form 1,4-diamines with electron rich secondary cyclic and acyclic amine nucleophiles. This transformation is tolerant of a variety of substituents on the homoallylic amine and mechanistic studies on these substrates are summarized. …
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Asymmetric Transfer Hydrogenation of Secondary Allylic Alcohols
… method that transforms racemic secondary allylic alcohols into optically active secondary alcohols. The key step in this methodology occurs through a ruthenium catalyzed tandem isomerization and asymmetric transfer hydrogenation reaction. This reaction is a one pot, two-step process, which …
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Mechanistic studies on iridium catalyzed allylic substitution
Mechanistic studies on iridium catalyzed allylic substitution reactions catalyzed by iridium phosphoramidite complexes revealed that the active catalyst is generated through a base assisted cyclometalation of the phosphoramidite to form five-membered iridacycle. A mechanism for the reaction was …
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Free radical reactions of allylic and propargylic derivatives
<p>Addition of tert-butyl radical, generated from t-BuHgCl, to allyl or propargyl derivatives forms adduct radicals which can undergo [beta]-elimination with substituents such as halogen, PhS, PhSO[subscript]2 to form the alkyl-substituted propene or allene and an eliminated radical which …
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Palladium(II) catalyzed allylic C-H alkylation reactions
… discovery of the first palladium(II)-catalyzed allylic C-H alkylation reaction. Allylic alkylation has long been performed by palladium(0) catalysis with allylic oxygenate starting materials. In contrast, this method proceeds directly from the readily accessible, chemically robust a-olefin …
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Linear allylic C-H oxidation: methods and utility
… group tolerance, and streamlining utility of our allylic C-H oxidation chemistry. In general, functional groups are installed in complex molecules through the advent of sequential C-C bond forming reactions. This chemistry is not only well known, but has been employed for decades, resulting in the …
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Asymmetric Syntheses With (-)-Sparteine-Complexed Benzylic and Allylic Organolithium Reagents
The kinetic resolution of racemic cyclic unsaturated esters with the organolithium intermediates derived from lithiation of N-Boc- N-(p-methoxyphenyl)cinnamylamine with n -BuLi/(-)-sparteine was investigated. Kinetic resolution in conjugate addition reactions with alpha,beta-unsaturated lactones …
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Dechalcogenative Allylic Selenosulfide And Disulfide Rearrangements For Cysteine Modification And Glycoligation
… is placed on the newly invented silver mediated allylic desulfurative rearrangement for the primary modification of thiols and the synthesis of complex oligosaccharide mimics.</p> <p>Chapter one introduces the concept of chemoselective ligations for the modification of macromolecules like …
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New frontiers in allylic C––H amination via palladium/sulfoxideoxazoline catalysis
Direct allylic C––H functionalization of terminal olefin represents an orthogonal approach to traditional methods to build C––O, C––N and C—C bond due to less oxidation state manipulation and synthetic overhead. In particular, site, chemo- and stereoselective methods for Pd(II)-catalyzed allylic …
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Allylic C—H activation to access anti-1,3-amino alcohol motifs
1,3-Amino alcohols are common motifs in a variety of biologically active molecules including antivirals, antibiotics, antifungals, and various alkaloids. Due to their prevalence and utility as synthetic intermediates, a variety of methods have been developed to access these motifs in a …
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Asymmetric allylic C–H functionalization via palladium(II)/sulfoxide-oxazoline catalysis
… this context, palladium(II)-catalyzed asymmetric allylic C–H functionalization of terminal olefins through the intermediacy of π-allyl/Pd(II) complex represents a viable platform. Traditionally, the asymmetric functionalization of π-allyl/Pd(II) intermediate generally proceeded with …
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The development of Pd(II)sulfoxide-oxazoline catalyzed allylic C—H functionalizations
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2023-12-01
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Asymmetric Lithiation-Substitution Sequences of Functionalized Allylic and Benzylic Amines Mediated by (-)-Sparteine
Modification of the allyl amine with selected substituents at the beta and gamma-positions allowed for an examination of yields, product distributions, enantioenrichments, mechanistic understanding and synthetic applications. With an extended allyl amine, enantioenriched diene products were …
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Expanding the scope of allylic C—H aminations via electrophilic palladium(II) catalysis
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2026-08-01
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Palladium (II) / sulfoxide - promoted strategies for efficient and selective allylic C-H oxidations
… broad applicability toward a wide array of allylic C–H functionalizations, starting from abundant and simple α-olefins. The development of such transformations has been classically guided by the reaction’s serial ligand catalysis mechanism, requiring weakly-binding ligands for the palladium …
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Synthesis and synthetic transformations of allylic alcohols, epoxy alcohols, and 1,2-cyclic sulfates
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1988.
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