Catalytic Asymmetric Synthesis
Mostrando 1-12 de 16 artigos, teses e dissertações.
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1. A New Energetic Complex: Synthesis, Structure, and Combustion Catalysis Performance
The potential of tetrazole-based ligands for forming energetic complexes applied in pyrotechnics and propellants is demonstrated with the use of 5,5’-(1,3-phenylene)bis(1H-tetrazole) (H2BTB) to generate an energetic complex with high energy. A new energetic complex of PbII-tetrazolate, [Pb2(BTB)2(H2O)8]·5H2O (1), was synthesized and structurally character
J. Braz. Chem. Soc.. Publicado em: 2020-08
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2. Sintese e atividade biologica de analogos furanicos da goniotalamina / Synthesis and biological activity of furan analogues of goniothalamin
This work describes the preparation of furan analogues of goniothalamin (compounds 31, 32 and 33) in both enantiomeric forms through the utilization of Keck asymmetric allylation and ring-closing methatesis reaction. These analogues were prepared in good overall yield and excellent enantiomeric ratio. These novel compounds were evaluated as antiproliferative
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 07/07/2009
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3. Alilação e crotilação catalítica e enantiosseletiva de aldeídos
The field of chiral catalysis has experienced explosive growth over the last two decades. By now, many of the classical reactions in organic synthesis can be carried out efficiently in asymmetric manner. As one of the fundamental and powerful C-C bond-forming reactions, enantioselective catalytic allylation (ECA) and crotylation (ECC) of aldehydes has attrac
Química Nova. Publicado em: 2006-10
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4. Reações aldólicas assimétricas catalíticas
This review describes the use of catalytic asymmetric aldol reactions of silyl enol ethers and silyl (thio)ketene acetals with aldehydes (the Mukaiyama aldol reaction) in order to illustrate its synthetic utility. A variety of Lewis acid and basic reagents were employed for catalytic aldol reactions with high diastereo- and enantioselectivities. The origins
Química Nova. Publicado em: 2003-08
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5. Catalytic asymmetric synthesis of all-carbon quaternary stereocenters
Only a few catalytic asymmetric C—C bond-forming reactions have been shown to be useful for constructing all-carbon quaternary stereocenters. This Perspective examines the current state of such methods.
National Academy of Sciences.
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6. Catalytic asymmetric reactions for organic synthesis: The combined C—H activation/Cope rearrangement
The development of new catalytic asymmetric reactions can lead to exciting new strategies for organic synthesis. This article describes the synthetic utility of the combined C—H activation/Cope rearrangement, achieved by dirhodium tetraprolinate-catalyzed reaction of vinyldiazoacetates with compounds containing allylic C—H bonds. The transformation is hi
National Academy of Sciences.
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7. Mo-catalyzed asymmetric olefin metathesis in target-oriented synthesis: Enantioselective synthesis of (+)-africanol
Catalytic asymmetric ring-opening metathesis (AROM) provides an efficient method for the synthesis of a variety of optically enriched small organic molecules that cannot be easily prepared by alternative methods. The development of Mo-catalyzed AROM transformations that occur in tandem with ring-closing metathesis are described. The utility of the Mo-catalyz
National Academy of Sciences.
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8. Stereoselective terminal functionalization of small peptides for catalytic asymmetric synthesis of unnatural peptides
The asymmetric phase-transfer catalytic alkylation of peptides has been achieved by the use of designed C2-symmetric chiral quaternary ammonium bromide 1 as catalyst. Excellent stereoselectivities were uniformly observed in the alkylation with a variety of alkyl halides and the efficiency of the transmission of stereochemical information was not affected by
National Academy of Sciences.
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9. Effect of sulfide structure on enantioselectivity in catalytic asymmetric epoxidation of aldehydes: Mechanistic insights and implications
Bridged bicyclic sulfide 1 was originally found to provide high levels of asymmetric induction in sulfur ylide-mediated epoxidations. This sulfide possesses chirality in the [2.2.1] thioether moiety and the [2.2.1] camphor-derived carbocyclic moiety. To determine whether the optimal sulfide had been used, a diastereomer of sulfide 1 in which the stereochemis
National Academy of Sciences.
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10. Solid-phase synthesis of chiral 3,4-diazaphospholanes and their application to catalytic asymmetric allylic alkylation
Functionalized chiral diazaphospholanes ligate to a variety of transition metals, yielding chiral, catalytically active, metal complexes. Previous work has established that amino acid derivatization of the carboxyl groups of (R,R)-N,N′-phthaloyl-2,3-(2-carboxyphenyl)-phenyl-3,4-diazaphospholane (1) yields phosphines that are excellent ligands for palladium
National Academy of Sciences.
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11. Catalytic enantioselective intermolecular cycloadditions of 2-diazo-3,6-diketoester-derived carbonyl ylides with alkene dipolarophiles
Catalyzed cascade reactions that generate molecular complexity rapidly and in an enantioselective manner are attractive methods for asymmetric synthesis. In the present article, chiral rhodium catalysts are shown to effect such a transformation by using a range of 2-diazo-3,6-diketoesters with bicyclo[2.2.1]alkenes and styrenes as reaction partners. The reac
National Academy of Sciences.
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12. Catalytic asymmetric addition of diorganozinc reagents to N-phosphinoylalkylimines
The synthesis of α-chiral amines bearing two alkyl groups has been hampered by the accessibility and stability of the alkylimine precursor. Herein, we report an efficient strategy to generate the alkyl-substituted imine in situ that is compatible with the Me-DuPHOS monoxide·Cu(I) catalyzed addition of diorganozinc reagents. The sulfinic acid adduct of the
National Academy of Sciences.