Metathesis
Mostrando 1-12 de 43 artigos, teses e dissertações.
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1. OBSERVAÇÃO DE HOMODÍMERO DO TIPO BIS-1,3-BENZODIOXONA SINTETIZADO VIA METÁTESE DE OLEFINAS DA PIPERINA CATALISADA POR PRÉ-CATALISADORES DE RU(II) NÃO COMERCIAIS
LN-1 and LN-2 are two Ru(II) complexes coordinated to the phosphine and amines simultaneously, each with two chlorides. PPh3 is the phosphine and the amine is piperidine (LN-1) and perhydroazepine (LN-2). The two compounds are complexes five-coordinated square pyramidal geometry, with the amine in the axial plane. LN-1 and LN-2 were tested for the first time
Química Nova. Publicado em: 2022
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2. INFLUÊNCIA DO IMPEDIMENTO ESTÉRICO DE LIGANTES ANCILARES EM COMPLEXOS A BASE DE Ru APLICADOS EM METÁTESES DO ÁLCOOL E ACETATO CINAMÍLICOS
Cinnamyl alcohol (AC) and cinnamyl acetate (ACM) were used as substrates in olefin metathesis reactions catalyzed by RuCl2(PCy3)2(=CHPh), first-generation Grubbs catalyst-G1, and RuCl2(PCy3)(H2IMes)(= CHPh), second-generation Grubbs catalyst-G2. The reactions occurred in the same reaction conditions for both substrates, 50 °C, for 24 h, in the proportions R
Quím. Nova. Publicado em: 2020-01
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3. Preparation and Characterization of Clay-polymer Nanocomposite Having Covalently-bound poly(norbornenes) with Pendant Cholesterols
We have successfully prepared a clay-based polymer nanocomposite having grown cholesterol bearing poly(norbornene) brushes end-tethered from a naturally-occurring montmorillonite clay template. The synthesis of this hybrid material involved the treatment of the clay with first generation Grubbs catalyst, a ruthenium alkylidene, which induced a ring-opening m
Mat. Res.. Publicado em: 10/01/2019
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4. Chain Elongation Influence in Copolymerization with Different Diesters of Norbornene 2,3-Dicarboxylic Acid Monomers via ROMP under Air Atmosphere
Diesters of norbornene 2,3-dicarboxylic acid (NBE-(COOR)2), in which R is an alkyl group, were synthesized from one-pot synthesis method with 5-norbornene-2,3-dicarboxylic acid and methanol and ethanol. The new monomers were, respectively, the dimethyl ester NBE-(COOCH3)2 and diethyl ester NBE-(COOCH2CH3)2. Norbornene was mixed with these monomers at differe
J. Braz. Chem. Soc.. Publicado em: 2018-06
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5. Functionalization of P3HT with Various Mono- and Multidentate Anchor Groups
Due to its favorable optoelectronic properties and the accessibility via Grignard metathesis (GRIM) polymerization, poly(3-hexylthiophene) (P3HT) is one of the most applied conjugated polymers. The ‘living' nature of GRIM polymerization enables the modification of the polymer and the installation of desired properties. In the present study, two versatile a
J. Braz. Chem. Soc.. Publicado em: 2018-05
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6. Synthesis of Chiral 1,3-Dienes through Ring-Closing Metathesis of Enantioenriched Enynes: Potential Precursors of Morphane Analogs
ABSTRACT A simple methodology for the synthesis of enynes by indium mediated diastereoselective allylation of aromatic N-tert-butanesulfinylimines bearing alkenyl groups at ortho-position with allyl bromide has been developed. The addition of the allyl indium intermediate to the chiral imine took place with excellent diastereoselectivity. Ruthenium-catalyzed
An. Acad. Bras. Ciênc.. Publicado em: 2018
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7. Deacylative alkylation (DaA) of N-methyl-3-acetyl-2-oxindole for the synthesis of symmetrically 3,3-disubstituted 2-oxindoles. An access gate to anticancer agents and natural products.
ABSTRACT The synthesis of 3,3-disubstituted N-methyloxindoles, starting from 3-acetyl-2-hydroxy-1-methyloxindole employing a sequential one-pot synthesis, is studied. The process involves a first alkylation in the presence of 1 equiv. of both organic halide and Triton B and the second one employs another 1.5 equiv. of each in moderate to high yields. This pr
An. Acad. Bras. Ciênc.. Publicado em: 2018
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8. Atom Transfer Radical Polymerization of Methyl Methacrylate Mediated by Grubbs 1st and 2nd Generation Catalysts: Insight into the Active Species
Ruthenium benzylidene complexes were evaluated as catalysts in atom-transfer radical polymerization (ATRP) of methyl methacrylate (MMA) under different reaction conditions. The mechanism by which Grubbs 1st and 2nd generation catalysts mediate olefin metathesis has been studied, little is known regarding the mechanism of ATRP reaction promoted by these compl
J. Braz. Chem. Soc.. Publicado em: 2017-08
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9. Unsaturated Renewable Oil Transformation into Novel Biofuel Compositions via an Olefin Metathesis-Transesterification-Hydrogenation Sequence
O uso sequencial de reações de etenólise, transesterificação e hidrogenação de um óleo renovável modelo para a preparação de potenciais biocombustíveis é reportado. Conversões de até 70% foram obtidas na etenólise de óleo de oliva usando uma pressão relativamente baixa de etileno (2 bar) e tolueno como solvente. O óleo de oliva etenolisado
J. Braz. Chem. Soc.. Publicado em: 2014-12
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10. Coordenação a centros de rutênio e polimerização via metátese de um novo monômero-ligante do tipo norborneno-piridina / Coordination to ruthenium centers and polymerization via metathesis of a new monomer-ligand of type norbornene-pyridine
O monômero-ligante (3amdpy)2NBE foi sintetizado e caracterizado por análise elementar (CHN), infravermelho e RMN (1H e 13C), tratando-se de um novo ligante quelante que apresenta duas piridinas conectadas ao monômero norborneno via grupos amidas. Esse monômero-ligante foi ligado a um centro de Ru(II)-polipiridínico e o complexo resultante foi caracteriz
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 09/03/2012
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11. Aminas acíclicas como ligantes ancilares em catalisadores de rutênio para polimerização via metátese de olefinas cíclicas / Acyclic amines as ancillary ligands in ruthenium catalysts for ring opening metathesis polymerization
As moléculas à base de nitrogênio, NH2Ph, NH2CH2Ph e NHnBuPh foram investigadas como ligantes ancilares nos novos complexos do tipo [RuCl2 (PPh3)2 (amina) x] para a polimerização via metátese por abertura de anel (ROMP) de norborneno (NBE), norbornadieno (NBD) e diciclopentadieno (DCPD). Os complexos foram obtidos da síntese com [RuCl2 (PPh3)3] com as
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 17/02/2012
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12. ROMP como um método versátil para a obtenção de materiais poliméricos diferenciados
Ring Opening Metathesis Polymerization (ROMP) of cyclic olefins is a powerful transition metal-catalyzed reaction for syntheses of polymers and copolymers. The key feature of this reaction is the [2+2]-cycloaddition mechanism, with retention of the olefinic unsaturation in the polymer chain and occurrence of living polymerization. With the development of met
Química Nova. Publicado em: 2012