Use este identificador para citar o ir al link de este elemento: http://hdl.handle.net/1843/SFSA-BALQHY
Tipo: Dissertação de Mestrado
Título: Green solvents for the hydroaminomethylation of estragole 
Autor(es): Maria Gabriela Paredes Gutierrez
primer Tutor: Eduardo Nicolau dos Santos
primer miembro del tribunal : Eduardo Eliezer Alberto
Segundo miembro del tribunal: Guilherme Ferreira de Lima
Resumen: Aborda a utilização de solventes verdes para a hidroaminometilação de propenilbenzenos de origem natural (estragol).
Abstract: Hydroaminomethylation (HAM) is a simple route to synthesize amines through a highly atom-economic reaction of alkene with syngas (carbon monoxide/hydrogen mixture) and a primary or secondary amine. HAM consists of three successive steps occurring in the same reactor: hydroformylation, condensation of the aldehyde with the amine, and hydrogenation. Both hydroformylation and hydrogenation are catalyzed by transition metal complexes. In this work, a series of novel amines withpotential bioactivity was obtained in excellent yields. Some eco-friendly solvents were employed for the first time in this reaction. p-Cymene, anisole and ethanol proved to be excellent greener alternatives for toluene, the solvent conventionally used for hydroaminomethylation. The performance of p-Cymene and anisole was similar to that of toluene; whereas the reactions in ethanol solutions showed better yields and selectivity for the products. Propyl anisole was also tested, but the resultswere not as good as the others solvents, as significant amounts of enamines were not hydrogenated. The regioselectivity varied with the amine counterpart: the / ratio was 40/60 in the reactions with di-n-butylamine vs. 50/50 in those with 4-methylpiperidine. Thus, thenature of the amine counterpart seems to affect the reactivity of rhodium species operating in the hydroformylation step of the HAM process. The reactions with morpholine gave excellent yields of main products, with their isomeric composition being dependent on the solvent nature. In toluene, p-Cymene, anisole and propyl anisole, the substrate isomerization and the hydroformylation of the resulting anethole were significant. In ethanol, the isomerization of estragole was much lesssignificant. HAM of estragole with 2,6-dimethylmorpholine, gave excellent yields in all solvents, except propyl anisole where the last step (hydrogenation) was not favourable, and enamine intermediate remained in significant amounts.
Asunto: Solventes
Álcool
Recursos naturais renováveis
Catálise
Hidrogenação
Química inorgânica
Produtos naturais
Aminas
Idioma: Português
Editor: Universidade Federal de Minas Gerais
Sigla da Institución: UFMG
Tipo de acceso: Acesso Aberto
URI: http://hdl.handle.net/1843/SFSA-BALQHY
Fecha del documento: 25-feb-2019
Aparece en las colecciones:Dissertações de Mestrado

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