Reação de cicloadição entre oxazóis e arinos visando à preparação de isoquinolinas funcionalizadas
Data
2019-03-21
Autores
Silva, Jéssica Kunsminskas da 
Orientadores
Raminelli, Cristiano
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
O núcleo isoquinolínico é encontrado em diversos produtos naturais bioativos e
fármacos utilizados no tratamento de várias enfermidades. Desta maneira, a
preparação de compostos isoquinolínicos tem sido investigada, por meio da reação
de cicloadição entre oxazóis e precursores de benzino, empregando condições
relativamente drásticas, envolvendo reagentes perigosos e temperaturas elevadas,
bem como reagente fortemente oxidante de chumbo (IV) em temperatura baixa.
Neste contexto, decidimos estudar a reação de cicloadição entre 4-ariloxazóis e
2-(trimetilsilil)aril triflatos, empregados como precursores de arinos, fazendo uso de
condições reacionais brandas, a qual resultou na formação de adutos de cicloadição
em rendimentos de 51% a 75%, que foram convertidos em 3-aril-4-
hidroxisoquinolinas, por reação com ácido trifluoroacético, em rendimentos de 75%
a 92%.
Isoquinoline core can be found in some bioactive natural products and synthetic drugs employed in the treatment of various diseases. Accordingly, the preparation of isoquinoline compounds have been explored through cycloaddition reactions between oxazoles and benzyne precursors, using relatively harsh reaction conditions, involving hazardous reagents and high temperatures, as well as Pb(OAc)4 as a strongly oxidizing reagent at low temperature. Therefore, we have decided to study the cycloaddition reaction between 4-aryloxazoles and 2- (trimethylsilyl)aryl triflates as aryne precursors, employing mild reaction conditions, leading to cycloadducts in 56-75% yields, which were converted to 3-aryl-4- hydroxyisoquinolines, through reaction with trifluoroacetic acid in 75-92% yields.
Isoquinoline core can be found in some bioactive natural products and synthetic drugs employed in the treatment of various diseases. Accordingly, the preparation of isoquinoline compounds have been explored through cycloaddition reactions between oxazoles and benzyne precursors, using relatively harsh reaction conditions, involving hazardous reagents and high temperatures, as well as Pb(OAc)4 as a strongly oxidizing reagent at low temperature. Therefore, we have decided to study the cycloaddition reaction between 4-aryloxazoles and 2- (trimethylsilyl)aryl triflates as aryne precursors, employing mild reaction conditions, leading to cycloadducts in 56-75% yields, which were converted to 3-aryl-4- hydroxyisoquinolines, through reaction with trifluoroacetic acid in 75-92% yields.