Calix[n]arene-catalyzed three-component povarov reaction: microwave-assisted synthesis of Julolidines and mechanistic insights

• Autor(a) principal: Abranches, Paula Aline da Silva
• Data de Publicação: 2018
• Outros Autores: Paiva, Walysson Ferreira de, Fátima, Angelo de, Martins, Felipe Terra, Fernandes, Sergio Antonio
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: https://doi.org/10.1021/acs.joc.7b02532; http://www.locus.ufv.br/handle/123456789/18235
• topic: Povarov reaction; Calix[n]arene-catalyzed

A new one-pot cascade reaction-based application of Povarov reactions with a p-sulfonic acid calix[4]arene catalyst for the synthesis of a series of 34 julolidine derivatives with substituents at C8 or C9 in good to excellent yields is reported. These microwave-assisted reactions proceeded efficiently, had short reaction times, were metal-free, were low cost, and used an inexpensive, easily available and nontoxic catalyst. These advantages, along with a simple workup procedure, make this protocol a very efficient and green alternative to the traditional methods for constructing these types of N- heterocyclic skeletons. In addition, this protocol allows the formation of julolidine structures, which requires the construction of four new C−C bonds and two C−N bonds. A mechanism for the Povarov reaction involving a stepwise sequence via ionic intermediates was proposed and validated.