Desenvolvimento de metodologias sintéticas utilizando química em fluxo contínuo na redução de Meerwein-Ponndorf-Verley e síntese de pirazolinas

Author(s)

Henrique Magri Marçon

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Química
• Defense date: 2021-08-05

Examining board members

Júlio Cezar Pastre; Ronaldo Aloise Pilli; Kleber Thiago de Oliveira

• Advisor: Júlio Cezar Pastre

Abstract

Continuous-Flow Microreactors and Green Chemistry are areas of science with promising applications, especially when allied. In this scenario, the main idea of this project was to develop new strategies for the synthesis of bio-based compounds under flow regime. Initially, we have turned our attention towards the flow synthesis of HMF and its derivative DHMF (di-(hydroxymethyl)furan). We have used furfural reduction to furfuryl alcohol as a model substrate for HMF reduction using a Meerwein-Ponndorf-Verley reaction with iso-propanol as hydride source catalysed by zirconium (IV) materials. We have prepared Furfuryl alcohol in 95% yield with a productivity of 35 mg min-1. Efforts towards HMF reduction were performed and the process was optimized using Design of Experiments. The optimal condition was determined for 0.25 mol L-1 of HMF and was determined to be 120 °C and 50 s of residence time, giving yields of 70% and a productivity of 50 mg min-1. We have also used a continuous flow platform for the synthesis of 2-pyrazolines in a controlled fashion, avoiding chemical exposure to reactive intermediates. A library of 20 compounds was prepared using electron-poor alkenes and reactive diazo intermediates generated from their respective hydrazones with yields between 30-89% (AU)

• FAPESP's process: 18/25233-1 - Continuous flow synthesis of biomass-derivatives
• Grantee: Henrique Magri Marçon
• Support Opportunities: Scholarships in Brazil - Master