abstract
The synthesis of 4,6-disubstituted isoindoline-1,3-diones through microwave-assisted Diels-Alder (DA) re-actions is reported. Chromones bearing an alpha,beta-unsaturated carbonyl system at C-3 were used as dienes and a scope of maleimides as dienophiles was investigated. The proposed mechanism involves a DA re-action of 3-benzoylvinylchromones with different maleimides, followed by chromanone ring opening and in situ oxidation. The observed aromatization of DA adducts was accomplished without employment of any oxidizing agent and can be explained by the presence of several acidic protons due to the electron -withdrawing groups (carbonyl groups), affording the 4,6-disubstituted isoindoline-1,3-diones in 15-59% yield. Among tested maleimides, N-phenylmaleimide revealed to be the most reactive dienophile, yield-ing the corresponding 2-phenylisoindoline-1,3-dione in 59% yield. (c) 2022 The Authors. Published by Elsevier B.V.
keywords
PHTHALIMIDE DERIVATIVES; CYTOTOXIC EVALUATION; 3-STYRYLCHROMONES; DIENES
subject category
Chemistry
authors
Nouali, F; Sousa, JLC; Albuquerque, HMT; Mendes, RF; Paz, FAA; Saher, L; Kibou, Z; Choukchou-Braham, N; Talhi, O; Silva, AMS
our authors
Filipe Alexandre Almeida Paz
Principal Researcher
Joana Lia Cardoso de Sousa
Post-Doc Fellowship
Ricardo Faria Mendes
Junior ResearcherProjects
Collaboratory for Emerging Technologies, CoLab (EMERGING TECHNOLOGIES)
acknowledgements
This work received financial support from PT national funds (FCT/MCTES, Fundacao para a Ciencia e a Tecnologia and Ministerio da Ciencia, Tecnologia e Ensino Superior) through the projects: LAQV-REQUIMTE (UIDB/50006/2020 and UIDP/50006/2020) and CICECO - Aveiro Institute of Materials (UIDB/50011/2020 and UIDP/50011/2020), and from the European Union [FEDER funds through the Operational Competitiveness Program (COMPETE2020) POCI-01-0145-FEDER-029767 - Project EpigenGlicON]. Joana Sousa and Helio Albuquerque acknowledge the EpigenGlicON project (POCI-01-0145-FEDER-029767) for their researcher contracts. Ri-cardo Mendes gratefully acknowledges FCT for a Junior Research Position (CEECIND/00553/2017).