resumo
The Henry-type Barbier addition of bromonitromethane to 3-formylchromone, immediately followed by acetylation and concomitant elimination to afford nitroalkenes in excellent yield and total (E)-selectivity is described. Cycloaddition of N-methylhydrazones with the obtained nitroalkenes gave the corresponding pyrazoles. Among the prepared pyrazoles, derivative 6j, which contains a catechol moiety, showed simultaneously a potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity and an alpha-glucosidase inhibitory activities. (C) 2016 Elsevier Ltd. All rights reserved.
palavras-chave
ALPHA-GLUCOSIDASE INHIBITORS; ANTIOXIDANT ACTIVITY; PYRAZOLE DERIVATIVES; MEDIATED REACTION; AGENTS; NITROOLEFINS; IDENTIFICATION; ANTIBACTERIAL; HYDRAZONES; SCAVENGERS
categoria
Chemistry
autores
Soengas, RG; Silva, VLM; Ide, D; Kato, A; Cardoso, SM; Paz, FAA; Silva, AMS
nossos autores
agradecimentos
Thanks are due to University of Aveiro and FCT/MEC for the financial support to the QOPNA research project (FCT UID/QUI/00062/2013) and CICECO Aveiro Institute of Materials (FCT UID/CTM/50011/2013) through national founds and where applicable co-financed by the FEDER, within the PT2020 Partnership Agreement, and also to the Portuguese NMR Network. We further wish to thank CICECO for specific funding toward the purchase of the single-crystal X-ray diffractometer. Raquel G. Soengas and Vera L.M. Silva thank the projects Harvesting the Energy of the Sun for a Sustainable Future (MI-PI-6-ARH/2014) and New Strategies Applied to Neuropathological Disorders (CENTRO-07-ST24-FEDER-002034), respectively, co-funded by QREN, 'Mais Centro-Programa Operacional Regional do Centro' and EU, FEDER for their Assistant Research positions.