RT journal article
T1 Microwave-Assisted Rearrangement of Costunolide Catalyzed by Palladium(II)
A1 Macías Domínguez, Francisco Antonio
A1 S. Alvarenga, Elson
A1 García Galindo, Juan Carlos
A1 González Molinillo, José María
A1 Cerceau, C.I.
A2 Química Orgánica
K1 Cope reaction
K1 sesquiterpene lactone
K1 wheat coleoptile
K1 rearrangement reaction
AB The structure of costunolide was modified before conducting the Cope rearrangement under thermal conditions. This modification was undertaken to block the highly reactive Michael acceptor α-methylene-γ-lactone, thus preventing side reactions at high temperatures. In this work, the reaction was performed under heating or microwave irradiation using costunolide, not its modified version. Rates of Cope reactions catalyzed by palladium(II) assisted by microwave were substantially enhanced. The rearrangements of costunolide to elemanolide, eudesmanolides, and germacranolide were catalyzed by palladium acetate, bis(benzonitrile)palladium dichloride, and a mixture of both organometallics. Rates of microwave promoted rearrangements of costunolide were six times faster than the reactions assisted by heating. The best success rate for elemanolide (7) was obtained using a mixture of Pd(OAc)2 and (NCPh)2PdCl2. In this case, compound 7 was obtained in a yield of 34%, while the other sesquiterpene lactones were formed only in trace amounts. The reaction products were isolated using semi-preparative high performance liquid chromatography and further purified through sequential analytical high performance liquid chromatography. Bioactivity profiles that used etiolated wheat coleoptiles were conducted for compounds 6, 7, and 9. The tested compounds presented very high phytotoxicity, with inhibition up to 97%.
PB SOC BRASILEIRA QUIMICA
SN 1678-4790
YR 2024
FD 2024
LK http://hdl.handle.net/10498/33632
UL http://hdl.handle.net/10498/33632
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 10-nov-2026