Microwave-assisted Palladium catalysed C-H acylation with aldehydes. Synthesis and diversification of 3-acylthiophenes
View/ Open
Date
2021-12-22Author
Santiago Alvarez, Carlos
Jiménez de Aberásturi González, Xabier
Leicea, Eztizen
Lete, Marta G.
Sotomayor Anduiza, María Nuria
Lete Expósito, María Esther
Metadata
Show full item record
Organic & Biomolecular Chemistry 20 : 852-861(2022)
Abstract
The use of MW allows the efficient palladium(II)-catalysed C-3 acylation of thiophenes with aldehydes via C(sp2)-H activation for the synthesis of (cyclo)alkyl/aryl thienyl ketones (43 examples). Compared to standard thermal conditions, the use of MW reduces the reaction time (15 to 30 min vs. 1 to 3 hours), leading to improved yields of the ketones (up to 92%). Control of positional selectivity is achieved by 2-pyridinyl and 2-pyrimidyl ortho-directing groups at C-2 of the thiophene scaffold. To show the synthetic applicability, selected ketones were subjected to further transformations, including intramolecular
reactions to directly embed the directing-group in the core-structure of the new molecule