A green and mild protocol for the dehydrogenative olefination of cyclic enaminones was devised via palladium catalysis at room temperature using oxygen as the terminal oxidant. The synthetic utility of the olefinated cyclic enaminones afforded a series of unique 1,3,5-trisubstituted benzenes via an unanticipated Diels-Alder tandem reaction. The broad substrate scope and good yields achieved with this new protocol provide an alternative pathway for arene functionalization.
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http://dx.doi.org/10.1002/adsc.201300904 | DOI Listing |
J Org Chem
June 2024
Enamine Limited, 78 Winston Churchill Street, 02094 Kyiv, Ukraine.
A conceptual strategy for a formal α-alkylation of α-methylene ketones was developed. Diverse 1° and 2° alkyl substituents were generated in the α-position of various ketones via synthesis of enaminone (step 1) and treatment with organomagnesium (step 2) with subsequent catalytic hydrogenation (step 3, 1° alkyl) or organocopper reagents (step 4, 2° alkyl). Tolerance toward ester, Boc-protected amine, and α-fluoro-substituted ketone moieties was demonstrated.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2024
Department of Chemistry, Indian Institute of Technology, Kanpur 208016, India.
Acridone, a cyclic analogue of benzophenone that undergoes efficient intersystem crossing (ISC) to the triplet-excited state with near-unity quantum yield, was elaborated as a 3-connecting triacid linker, i.e., , to develop a photocatalytic metal-organic framework (MOF) for energy transfer applications; the triacid linker inherently features concave shapes, an attribute that is important for the construction of MOFs with significant porosity.
View Article and Find Full Text PDFPhotochem Photobiol
November 2023
Department of Chemistry, Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio, USA.
The irradiation of β-enaminones, generated in situ from cyclic 1,3-diketones and activated alkenes leads to polyheterocyclic skeletons. The photoproduct chemoselectivity depends on the type of cyclic 1,3-diketones employed viz., 2-acetylcyclopentanone and 2-acetylcyclohexanone.
View Article and Find Full Text PDFOrg Biomol Chem
December 2023
Key Laboratory of Organo-Pharmaceutical Chemistry of Jiangxi Province, Gannan Normal University, Ganzhou 341000, P.R. China.
An eco-friendly and metal-free method for the synthesis of tetrahydrodibenzo[,][1,8]naphthyridin-1(2)-ones was established. Quinoline-derived dipolarophiles and cyclic enaminones as starting materials undergo a 1,4-Michael addition/SAr tandem annulation reaction affording the target products. This approach features transition metal-free conditions, good functional group tolerance and operational simplicity.
View Article and Find Full Text PDFJ Am Chem Soc
October 2023
Department of Chemistry, University of Oxford, Chemical Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, U.K.
Reactions capable of transposing the oxidation levels of adjacent carbon atoms enable rapid and fundamental alteration of a molecule's reactivity. Herein, we report the 1,2-transposition of the carbon atom oxidation level in cyclic and acyclic tertiary amides, resulting in the one-pot synthesis of 1,2- and 1,3-oxygenated tertiary amines. This oxidation level transfer was facilitated by the careful orchestration of an iridium-catalyzed reduction with the functionalization of transiently formed enamine intermediates.
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