A palladium-catalyzed redox-neutral allylic alkylation of indoles with cyclopropyl acetylenes has been disclosed. Various 1,3-diene indolenine framework bearing a quaternary stereocenter at the C3 position were synthesized straightforwardly in good to excellent yields with high regio- and stereoselectivities. The reaction could be further expanded to the dearomatization of naphthols to synthesize functionalized cyclohexadienones with 1,3-diene motifs. The reaction exhibited high atom economy and good functional group tolerance.
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http://dx.doi.org/10.1039/d0ob02103b | DOI Listing |
Acc Chem Res
January 2025
Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Innovative Drug Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China.
ConspectusThe Mannich reaction, involving the nucleophilic addition of an enol(ate) intermediate to an imine or iminium ion, is one of the most widely used synthetic methods for the synthesis of β-amino carbonyl compounds. Nevertheless, the homo-Mannich reaction, which utilizes a homoenolate intermediate as the nucleophilic partner and provides straightforward access to the valuable γ-amino carbonyl compounds, remains underexplored. This can be largely attributed to the difficulties in generation and manipulation of the homoenolate species, despite various homoenolate equivalents that have been developed.
View Article and Find Full Text PDFBioresour Technol
December 2023
Engineering Research Center of the Ministry of Education for Metallurgical Energy Conservation and Emission Reduction, Kunming University of Science and Technology, Kunming 650093, Yunnan Province, PR China; State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming 650093, Yunnan Province, PR China.
This research comprehensively investigates the co-pyrolysis of sewage sludge (SS) and waste tobacco stem (WTS). Various SS and WTS ratios (1:0, 0.75:0.
View Article and Find Full Text PDFEur J Med Chem
November 2023
Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA. Electronic address:
(N)-Methanocarba adenosine derivatives were structurally modified to target 5-HT serotonin receptors as antagonists, predominantly containing branched N-alkyl groups. N-Dicycloalkyl-methyl groups, including their asymmetric variations, as well as 2-iodo, were found to generally favor 5-HTRs, while only N-dicyclohexyl-methyl derivative 35 showed weak 5-HTR affinity (K 3.6 μM).
View Article and Find Full Text PDFJ Org Chem
December 2022
Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh 208 016, India.
A novel organocatalytic cascade approach for the synthesis of spiro-cyclopropyl oxindole derivatives has been developed. The methodology is based on asymmetric vinylogous Michael addition of 4-nitroisoxazole derivatives to -Boc isatylidene malonates followed by intramolecular alkylation. Its remarkable stereocontrol, wide substrate scope, and scalability highlight this new developed strategy.
View Article and Find Full Text PDFEur J Med Chem
March 2022
Clinic of Nuclear Medicine, University Medicine Göttingen (UMG), Germany. Electronic address:
The development of neurodegenerative diseases is associated with cerebral inflammation, which activates resident immune cells of the central nervous system (CNS), namely microglial cells that show an up-regulation of the cannabinoid subtype 2 receptor (CBR) expression. Therefore our work aimed to design and synthesize a radiotracer for the detection of CBR expression by positron emission tomography (PET) allowing an early diagnosis of neurodegenerative diseases. For the development of such a PET tracer, N-alkyl-substituted indole-3-yl-tetramethylcyclopropylketones served as lead structures due to their high CBR potency and selectivity, allowing radiolabeling on the N-alkyl chain.
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