A robust transition-metal-free one-step strategy for the synthesis of ynamides from sulfonamides and ( Z)-1,2-dichloroalkenes or alkynyl chlorides is presented. This method is not only effective for internal ynamides but also amenable for terminal ynamides. Various functional groups, even the vinyl moiety, are compatible, and thus, this strategy offers the opportunity for further functionalization.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acs.joc.8b03192 | DOI Listing |
Chemistry
July 2024
School of Natural Science, Department Chemie, Technische Universität München, Lichtenbergstr. 4, Garching bei München, 85748, Germany.
Syntheses of (partially) aromatic nitrogen heterocycles increasingly rely on transition-metal catalyzed C-C- and C-N-cross-coupling reactions. Here we describe a different approach to the synthesis of indolines by a domino C(sp)-H activation, 1,2-addition, and defluorinative SAr-cyclization sequence to provide the target 1,2-diarylindolines (1,2-diaryl-2,3-dihydroindoles) from ortho-fluorinated methyl-arenes and N-aryl imines (benzylidene anilines) in a cyclocondensation that is mediated by potassium hexamethyldisilazide (KHMDS) as base exclusively. This transition-metal-free process via C-H and C-F bond activation provides a one-step entry into a wide array of indoline scaffolds (43 examples, up to 96 % yield).
View Article and Find Full Text PDFJ Org Chem
September 2023
Yunnan Key Laboratory of Metal-Organic Molecular Materials and Device, School of Chemistry and Chemical Engineering, Kunming University, Kunming 650214, China.
An electrochemical or photoelectrochemical regioselective polyfluoroalkylation/cyclization cascade of 3-aza-1,5-dienes with sodium fluoroalkanesulfinates is presented. This protocol proceeds with a broad substrate scope and good functional group tolerance under mild, oxidant-free, transition-metal-free, and electrolyte-free conditions to provide 3-polyfluoroalkylated 4-pyrrolin-2-ones in one step from readily available -vinylacrylamides, and it is readily scalable to the Gram scale.
View Article and Find Full Text PDFOrg Biomol Chem
March 2023
Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Key Laboratory of Molecular-Based Materials, School of Chemistry and Materials Science, Anhui Normal University, Wuhu, Anhui 241000, China.
A method for the hydroalkynylation and catalytic cyclization reactions of hexadehydro-Diels-Alder-derived benzynes is described. Diethynylbenzene derivatives are generated in a one-step reaction trimethylsilyl-alkyne groups with benzyne formed by heating the appropriate tetrayne substrate. Trimethyl(phenylethynyl)silane loses TMS and binds to the electron-deficient site on HDDA-derived benzynes, and then phenanthrene was synthesized under mild reaction conditions by transition-metal-free, base promoted intramolecular cyclization.
View Article and Find Full Text PDFChemistry
March 2023
Department of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
A one-step method for the conversion of nitroarenes into phenols under operationally simple, transition-metal-free conditions is described. This denitrative functionalization protocol provides a concise and economical alternative to conventional three-step synthetic sequences. Experimental and computational studies suggest that nitroarenes may be substituted by an electron-catalysed radical-nucleophilic substitution (S 1) chain mechanism.
View Article and Find Full Text PDFJ Org Chem
December 2022
National Engineering Research Center for Carbohydrate Synthesis, Key Lab of Fluorine and Silicon for Energy Materials and Chemistry of Ministry of Education, Key Laboratory for Green Chemistry of Jiangxi Province, Jiangxi Normal University, Nanchang 330022 Jiangxi, China.
A straightforward protocol for the synthesis of 11-trifluoromethylated dibenzodiazepines has been developed via TBAC-induced trifluoromethylation/cyclization of -isocyanodiaryl amines using Togni's reagent as the trifluoromethyl source. This is the first report on the one-step construction of CF-containing dibenzodiazepine drug skeletons. Additionally, a series of 11-trifluoromethylated dibenzodiazepines were afforded in moderate to excellent yields under transition-metal-free conditions.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!