A rhodium-catalyzed transannulation via ring-opening of N-(per)fluoroalkyl-substituted 1,2,3-triazoles followed by cycloaddition with different nitriles, enol ethers, isocyanates and silyl ketene acetals under microwave heating provided a highly efficient route to previously unreported N-(per)fluoroalkyl-substituted imidazoles, pyrroles, imidazolones and pyrrolones, respectively. These reactions were found to be applicable to the synthesis of a variety of 5-membered heterocycles bearing different (per)fluoroalkyl substituents as well as both electron-donating and electron-withdrawing groups attached to the heterocyclic core.
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http://dx.doi.org/10.1039/c8cc01446a | DOI Listing |
J Org Chem
September 2022
Technology for Organic Synthesis Department, Ural Federal University, 19 Mira Street, Yekaterinburg 620002, Russia.
The reactivity of readily available 4,5-fused-1-sulfonyl-1,2,3-triazoles was examined in the Rh(II)-catalyzed transannulation reaction with nitriles. We have come across the interesting observation that 1-sulfonyl cycloalkeno[][1,2,3]triazoles that possess β-hydrogens resist intramolecular β-hydride migration and could serve as a new source of Rh-iminocarbenoids for intermolecular Rh(II)-catalyzed transannulation reactions. As a result, 1-sulfonyl cyclohexeno-, cyclohepteno-, dihydropyrano-, 5-phenyltetrahydrobenzo-, and 4,5-dihydronaphtho[]imidazoles were synthesized from various nitriles in good yields.
View Article and Find Full Text PDFOrg Lett
August 2021
Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, NMPA Key Laboratory for Research and Evaluation of Innovative Drug, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China.
Described here is a selective synthesis of 2,3-dihydropyrrole-fused -glycosides through rhodium-catalyzed denitrogenative transannulation of -sulfonyl-1,2,3-triazoles with glycals. A series of pyrroline-fused -glycosides are afforded in moderate to excellent yields with exclusive regioselectivity and stereoselectivity. Functional application of such a resultant product by oxidative addition and epoxidation is also explored.
View Article and Find Full Text PDFOrg Biomol Chem
July 2021
Department of Chemistry, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Xiasha West Higher Education District, Hangzhou, 310018, China.
A facile synthesis of multi-functionalized benzothiazonine was achieved by the rhodium-catalyzed denitrogenative annulation of 1-sulfonyl-1,2,3-triazole and thiochromone. In view of the excellent atom economy, broad substrate scope and easy availability of starting materials, the protocol provided an efficient strategy for the construction of medium N,S-heterocycles.
View Article and Find Full Text PDFOrg Biomol Chem
April 2021
Department of Organic Chemistry, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, P. R. China.
A rhodium-catalyzed denitrogenative formal (3 + 3) transannulation of 1,2,3-thiadiazoles with alk-2-enals is achieved, producing 2,3-dihydrothiopyran-4-ones in moderate to excellent yields. An inverse KIE of 0.49 is obtained, suggesting the reversibility of the oxidative addition of thioacyl Rh(i) carbenes to alk-2-enals.
View Article and Find Full Text PDFBeilstein J Org Chem
February 2021
Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo náměstí 2, 166 10 Prague 6, Czech Republic.
The rhodium-catalyzed transannulation of perfluoroalkyl-1,2,3-triazoles with aromatic and aliphatic terminal alkynes under microwave heating conditions afforded perfluoroalkyl-3,4-disubstituted pyrroles (major products) and fluoroalkyl-2,4-disubstituted pyrroles (minor products). The observed selectivities in the case of the reactions with aliphatic alkynes were high.
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