Nature of the Nucleophilic Oxygenation Reagent Is Key to Acid-Free Gold-Catalyzed Conversion of Terminal and Internal Alkynes to 1,2-Dicarbonyls
Alexey Yu. Dubovtsev*, Nikolay V. Shcherbakov, Dmitry V. Dar'in and Vadim Yu. Kukushkin*
*Saint Petersburg State University, Universitetskaya Nab. 7/9, 199034 Saint Petersburg, Russian Federation, Email: a.dubovtsevspbu.ru, v.kukushkinspbu.ru
A. Yu. Dubovtsev, N. V. Shcherbakov, D. V. Dar'in, V. Yu. Kukushkin, J. Org. Chem., 2020, 85, 745-757.
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2,3-Dichloropyridine N-oxide as oxygen transfer reagent enables gold(I)-catalyzed oxidation of alkynes to 1,2-dicarbonyls in the absence of any acid additives and under mild conditions. The developed strategy is also effective for ynamides, alkynyl ethers/thioethers, and substrates bearing highly acid-sensitive groups. A one-pot heterocyclization provides six-membered azaheterocycles.
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A. Y. Dubovtsev, D. V. Dar'in, V. Y. Kukushkin, Org. Lett., 2019, 21, 4116-4119.