A New Powerful Approach to Multi-Substituted 3(2H)-Furanones via Brønsted Acid-Catalyzed Reactions of 4-Diazodihydrofuran-3-ones
作者:Valerij Nikolaev、Jury Medvedev、Dmitrii Semenok、Xenia Azarova、Liudmila Rodina
DOI:10.1055/s-0036-1588304
日期:——
4-diazo-3(2H)furanones with Brønsted acids (TFA, TsOH, etc.) causes elimination of nitrogen accompanied by 1,2-nucleophilic rearrangement, giving rise to exclusive formation of 4,5-dialkyl(diaryl)-substituted 3(2Н)-furanones, ring-fused 3(2H)-furanones, and phenanthro[9,10-b]furan-3(2H)-ones in yields of up to 99%. The reaction is a new highly efficient way for the synthesis of multisubstituted 3(2Н)furanones
Acid‐catalyzed decomposition and stability of diazofuranones: Experimental and mechanistic study
作者:Dmitrii Semenok、Andrey S. Mereshchenko、Jury Medvedev、Giorgio Visentin
DOI:10.1002/poc.4038
日期:2020.3
Reactions of substituted 4‐diazotetrahydrofurane‐3‐ones with various acids (pKa < 3) irrespective of acid strength give rise to elimination of nitrogen with subsequent 1,2‐nucleophilic migration of aryl (alkyl) groups from C‐5 to C‐4 position of heterocyclic core with quantitative formation of regioisomeric 3(2Н)furanones (yields up to 99%). Regioselectivity of this acid‐catalyzed process increases with
不管酸强度如何,取代的4-重氮四氢呋喃-3-酮与各种酸(p K a <3)的反应都会导致氮的消除,随后芳基(烷基)基团从C-5到C的1,2-亲核迁移杂环芯相定量形成区域异构体3(2 -4位置Н)呋喃酮(产率高达99%)。该酸催化过程的区域选择性随溶剂极性的降低而增加,并且强烈取决于芳基中取代基的性质。该反应通过中间体RN 2 +的建议机理 由于重氮酮在不同溶剂中酸稳定性的计算和实验数据之间的一致性好,因此在PBE0 / 6-31 + G(d)官能团上通过密度泛函理论(DFT)计算确认了阳离子。
Surprising secondary photochemical reactions observed on conventional photolysis of diazotetrahydrofuranones
作者:Valerij A. Nikolaev、Olesja S. Galkina、Jochim Sieler、Ludmila L. Rodina
DOI:10.1016/j.tetlet.2010.03.050
日期:2010.5
during direct photolysis of regioisomeric 2,2-dimethyl-5,5-diphenyl and 5,5-dimethyl-2,2-diphenyl-substituted 3-diazotetrahydrofuran-4-ones in THF is dictated by photochemical cycloelimination of the originally formed (1,1-dimethyl-2-oxa-3,3-diphenyl-propano)ketene and oxetanecarboxylic acid derivatives to yield benzophenone. The latter, under subsequent UV irradiation of the reaction mixture, initiates