Carbon-Carbon Bond Cleavage of .ALPHA.-Hydroxybenzylheteroarenes Catalyzed by Cyanide Ion: Retro-Benzoin Condensation Affords Ketones and Heteroarenes and Benzyl Migration Affords Benzylheteroarenes and Arenecarbaldehydes.
PIDA-mediated intramolecular oxidative C–N bond formation for the direct synthesis of quinoxalines from enaminones
作者:Hong Zhang、Jinhai Shen、Zhenhui Yang、Xiuling Cui
DOI:10.1039/c9ra01200a
日期:——
A intramolecular oxidative C(sp2)–N bond formation mediated by hypervalent iodine(III) to obtain quinoxalines from readily available N-(2-acetaminophenyl)enaminones was developed. A tandem process involving PIDA-mediated intramolecular condensation cyclization and a subsequent elimination was postulated, which was highlyefficient and metal-free under mild conditions. Moreover, flexible structural
开发了一种由高价碘( III ) 介导的分子内氧化C(sp 2 )-N 键形成,以从容易获得的N- (2-乙酰氨基苯基)烯胺酮中获得喹喔啉。假定涉及 PIDA 介导的分子内缩合环化和随后的消除的串联过程,该过程在温和条件下高效且不含金属。此外,具有羰基的喹喔啉的灵活结构修饰对于作为有机合成中的构件进一步转化具有重要意义。
2-Aroylquinoxalines (5, 6), 1-aroylphthalazines (10, 11), and 4-aroylcinnolines (13) were synthesized by using arenecarbaldehydes (2) in the presence of an azolium salt (1) in moderate to good yields. 1,3-Dimethylimidazolium iodide (1a) and sodium sulfinate (7) were also effective catalysts in this aroylation.
VINOT N.; MAITTE P., BULL. SOC. CHIM. FRANCE, 1977, PART. 2, NO 11-12, 1245-1248