Thermal Cyclization of Ketene Dithioacetals: A Convenient Synthetic Route to Substituted 2(1<i>H</i>)-Quinolinones and 2(1<i>H</i>)-Pyridones
作者:Chwang Siek Pak、Eun Bok Choi
DOI:10.1055/s-1992-26361
日期:——
Acyl(arylcarbamoyl)ketene dithioacetals 2 and acyl(1-alkenylcarbamoyl)ketene dithioacetals 5 obtained from the corresponding ß-oxo amides 1, 4 were thermally cyclized to give various 3-acyl-4-alkylthio-2(1H)-quinolinones 3, and 3-acyl-4-alkylthio-5-aryl-2(1H)-pyridones 6, respectively, depending on the substituent of the amide group.
Synthesis of β-Lactam from Acyl(Arylcarbamoyl)-<i>S,S</i>-bis(alkylketene) Dithioacetal: Revised Structure of the Product from Thermal Cyclization of Acyl(Arylcarbamoyl)-<i>S,S</i>-bis(alkylketene) Dithioacetal
The structure of the quinolinone obtained from thermal cyclization of ketene dithioacetal has been revised by X-ray crystallographic analysis as 4-quinolinone instead of the previously reported 2-quinolinone. In the course of study on the mechanistic feature of the thermal cyclization, highly substituted β-lactams were obtained by alkylating β-lactam anion with MEMCl, MOMCl, or MeI in the presence of NaH.
Palladium-Catalyzed C–S Bond Cleavage with Allenoates: Synthesis of Tetrasubstituted 2-Alkenylfuran Derivatives
作者:Quannan Wang、Zhuqing Liu、Jiang Lou、Zhengkun Yu
DOI:10.1021/acs.orglett.8b02253
日期:2018.10.5
Palladium-catalyzed C–S cleavage of tetrasubstituted internal alkene α-oxo ketene dithioacetals was realized with allenoates as the coupling partners, efficiently affording tetrasubstituted 2-alkenylfuran derivatives with excellent regioselectivity under mild conditions. Allenoates acted as C1 synthons in the desulfurative [4 + 1] annulation.
Selectfluor-Promoted Intramolecular N–S Bond Formation of α-Carbamoyl Ketene Dithioacetals in the Presence of Water: Synthesis of Multifunctionalized Isothiazolones
作者:Zheng Liu、Youkun Wang、Jianfeng Huo、Xiao-Jun Li、Shengnan Li、Xiaoning Song
DOI:10.1021/acs.joc.0c03036
日期:2021.4.16
annulation of α-carbamoyl ketenedithioacetals has been developed in the presence of H2O and metal-free conditions. Notably, the experimental results reveal that H2O was crucial to the formation of new N–S bonds and the elimination of alkyl group from the sulfur atom. This protocol provides readily prepared substrates and possesses good functional group tolerance, mild reaction conditions, and operational