A variety of functionalized N-alkylated carbazolones were prepared via N-alkylation of 3-(arylamino)cyclohex-2-enones followed by an intramolecular oxidative coupling mediated by Pd(OAc)2 under an oxygen atmosphere. This approach adopts an inverted sequence, consisting of the conventional annulation and subsequent N-alkylation.
An Improved Method for the Synthesis of Carbazolones by Palladium/Copper-Catalyzed Intramolecular Annulation of N-Arylenaminones
作者:Jing-Hua Li、Bojie Weng、Rui Liu
DOI:10.1055/s-0030-1258141
日期:2010.9
via the condensation of arylamines with 1,3-cyclodiketones followed by intramolecular oxidative cyclization catalyzed by palladium acetate and copper acetate in ethanol under an oxygen atmosphere was established. The improved method has the advantage of easily available starting materials and affords good yields. carbazolones - intramolecular oxidative cyclization - oxygen - palladium acetate- copper
An Efficient Synthesis of Pyrroline-Fused Acridine Derivatives Catalyzed by Silica Sulfuric Acid
作者:Ming-Hua Hu、Wei Lin、Cheng-Pao Cao、Zhi-Bin Huang、Da-Qing Shi
DOI:10.1002/jhet.2023
日期:2014.8
A simple and efficientsynthesis of pyrrolo[2,3,4-kl]acridine-1-one derivatives via the cascade reaction of isatins with enaminones catalyzed by silicasulfuricacid (SSA) has been established. In this reactions, SSA shows a highly catalytic nature: easy to handle procedure, short reaction time, recycle exploitation, insensitivity to air and moisture, and excellent isolated yields. The catalyst could
Highly Regioselective and Chemoselective [3 + 3] Annulation of Enaminones with <i>ortho-</i>Fluoronitrobenzenenes: Divergent Synthesis of Aposafranones and Their <i>N</i>-Oxides
regioselective and chemoselective divergent synthesis of highly functionalized aposafranones and their N-oxides has been developed from the [3 + 3] annulation of enaminones with o-fluoronitrobenzenenes. This novel synthetic strategy offers an alternative method for the construction of aposafranones and their N-oxides are meaningful in the fields of both biology and organic synthesis. The established
organocatalysis from commonly used o-hydroxystyrenes undergo enantioselective cyclization with dimedone-derived enaminones, to form biologically important tetrahydroxanthenes in high yields and good enantioselectivities (up to 88% yield, 95:5 er). The reaction proceeds in chlorobenzene in the presence of a chiral phosphoric acid (CPA) at 110 °C. The reaction scope with regard to various ring-substituted o-hydroxystyrenes