A Short Route to the Synthesis of Pyrrolocoumarin and Pyrroloquinolone Derivatives by Sonogashira Cross-Coupling and Gold-Catalyzed Cycloisomerization of Acetylenic Amines
The syntheses of pyrrolocoumarin and pyrroloquinolone derivatives have been achieved in excellent yields from the acetylenic amines by gold-catalyzed cycloisomerization in the absence of any silver salts or any other bases. The acetylenic amines were in turn obtained by Sonogashira coupling of the corresponding coumarin and quinolone derivatives. coumarin - quinolone - Sonogashira coupling - gold catalysis
An Efficient Synthesis of Pyrrolocoumarins and Pyrroloquinolones by Acid-Catalysed Cyclisation of Acetylenic Amines in Water
作者:K. Majumdar、Sudipta Ponra、Somjit Hazra、B. Roy
DOI:10.1055/s-0030-1259990
日期:2011.5
A simple H+-catalysed cyclisation of acetylenic amines for the synthesis of pyrrolocoumarins and pyrroloquinolones under conventional heating or microwave irradiation has been achieved. The reaction requires inexpensive catalyst and simple yet clean reaction conditions and offers potentially bioactive heterocycles in 82-95% yields. pyrrolocoumarin - pyrroloquinolone - Brønsted acid catalysis - intramolecular
Iron/Palladium-Catalyzed Intramolecular Hydroamination: An Expedient Synthesis of Pyrrole-Annulated Coumarin and Quinolone Derivatives
作者:K. Majumdar、Nirupam De、B. Roy
DOI:10.1055/s-0030-1258311
日期:2010.12
A highly efficient intramolecular hydroamination reaction of heterocycle-centered aminoalkynes using both substituted and free amines catalyzed by PdCl2/FeCl3 catalytic system to form the biologically important pyrrolocoumarin and pyrroloquinolone derivatives is reported. The use of both aliphatic and aromatic substituted alkynes with different heterocyclic skleton in this strategy demonstrated the
Montmorillonite K-10 Catalyzed, Microwave-Assisted Cyclization of Acetylenic Amines: An Efficient Synthesis of Pyrrolocoumarins and Pyrroloquinolones
作者:K. Majumdar、Sudipta Ponra、Tapas Ghosh
DOI:10.1055/s-0031-1291161
日期:2012.7
Abstract A microwave-assisted montmorilloniteK-10 catalyzed synthesis of pyrrolocoumarins and pyrroloquinolones from acetylenic amine is described. The reaction utilizes montmorilloniteK-10 as an inexpensive, recyclable, and environmentally benign acid catalyst. Reactions were completed in few minutes under microwaveirradiation and provided excellent yields. The efficient and eco-friendly catalyst