Facile Regioselective Synthesis of Functionalized Heterocycle-Tethered Spiro Compounds via an Intramolecular Electrophilic Ipso-Iodocyclization Process
作者:K. Majumdar、Tapas Ghosh、Pranab Shyam
DOI:10.1055/s-0031-1289526
日期:2011.11
A general, regioselective, and efficient intramolecular electrophilic ipso-iodocyclization of a series of N-alkyl-N-aryl phenylpropiolamides in the presence of I2 (molecular iodine) and NaHCO3 via 5-endo-dig mode of cyclization has been developed for the synthesis of hitherto unreported coumarin, quinolone, and pyrimidine-annelated heterocycliccompounds in excellent yields (84-92%). The development
A new synthetic protocol has been developed for the arylation of secondary and N-alkylated amide Heck precursors by the implementation of the palladium-catalyzed intramolecular Heck reaction strategies.
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
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
Novel Synthesis of Heterocycle-Annulated Azocine Derivatives of Biological Relevance by Aromatic Aza-Claisen Rearrangement and Intramolecular Heck Reaction
A synthetic strategy based on the sequential application of an aromatic aza-Claisenrearrangement and an intramolecular Heck reaction sequence as the key steps has been developed for the synthesis of various hitherto unreported coumarin- and quinolone-annulated benzazocine derivatives in excellent yields. aza-Claisenrearrangement - Heck reaction - benzazocine - coumarin - quinolone - palladium catalyst