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
Pd(OAc)<sub>2</sub>-catalyzed dehydrogenative C–H activation: An expedient synthesis of uracil-annulated β-carbolinones
作者:Biplab Mondal、Somjit Hazra、Tarun K Panda、Brindaban Roy
DOI:10.3762/bjoc.11.146
日期:——
An intramolecular dehydrogenative C–H activation enabled an efficient synthesis of an uracil-annulated β-carbolinone ring system. The reaction is simple, efficient and high yielding (85–92%).
Regioselective Synthesis of Pyrimidine‐Annulated Spiro Heterocycles by Radical Cyclization
作者:K. C. Majumdar、T. K. Das、M. Jana
DOI:10.1081/scc-200065003
日期:2005.7
Abstract The reaction of 5‐(2‐iodobenzamido)‐1,3‐dialkylpyrimidine‐2,4‐dione with Bu3SnH‐AIBN in refluxing benzene produces spiro‐heterocyclic compounds in 76–85% yield.
Cu(OTf)<sub>2</sub>-Catalyzed Dehydrogenative C-H Activation under Atmospheric Oxygen: An Expedient Approach to Pyrrolo[3,2-<i>d</i>]pyrimidine Derivatives
作者:B. Roy、Somjit Hazra、Biplab Mondal、K. C. Majumdar
DOI:10.1002/ejoc.201300275
日期:2013.7
A new dehydrogenativeC–Hactivation of uracil in an open atmosphere was developed to synthesize pyrrolo-pyrimidines, which are potentially bioactive molecules. This new approach establishes the selective catalytic activity of Cu(OTf)2 to accomplish the uracil C-6–H activation.
Thiophenol mediated radical cyclization: an expedient approach to 2H-pyrrolo[3,2-d]pyrimidines (9-deazaxanthine analogs)
作者:K.C. Majumdar、Shovan Mondal、Debankan Ghosh
DOI:10.1016/j.tetlet.2010.07.163
日期:2010.10
A new efficient route for the synthesis of substituted 2H-pyrrolopyrimidines (9-deazaxanthine analogs) via thiophenol mediated radical cyclization has been achieved. The stereochemistry of the newly synthesised compounds has been settled from NOE data. (C) 2010 Elsevier Ltd. All rights reserved.