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.
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.
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.