Catalyst-Free Regioselective C-3 Nitrosation of Imidazopyridines with tert-Butyl Nitrite under Neutral Conditions
摘要:
We have successfully developed a novel and efficient catalyst-free method for the synthesis of 3-nitroso-substituted imidazopyridines, from readily available imidazo[1,2-a]pyridines and tert-butyl nitrite, in good to excellent yields. Importantly, the use of transition-metal catalysts, stoichiometric amounts of acids, and toxic or potentially dangerous oxidants is avoided. This easy and practical method complements nitrosation reactions by expanding the scope and practicality, and should attract much attention in synthetic and pharmaceutical chemistry.
NaNO<sub>2</sub>/I<sub>2</sub>-Mediated Regioselective Synthesis of Nitrosoimidazoheterocycles from Acetophenones by a Domino Process
作者:Sushobhan Mukhopadhyay、Shashikant U. Dighe、Shivalinga Kolle、Praveen K. Shukla、Sanjay Batra
DOI:10.1002/ejoc.201600553
日期:2016.8
regioselective synthesis of nitrosoimidazoheterocycles from the reaction of 2-aminopyridines and acetophenones in the presence of NaNO2 and I2 is described. The reaction is suggested to proceed by a domino process involving sequential imine formation, iodination, iodide displacement by the nitro group, and finally intramolecular cyclization. Reaction of these 3-nitrosoimidazo[1,2-a]pyridines with aldehydes