Synthesis of 3-substituted 2-trifluomethyl imidazo[1, 2-a]pyridine through [3+2] cycloaddition of pyridinium ylide with trifluoroacetonitrile. (23rd November 2022) - Hong, Biqiong
Graphical abstract: Highlights: A general method for synthesis of 2-trifluomethyl imidazo[1, 2- a ]pyridines was developed. The use of 2, 2, 2-trifluoroacetaldehyde O -(aryl)oxime as convenient precursor of trifluoroacetonitrile. A variety of functional groups were tolerated. Abstract: A general approach to prepare 2-trifluoromethyl imidazo[1, 2- a ]pyridines by a [3+2] cycloaddition of pyridinium ylide with trifluoroacetonitrile is described. By using 2, 2, 2-trifluoroacetaldehyde O-(aryl)oxime as convenient precursor of trifluoroacetonitrile, the reaction exhibits a broad substrate scope of pyridinium ylides. The process is a scalable method for the synthesis of potentially bioactive class of 2-trifluoromethyl imidazo[1, 2- a ]pyridines.