Electrophilic ipso-iodocyclization of N-(4-methylphenyl)propiolamides:: Selective synthesis of 8-methyleneazaspiro[4,5]trienes

[GRAPHICS] A novel and selective method for the synthesis of 8-methylenespiro[4,5]trienes via intramolecular electrophilic ipsoiodocyclization of N-(4-methylphenyl)propiolamides has been developed. In the presence of ICI or I-2, 8-methylene-1-azaspiro[4,5]trienes were selectively prepared from the electrophilic ipso-iodocyclization of N-(4-methylphenyl)propiolamides in moderate to good yields.