A cascade synthesis of 2-aminothiochromones from 2-fluorophenyl ketone and thiocarbonyldiimidazole.

A highly efficient cascade synthesis of various substituted 2-aminothiochromones was developed. The commercially available thiocarbonyldiimidazole (TCDI) acted as a key precursor in the construction of a sulfur-containing scaffold from 2-fluorophenyl ketone. Subsequent conjugated addition-elimination resulted in the corresponding 2-aminothiochromones under mild conditions. This simple protocol tolerates a broad range of functional groups and provides concise access to various 2-aminothiochromones in good to excellent yields (up to 94%).