Application of a Regioselective Mannich Reaction on Naringenin and its Use in Fluorescent TLabeling

novel strategy for site-specific fluorescent labeling on naringenin (1) was established by a new direct Mannich reaction in combination with a Huisgen [3+2]-cycloaddition reaction. High ­regioselectivity was observed for direct Mannich reactions on ­naringenin and several other flavonones using a variety of amines and aldehydes