A catalyst-free C-H hydroarylation of coumarin derived ortho-quinone methide (o-QM) with electron rich arenes in glycerol

An efficient, catalyst-free approach for C-H hydroarylation of in situ generated ortho-quinone methide (o-QM) with electron rich arenes (tertiary aryl amines) in glycerol has been developed. Several C-3-benzylated 4-hydroxycoumarin and 4-hydroxypyrone have been synthesized in good to excellent yields under mild conditions.