A facile and versatile catalyst-free method for the preparation of a wide range of
pentasubstituted pyrroles has been reported using four-component reactions of arylglyoxal
monohydrate, β-keto esters, amines, and various cyclic 1,3-dicarbonyls under mild
reaction conditions. Employing this methodology, pseudo seven-component reactions
have also been achieved in the case of p-phenylenediamine to provide conjugated bispyrroles with arene spacers.
Key words
multicomponent reactions - β-keto esters - arylglyoxals - cyclic 1,3-dicarbonyls -
pentasubstituted pyrroles