SmCl3-catalyzed C-acylation of 1,3-dicarbonyl compounds and malononitrile.

A recyclable, convenient, and efficient catalytic system for C-acylation of 1,3-dicarbonyl compounds and malononitrile with acid chlorides has been developed, giving moderate to excellent yields under mild conditions. This is the first catalytic example of such reactions. In addition, by applying this protocol as the key step, 3,5-disubstituted-1H-pyrazole-4-carboxylate can easily be synthesized in high yields in a one-pot procedure.