Abstract

The modification on natural phosphate (NP) with sodium nitrate by calcination catalyzed Michael addition of mercaptans and amines to chalcone derivatives with high yields under mild reaction conditions. By-products of usual undesirable reaction in Michael condensation such as 1,2-addition, bis-addition and polymerization are not observed. The work-up procedure is simplified by simple filtration with the use of Na/NP-2. This catalyst is used for the facile synthesis of β-amino acid and β-amino diacid under heterogeneous conditions.

Keywords: natural phosphate, carbon-sulfur bond, carbon-nitrogen bond, amino acid, amino diacid, heterogeneous catalysis, recyclable catalyst