Natural Phosphate Modified with Sodium Nitrate: New Efficient Catalyst for the Construction of a Carbon-Sulfur and Carbon-Nitrogen Bonds

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.