Pharmaceutical and Biologically-Active Compounds Research Laboratory, Department of Chemistry, Iran University of Science & Technology, Tehran 16846-13114, Iran.
Pharmaceutical and Biologically-Active Compounds Research Laboratory, Department of Chemistry, Iran University of Science & Technology, Tehran 16846-13114, Iran.
Int J Biol Macromol. 2016 Jun;87:172-9. doi: 10.1016/j.ijbiomac.2016.01.080. Epub 2016 Feb 1.
Sodium alginate, a naturally occurring macromolecule, in its granular form and without any post-modification was found to be an efficient and recoverable bifunctional heterogeneous organocatalyst for the domino synthesis of various 2-amino-3-cyano-4H-pyran annulated derivatives through three-component condensation of different aldehydes, malononitrile and diverse 1,3-dicarbonyl compounds under mild conditions. Corresponding 4H-pyran derivatives were obtained in high to excellent yields after 25-150min stirring in 2mL EtOH under reflux conditions in the presence of 10mol% of sodium alginate, equimolar amounts of aldehydes, malononitrile and 1,3-dicarbonyl compounds. The catalyst was easily separated from the reaction mixture to obtain desired products in excellent purity as shown by FTIR and (1)H NMR spectroscopic methods. Avoiding the use of any transition metal, one-pot and multi-component procedure catalyzed by a renewable biopolymer, the reusability of the catalyst, broad substrate scope and operational simplicity are important features of this methodology for preparation of medicinally important compounds.
海藻酸钠是一种天然存在的高分子化合物，以颗粒形式存在且未经任何后修饰，被发现是一种高效且可回收的双功能多相有机催化剂，可通过不同醛、丙二腈和各种 1,3-二羰基化合物的三组分缩合，在温和条件下一锅法合成各种 2-氨基-3-氰基-4H-吡喃并稠合衍生物。在 2mL EtOH 中回流条件下，用 10mol%的海藻酸钠、等摩尔量的醛、丙二腈和 1,3-二羰基化合物，搅拌 25-150min 后，可得到高至优异收率的相应 4H-吡喃衍生物。通过 FTIR 和（1）H NMR 光谱方法证明，催化剂很容易从反应混合物中分离出来，以优异的纯度获得所需产物。该方法避免使用任何过渡金属，一锅多组分反应由可再生生物聚合物催化，催化剂可重复使用、底物范围广泛且操作简单，这些都是该方法在制备具有重要药用价值的化合物方面的重要特点。
