高效可循环使用的季铵盐负载氯化钯催化的Biginelli反应

以季铵盐负载氯化钯为催化剂，由芳香醛、α,β 二羰基化合物、尿素(硫脲)合成了3，4 二氢嘧啶 2(1H) 酮/硫酮化合物. 结果表明:该合成方法使用季铵盐负载氯化钯为催化剂，在中性条件下合成目标化合物的产率最高. 催化剂PdCl_2/BTEACl是一种用量少、均相、中性、高效、可重复使用的催化Biginelli反应的催化体系.该方法反应条件温和、操作简单、实际应用性强，催化剂经简单分离后可循环使用. HPLC测定结果证实此催化体系循环使用7次后催化活性降低不明显.

Tetraalkylammonium Stabilized Palladium Chloride as a High Efficient Reusable Catalyst for the Biginelli Reaction

An improved one pot procedure, which condenses an aldehyde, α,β ketoester and urea or thiourea to yield 3,4 dihydropyrimidin 2 (1H) ones/thiones, has been developed by using tetraalkylammonium stabilized palladium chloride as the catalyst. Experimental results showed that the methodology revealed high catalytic activity for the synthesis of Biginelli reaction products. In this paper, we utilized palladium chloride quaternary ammonium salt (PdCl_2/BTEACl) as a low catalytic loading, homogeneous, neutral, efficient and reusable catalytic system for the Biginelli reaction. This approach appears to be a mild, simple, practical and reusable green process for the preparation of Biginelli products. The catalytic system can be easily separated, and reused for seven times without a considerable change in its activity detected by HPLC.