铜催化不对称合成螺环吡唑啉酮的反应因素评价研究

Evaluation of Reaction Factors for Copper-catalyzed Asymmetric Synthesis of Spiropyrazolones

利用炔系硝基烯烃和吡唑酮的迈克尔加成/Conia-ene环化反应立体选择性合成手性螺环吡唑啉酮,并对影响反应的因素进行考察,比较了过渡金属、不同骨架的配体、溶剂、温度对反应的影响.结果表明,当以金鸡纳碱和廉价金属铜为催化剂,三氯甲烷为溶剂在-40℃下,反应可以达到97%的产率、大于20:1的dr值和91%的ee值.

Chiral spirocyclic pyrazolone was stereoselectively synthesized by Michael addition/Conia-ene cyclization reaction between alkynyl nitroolefins and pyrazolone,and the factors affecting the reaction were investigated.The effects of transition metals,ligands with different frameworks,solvents,and temperature on the reaction were compared.The results showed that when cinchona alkaloids and copper were used as catalysts and chloroform was used as solvent at-40℃,the yield,dr value and ee value of reaction could reach 97%,greater than 20∶1and 91%,respectively.