Over the past decade many bifunctional amine-thioureas have been developed as active metal-free organocatalysts. Coopera-tive catalysis of these amino-thioureas allows high reaction rates and excellent transfer of ste...Over the past decade many bifunctional amine-thioureas have been developed as active metal-free organocatalysts. Coopera-tive catalysis of these amino-thioureas allows high reaction rates and excellent transfer of stereocbemical information. Despite these impressive advances, the design of new high-performance catalysts for applications in asymmetric catalytic reactions is of ongoing interest in organic chemistry. Herein we describe a cooperative catalyst system consisting of a chiral amine thiourea and an achiral organic acid that promotes the conjugate addition of 4-nonsubstituted pyrazolones to nitroolefins and subsequent dearomative chlorination. The corresponding adducts and the subsequent products were obtained in high to excel lent yields （up to 99%） and high stereoselectivities （up to 99/1 dr, 98% ee） under mild reacton conditions. These transforma tions provide an easy access to enantio-enriched pvrazole derivatives, which could possess Potential oharmaceutical activity.展开更多
设计合成了一种新型叔胺方酰胺型有机催化剂,并将其应用于乙酰丙酮与硝基烯烃的不对称Michael加成反应。在无溶剂条件下,催化剂使用量为0.5 mol%时,催化体系表现出良好的活性和立体选择性,得到了一系列用于合成和医药的重要手性化合物,...设计合成了一种新型叔胺方酰胺型有机催化剂,并将其应用于乙酰丙酮与硝基烯烃的不对称Michael加成反应。在无溶剂条件下,催化剂使用量为0.5 mol%时,催化体系表现出良好的活性和立体选择性,得到了一系列用于合成和医药的重要手性化合物,收率最高95%,对映选择性最高97% ee 。展开更多
基金supported by the National Natural Science Foundation of China(21172170 and 21225208)the National Basic Research Program of China(973 Program,2014CB745100)
文摘Over the past decade many bifunctional amine-thioureas have been developed as active metal-free organocatalysts. Coopera-tive catalysis of these amino-thioureas allows high reaction rates and excellent transfer of stereocbemical information. Despite these impressive advances, the design of new high-performance catalysts for applications in asymmetric catalytic reactions is of ongoing interest in organic chemistry. Herein we describe a cooperative catalyst system consisting of a chiral amine thiourea and an achiral organic acid that promotes the conjugate addition of 4-nonsubstituted pyrazolones to nitroolefins and subsequent dearomative chlorination. The corresponding adducts and the subsequent products were obtained in high to excel lent yields （up to 99%） and high stereoselectivities （up to 99/1 dr, 98% ee） under mild reacton conditions. These transforma tions provide an easy access to enantio-enriched pvrazole derivatives, which could possess Potential oharmaceutical activity.
