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
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.
