A new enone (CH 3CO C( p NO 2C 6H 4COO)=CH S C 6H 4( p Br) 5, C 17 H 12 NBrO 5S, M r =422.25) was synthesized and its crystal structure was determined by X ray diffraction method. The crystal belongs to the monoclinic...A new enone (CH 3CO C( p NO 2C 6H 4COO)=CH S C 6H 4( p Br) 5, C 17 H 12 NBrO 5S, M r =422.25) was synthesized and its crystal structure was determined by X ray diffraction method. The crystal belongs to the monoclinic system, space group P2 1/c with a=6.4121(9), b=12.804(1), c=20.998(2) , β=94.884(9)°, V=1717.1(3) 3, Z=4, D c =1.633 g/cm 3, μ (Mo Kα )=2.542 mm -1 , F( 000)=848. Final R =0.0428 and wR =0.0916 for 3335 reflections with I>2σ(I) . The title compound exists as Z isomer with p bromothiophenolate and o nitrobenzoate groups cis arranged around asymmetrical centre. This observation suggests that the substitution of thiophenolate for bromine is a stereoselective step.展开更多
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
文摘A new enone (CH 3CO C( p NO 2C 6H 4COO)=CH S C 6H 4( p Br) 5, C 17 H 12 NBrO 5S, M r =422.25) was synthesized and its crystal structure was determined by X ray diffraction method. The crystal belongs to the monoclinic system, space group P2 1/c with a=6.4121(9), b=12.804(1), c=20.998(2) , β=94.884(9)°, V=1717.1(3) 3, Z=4, D c =1.633 g/cm 3, μ (Mo Kα )=2.542 mm -1 , F( 000)=848. Final R =0.0428 and wR =0.0916 for 3335 reflections with I>2σ(I) . The title compound exists as Z isomer with p bromothiophenolate and o nitrobenzoate groups cis arranged around asymmetrical centre. This observation suggests that the substitution of thiophenolate for bromine is a stereoselective step.
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.
