Umpolung reactions of C=X bonds(X=O,N)are valuable ways of constructing new C–C bonds,which are sometimes difficult to be constructed using traditional synthetic pathways.Classical polarity inversion of C=X bonds(X=O...Umpolung reactions of C=X bonds(X=O,N)are valuable ways of constructing new C–C bonds,which are sometimes difficult to be constructed using traditional synthetic pathways.Classical polarity inversion of C=X bonds(X=O,N)usually requires air or moisture‐sensitive and strong reducing agents,which limit the feasibility of substrate scope.Herein we describe a photo‐induced reductive cross‐coupling reaction of aldehydes,ketones and imines with electron‐deficient arenes(aromatic nitriles)using fac‐Ir(ppy)3as a photocatalyst and diisopropylethylamine(DIPEA)as a terminal reductant under visible light irradiation.Mild conditions and high yields mean that this new polarity inversion strategy can be used with aryl‐substituted alcohols and amines.Spectroscopic studies and control experiments have demonstrated the oxidative quenching of Ir(ppy)3*by electron‐deficient arenes involved in the key step for the C–C bond formation.展开更多
目的探讨术后6个月内肺癌根治术后患者自我管理效能感与运动依从性的变化趋势,并分析二者间的预测关系,为改善术后患者运动依从性提供参考。方法采用便利抽样法,选取2022年12月至2023年5月南充市2所三级甲等综合医院胸外科首次行肺癌根...目的探讨术后6个月内肺癌根治术后患者自我管理效能感与运动依从性的变化趋势,并分析二者间的预测关系,为改善术后患者运动依从性提供参考。方法采用便利抽样法,选取2022年12月至2023年5月南充市2所三级甲等综合医院胸外科首次行肺癌根治术的188例患者作为研究对象,采用中文版癌症自我管理效能感量表(Chinese-version strategies used by people to promote health,C-SUPPH)、运动依从性量表调查患者出院前1d(TI)与术后1个月(T2)、3个月(T3)、6个月(T4)的自我管理效能感及运动依从性水平,构建交叉滞后模型分析自我管理效能感与运动依从性间的因果关系。结果178例患者完成研究;术后6个月内,肺癌根治术后患者自我管理效能感、运动依从性均呈先上升后下降趋势(均P<0.05);交叉滞后模型显示,术后早期(TI~T2)患者自我管理效能感与运动依从性互为因果(β=0.254,P=0.003;β=0.332,P=0.007);中期(T2~T3)患者自我管理效能感能正向预测运动依从性(β=0.286,P<0.001);后期(T3~T4)两者不能相互预测(均P>0.05)。结论肺癌根治术后患者自我管理效能感处于中等水平、运动依从性处于低水平;肺癌根治术后患者自我管理效能感、运动依从性的初始水平并不代表长期治疗后的变化趋势,两者间的预测关系也会发生改变。医护人员需考虑其动态变化特征和个体差异,在患者术后的各个阶段进行评估,及时给予针对性的干预。展开更多
A new cooperative nickel reductive catalysis and N,N-dimethylformamide-mediated strategy for umpolung C–S radical reductive cross coupling of S-(trifluoromethyl)arylsulfonothioates with alkyl halides to produce alkyl...A new cooperative nickel reductive catalysis and N,N-dimethylformamide-mediated strategy for umpolung C–S radical reductive cross coupling of S-(trifluoromethyl)arylsulfonothioates with alkyl halides to produce alkyl aryl thioethers is described. This reaction features excellent selectivity, wide functionality tolerance, broad substrate scope, and facile late-stage modification of biologically relevant molecules.Mechanistic studies recognize initial generation of an amidyl radical anion via thermoinduced reduction of DMF with Sn, followed by umpolung reduction and single electron transfer of the nucleophilic sulfonyl moiety to form a sulphydryl radical and engage the Ni^(0)/Ni^(Ⅰ)/Ni^(Ⅲ)/Ni^(I) catalytic cycle.展开更多
Two opposing explanations to significant rate retardation in dithioester-mediated polymerization with reversible addition fragmentation chain transfer process(RAFT),e.g: slow fragmentation of intermediate radicals (Mo...Two opposing explanations to significant rate retardation in dithioester-mediated polymerization with reversible addition fragmentation chain transfer process(RAFT),e.g: slow fragmentation of intermediate radicals (Model A),and cross termination between intermediates and growing radicals (Model B),had been proposed by Davis and Monteiro independently. In this paper,a comparison of simulation results of Model A and Model B with experiment results was presented. The simulated results show that the intermediate concentration of Model A is much higher than that of experiments,while Model B gives a rather high polymerization rate than experiments with large concentration of dithioesters. The reaction model was better fitted,in light of kinetics,intermediate concentration and distribution of molecular weight,to experimental data when both cross termination and slow fragmentation were taken into account. [WT5HZ]展开更多
文摘Umpolung reactions of C=X bonds(X=O,N)are valuable ways of constructing new C–C bonds,which are sometimes difficult to be constructed using traditional synthetic pathways.Classical polarity inversion of C=X bonds(X=O,N)usually requires air or moisture‐sensitive and strong reducing agents,which limit the feasibility of substrate scope.Herein we describe a photo‐induced reductive cross‐coupling reaction of aldehydes,ketones and imines with electron‐deficient arenes(aromatic nitriles)using fac‐Ir(ppy)3as a photocatalyst and diisopropylethylamine(DIPEA)as a terminal reductant under visible light irradiation.Mild conditions and high yields mean that this new polarity inversion strategy can be used with aryl‐substituted alcohols and amines.Spectroscopic studies and control experiments have demonstrated the oxidative quenching of Ir(ppy)3*by electron‐deficient arenes involved in the key step for the C–C bond formation.
文摘目的探讨术后6个月内肺癌根治术后患者自我管理效能感与运动依从性的变化趋势,并分析二者间的预测关系,为改善术后患者运动依从性提供参考。方法采用便利抽样法,选取2022年12月至2023年5月南充市2所三级甲等综合医院胸外科首次行肺癌根治术的188例患者作为研究对象,采用中文版癌症自我管理效能感量表(Chinese-version strategies used by people to promote health,C-SUPPH)、运动依从性量表调查患者出院前1d(TI)与术后1个月(T2)、3个月(T3)、6个月(T4)的自我管理效能感及运动依从性水平,构建交叉滞后模型分析自我管理效能感与运动依从性间的因果关系。结果178例患者完成研究;术后6个月内,肺癌根治术后患者自我管理效能感、运动依从性均呈先上升后下降趋势(均P<0.05);交叉滞后模型显示,术后早期(TI~T2)患者自我管理效能感与运动依从性互为因果(β=0.254,P=0.003;β=0.332,P=0.007);中期(T2~T3)患者自我管理效能感能正向预测运动依从性(β=0.286,P<0.001);后期(T3~T4)两者不能相互预测(均P>0.05)。结论肺癌根治术后患者自我管理效能感处于中等水平、运动依从性处于低水平;肺癌根治术后患者自我管理效能感、运动依从性的初始水平并不代表长期治疗后的变化趋势,两者间的预测关系也会发生改变。医护人员需考虑其动态变化特征和个体差异,在患者术后的各个阶段进行评估,及时给予针对性的干预。
基金the National Natural Science Foundation of China(No.22271245)the Jiangxi Province Science and Technology Project(Nos.20212AEI91002 and 20202ACBL213002)the Open Research Fund of School of Chemistry and Chemical Engineering,Henan Normal University(No.2021ZD01)for financial support.
文摘A new cooperative nickel reductive catalysis and N,N-dimethylformamide-mediated strategy for umpolung C–S radical reductive cross coupling of S-(trifluoromethyl)arylsulfonothioates with alkyl halides to produce alkyl aryl thioethers is described. This reaction features excellent selectivity, wide functionality tolerance, broad substrate scope, and facile late-stage modification of biologically relevant molecules.Mechanistic studies recognize initial generation of an amidyl radical anion via thermoinduced reduction of DMF with Sn, followed by umpolung reduction and single electron transfer of the nucleophilic sulfonyl moiety to form a sulphydryl radical and engage the Ni^(0)/Ni^(Ⅰ)/Ni^(Ⅲ)/Ni^(I) catalytic cycle.
文摘Two opposing explanations to significant rate retardation in dithioester-mediated polymerization with reversible addition fragmentation chain transfer process(RAFT),e.g: slow fragmentation of intermediate radicals (Model A),and cross termination between intermediates and growing radicals (Model B),had been proposed by Davis and Monteiro independently. In this paper,a comparison of simulation results of Model A and Model B with experiment results was presented. The simulated results show that the intermediate concentration of Model A is much higher than that of experiments,while Model B gives a rather high polymerization rate than experiments with large concentration of dithioesters. The reaction model was better fitted,in light of kinetics,intermediate concentration and distribution of molecular weight,to experimental data when both cross termination and slow fragmentation were taken into account. [WT5HZ]
