Stereoselective synthesis of multi-substituted cyclobutanes with different substituents is still a daunting challenge in organic synthesis.We report here a practical and facile approach to synthesizing all-trans 2,3,4...Stereoselective synthesis of multi-substituted cyclobutanes with different substituents is still a daunting challenge in organic synthesis.We report here a practical and facile approach to synthesizing all-trans 2,3,4-trisubstituted cyclobutanones from readily available dichlorocyclobutanones.The substitution reaction proceeds smoothly via oxyallyl cation intermediates under mild basic conditions.Further transformation to the synthesis of 1,2,3,4-tetrasubstituted cyclobutanes was also explored.展开更多
Herein,we report an efficient and practical protocol for the photoinduced dehalocyclization of ortho-halophenylacrylamides with formate by the engagement of a CO_(2) radical anion to access substituted oxindoles.This ...Herein,we report an efficient and practical protocol for the photoinduced dehalocyclization of ortho-halophenylacrylamides with formate by the engagement of a CO_(2) radical anion to access substituted oxindoles.This method proceeds smoothly under mild conditions and exhibits a wide range of substrate as well as remarkable functional group compatibility.展开更多
Comprehensive Summary The radical-mediated reductive functionalization of aryl halides has been extensively studied.However,the related radical-mediated intermolecular reductive 1,2-diarylation of alkenes,using aryl h...Comprehensive Summary The radical-mediated reductive functionalization of aryl halides has been extensively studied.However,the related radical-mediated intermolecular reductive 1,2-diarylation of alkenes,using aryl halides as aryl radical sources,remains unexplored.Herein,a new electrophotocatalytic intermolecular reductive 1,2-diarylation of alkenes is reported using aryl halides and cyanoaromatics to produce polyarylated alkanes.Using synergistic cathodic reduction and visible-light photoredox catalysis,various electron-rich and electron-deficient aryl halides are combined with various alkenes and cyanoaromatics to characterize the broad substrate scope,excellent functional group compatibility,and excellent selectivity of this reaction.Mechanistic investigations reveal that this reaction may proceed via a radical process initiated by the reductive generation of aryl radicals from aryl halides and terminated by radical-radical coupling with cyanoaromatic radical anions.展开更多
A new electrochemical strategy for the atom transfer radical addition(ATRA)of polychloroalkanes across olefins has been realized by the synergism of paired electrolysis and halogen bonding activation.Notably,readily a...A new electrochemical strategy for the atom transfer radical addition(ATRA)of polychloroalkanes across olefins has been realized by the synergism of paired electrolysis and halogen bonding activation.Notably,readily accessible 4,4-di-tert-butyl bipyridine(dtbpy),acting as a halogen bonding acceptor,shifted the reduction potential of C—Cl bonds positively by 110 mV.The decreased operating potential leads to a wide substrate scope and excellent functional group compatibility.A diverse array of terminal and internal alkenes such as(hetero)aryl olefins,unactive aliphatic olefins,and natural products and drugs-derived olefins were well compatible.展开更多
A deuterated methylthiolating reagent with a broad spectrum,designated as DMTp,has been ingeniously formulated.This new reagent can be produced with high efficiency through the simple combination of commercially avail...A deuterated methylthiolating reagent with a broad spectrum,designated as DMTp,has been ingeniously formulated.This new reagent can be produced with high efficiency through the simple combination of commercially available methyl 3-thiopropanoate and CD_(3)l.This novel SCD_(3) reagent exhibits excellent reactivity with electrophiles such as alkyl iodides,benzyl chlorides,aryl halides(l,Br)and aryl triflates,resulting in high levels of deuterium content(99%D).Representative deuterated methylthiolated biomolecules,such as Sulfoxaflor,havebeen synthesizedforuse in pharmaceutical discoveryand development.展开更多
This study involved an evaluation of the potential for bioremediation of polychlorinated biphenyls(PCBs) in the effluent from a large municipal wastewater treatment plant. It was focused on the presence of PCBs in two...This study involved an evaluation of the potential for bioremediation of polychlorinated biphenyls(PCBs) in the effluent from a large municipal wastewater treatment plant. It was focused on the presence of PCBs in two types of effluents: the continuous effluent present during dry weather conditions and the intermittently present effluent that was present during wet weather due to incoming stormwater. The annual discharge of PCBs for both types of effluent was calculated based on a five-year dataset(2011–2015). In addition, the toxicity and bioremediation potential of the PCBs in the effluent were also assessed. It was found that the continuous effluent was responsible for the majority of the discharged PCB into the receiving river(1821 g for five years), while the intermittent effluent contributed 260 g over the five years.The average number of chlorine per biphenyl for the detected PCB congeners showed a 19%difference between the two types of effluent, which indicated a potential for organohalide respiration of PCBs during the continuous treatment. This was further supported by a high level of tri-, tetra-and penta-chlorinated congeners accounting for 75% of the anaerobically respired PCBs. Potential for aerobic degradation and thus biomineralization of PCBs was identified for both effluents. Furthermore, toxicity of 12 dioxin-like PCBs showed that normal operation of the wastewater reduced the toxicity throughout the wastewater treatment plant.展开更多
Due to the toxicity of bioaccumulative organohalides to human beings and ecosystems,a variety of biotic and abiotic remediation methods have been developed to remove organohalides from contaminated environments.Biorem...Due to the toxicity of bioaccumulative organohalides to human beings and ecosystems,a variety of biotic and abiotic remediation methods have been developed to remove organohalides from contaminated environments.Bioremediation employing organohalide-respiring bacteria(OHRB)-mediated microbial reductive dehalogenation(Bio-RD)represents a cost-effective and environmentally friendly approach to attenuate highly-halogenated organohalides,specifically organohalides in soil,sediment and other anoxic environments.Nonetheless,many factors severely restrict the implications of OHRB-based bioremediation,including incomplete dehalogenation,low abundance of OHRB and consequent low dechlorination activity.Recently,the development of in situ chemical oxidation(ISCO)based on sulfate radicals(SO_(4)^(·−))via the persulfate activation and oxidation(PAO)process has attracted tremendous research interest for the remediation of lowly-halogenated organohalides due to its following advantages,e.g.,complete attenuation,high reactivity and no selectivity to organohalides.Therefore,integration of OHRB-mediated Bio-RD and subsequent PAO(Bio-RD-PAO)may provide a promising solution to the remediation of organohalides.In this review,we first provide an overview of current progress in Bio-RD and PAO and compare their limitations and advantages.We then critically discuss the integration of Bio-RD and PAO(Bio-RD-PAO)for complete attenuation of organohalides and its prospects for future remediation applications.Overall,Bio-RD-PAO opens up opportunities for complete attenuation and consequent effective in situ remediation of persistent organohalide pollution.展开更多
基金supported by the National Natural Science Foundation of China(22071028,21921003).
文摘Stereoselective synthesis of multi-substituted cyclobutanes with different substituents is still a daunting challenge in organic synthesis.We report here a practical and facile approach to synthesizing all-trans 2,3,4-trisubstituted cyclobutanones from readily available dichlorocyclobutanones.The substitution reaction proceeds smoothly via oxyallyl cation intermediates under mild basic conditions.Further transformation to the synthesis of 1,2,3,4-tetrasubstituted cyclobutanes was also explored.
基金supported by the National Natural Science Foundation of China(No.22293011).
文摘Herein,we report an efficient and practical protocol for the photoinduced dehalocyclization of ortho-halophenylacrylamides with formate by the engagement of a CO_(2) radical anion to access substituted oxindoles.This method proceeds smoothly under mild conditions and exhibits a wide range of substrate as well as remarkable functional group compatibility.
基金the National Natural Science Foundation of China(Nos.21871126 and 22271245)the Jiangxi Province Science and Technology Project(Nos.20212AEi91002 and 20224BAB213013)+1 种基金the Jiangxi Educational Committee Foundation of China(GJJ210906)the Open Research Fund of the School of Chemistry and Chemical Engineering,Henan Normal University(No.2021zD01)for theirfinancial support.
文摘Comprehensive Summary The radical-mediated reductive functionalization of aryl halides has been extensively studied.However,the related radical-mediated intermolecular reductive 1,2-diarylation of alkenes,using aryl halides as aryl radical sources,remains unexplored.Herein,a new electrophotocatalytic intermolecular reductive 1,2-diarylation of alkenes is reported using aryl halides and cyanoaromatics to produce polyarylated alkanes.Using synergistic cathodic reduction and visible-light photoredox catalysis,various electron-rich and electron-deficient aryl halides are combined with various alkenes and cyanoaromatics to characterize the broad substrate scope,excellent functional group compatibility,and excellent selectivity of this reaction.Mechanistic investigations reveal that this reaction may proceed via a radical process initiated by the reductive generation of aryl radicals from aryl halides and terminated by radical-radical coupling with cyanoaromatic radical anions.
基金the National Natural Science Foundation of China(21871019,21901263,22171015)Beijing Municipal Education Committee Project(KZ202110005003,KM202110005006)Beijing Natural Science Foundation(2222003).
文摘A new electrochemical strategy for the atom transfer radical addition(ATRA)of polychloroalkanes across olefins has been realized by the synergism of paired electrolysis and halogen bonding activation.Notably,readily accessible 4,4-di-tert-butyl bipyridine(dtbpy),acting as a halogen bonding acceptor,shifted the reduction potential of C—Cl bonds positively by 110 mV.The decreased operating potential leads to a wide substrate scope and excellent functional group compatibility.A diverse array of terminal and internal alkenes such as(hetero)aryl olefins,unactive aliphatic olefins,and natural products and drugs-derived olefins were well compatible.
基金financial support from the National Natural Science Foundation of China(22101005)the National Key Research and Development Program of China(2021YFD1700104)+1 种基金Key R&D Projects of Anhui Province(202104a06020008)Excellent Youth Program of Anhui Province(2022AH030095).
文摘A deuterated methylthiolating reagent with a broad spectrum,designated as DMTp,has been ingeniously formulated.This new reagent can be produced with high efficiency through the simple combination of commercially available methyl 3-thiopropanoate and CD_(3)l.This novel SCD_(3) reagent exhibits excellent reactivity with electrophiles such as alkyl iodides,benzyl chlorides,aryl halides(l,Br)and aryl triflates,resulting in high levels of deuterium content(99%D).Representative deuterated methylthiolated biomolecules,such as Sulfoxaflor,havebeen synthesizedforuse in pharmaceutical discoveryand development.
基金supported by the University of Maryland, Clark School of Engineering
文摘This study involved an evaluation of the potential for bioremediation of polychlorinated biphenyls(PCBs) in the effluent from a large municipal wastewater treatment plant. It was focused on the presence of PCBs in two types of effluents: the continuous effluent present during dry weather conditions and the intermittently present effluent that was present during wet weather due to incoming stormwater. The annual discharge of PCBs for both types of effluent was calculated based on a five-year dataset(2011–2015). In addition, the toxicity and bioremediation potential of the PCBs in the effluent were also assessed. It was found that the continuous effluent was responsible for the majority of the discharged PCB into the receiving river(1821 g for five years), while the intermittent effluent contributed 260 g over the five years.The average number of chlorine per biphenyl for the detected PCB congeners showed a 19%difference between the two types of effluent, which indicated a potential for organohalide respiration of PCBs during the continuous treatment. This was further supported by a high level of tri-, tetra-and penta-chlorinated congeners accounting for 75% of the anaerobically respired PCBs. Potential for aerobic degradation and thus biomineralization of PCBs was identified for both effluents. Furthermore, toxicity of 12 dioxin-like PCBs showed that normal operation of the wastewater reduced the toxicity throughout the wastewater treatment plant.
基金This study was supported by the National Natural Science Foundation of China(Grant Nos.41922049 and 41877111)the Fundamental Research Funds for the Central Universities(No.19lgzd30)the Guangzhou Science and Technology Program general project(No.201804010141).
文摘Due to the toxicity of bioaccumulative organohalides to human beings and ecosystems,a variety of biotic and abiotic remediation methods have been developed to remove organohalides from contaminated environments.Bioremediation employing organohalide-respiring bacteria(OHRB)-mediated microbial reductive dehalogenation(Bio-RD)represents a cost-effective and environmentally friendly approach to attenuate highly-halogenated organohalides,specifically organohalides in soil,sediment and other anoxic environments.Nonetheless,many factors severely restrict the implications of OHRB-based bioremediation,including incomplete dehalogenation,low abundance of OHRB and consequent low dechlorination activity.Recently,the development of in situ chemical oxidation(ISCO)based on sulfate radicals(SO_(4)^(·−))via the persulfate activation and oxidation(PAO)process has attracted tremendous research interest for the remediation of lowly-halogenated organohalides due to its following advantages,e.g.,complete attenuation,high reactivity and no selectivity to organohalides.Therefore,integration of OHRB-mediated Bio-RD and subsequent PAO(Bio-RD-PAO)may provide a promising solution to the remediation of organohalides.In this review,we first provide an overview of current progress in Bio-RD and PAO and compare their limitations and advantages.We then critically discuss the integration of Bio-RD and PAO(Bio-RD-PAO)for complete attenuation of organohalides and its prospects for future remediation applications.Overall,Bio-RD-PAO opens up opportunities for complete attenuation and consequent effective in situ remediation of persistent organohalide pollution.
