Tetrazole-l-acetic acid was found to serve as a superior ligand for Cul-catalyzed N-arylation of imidazoles with aryl iodides under a low catalyst loading （5 mol% of Cul）. A variety of aryl iodides could he aminated...Tetrazole-l-acetic acid was found to serve as a superior ligand for Cul-catalyzed N-arylation of imidazoles with aryl iodides under a low catalyst loading （5 mol% of Cul）. A variety of aryl iodides could he aminated to provide the N-arylated products in good to excellent yields without the need of an inert atmosphere.展开更多
An operationally simple and inexpensive catalyst system was developed for the cross coupling of potassium thiocyanate with aryl iodides by using CuI as catalyst, 1, 10-phenanthroline as ligand, and tetraethylammonium ...An operationally simple and inexpensive catalyst system was developed for the cross coupling of potassium thiocyanate with aryl iodides by using CuI as catalyst, 1, 10-phenanthroline as ligand, and tetraethylammonium iodide as activator. The procedure is applicable for the synthesis of diverse aryl thiocyanates without any exotic, poisonous reagents.展开更多
A new copper and silver-mediated cyanation of aryl iodides with DDQ as a cyanide source is achieved, provid- ing nitriles with good yields. This new approach represents a safe method leading to aryl nitriles.
Homocoupling of aryl iodides catalyzed by cyclopalladated complexes of tertiary arylamines gives symmetric biaryls with good yields in DMA or ionic liquid [Bmim]BF4. This catalytic alternative of the Ullmann reaction ...Homocoupling of aryl iodides catalyzed by cyclopalladated complexes of tertiary arylamines gives symmetric biaryls with good yields in DMA or ionic liquid [Bmim]BF4. This catalytic alternative of the Ullmann reaction has proved to be sensitive to both electronic and steric factors of substrates.展开更多
Metathesis reactions represent powerful synthetic tools that have been used in a number of fields from the synthesis of natural product to functional material preparation.However,the C-H metathesis reaction is extreme...Metathesis reactions represent powerful synthetic tools that have been used in a number of fields from the synthesis of natural product to functional material preparation.However,the C-H metathesis reaction is extremely rare.Herein,we report the first Pd(Ⅱ)-catalyzed C-H iodination of arenes using 2-nitrophenyl iodides as the mild iodinating reagents via a formal metathesis reaction.Unusual C-I bond formation occurred with aryl iodides in preference to competing C-C coupling in this reaction.Assisted by aliphatic carboxyl directing groups,a range of hydrocinnamic acids and related arenes could be selectively iodinated at either meta-or orthopositions of the phenyl ring.Remote diastereoselective C-H activation was also promising.This method might unfold a novel approach to iodinate challenging substrates.展开更多
We herein present an efficient denitrative iodination method of(hetero)nitroarenes mediated by commercially available and cost-effective hydroiodic acid(HI).During the reaction process,HI plays its dual roles as both ...We herein present an efficient denitrative iodination method of(hetero)nitroarenes mediated by commercially available and cost-effective hydroiodic acid(HI).During the reaction process,HI plays its dual roles as both the sustainable reductant of nitro group and iodine source in the iodination step,which successfully integrates three steps into a one-pot procedure and significantly simplifies the reaction system.This approach enables a smooth metal-free conversion of nitroarenes to corresponding aryl iodides via one-pot process,exhibits a broad substrate scope and good reaction efficiency,and was conveniently applied in the concise synthesis of pharmaceuticals.展开更多
The valorization of nitrous oxide(N_(2)O)as an oxygen atom donor presents an attractive opportunity for green chemistry applications,leveraging both its industrial abundance and thermodynamically favorable oxidation p...The valorization of nitrous oxide(N_(2)O)as an oxygen atom donor presents an attractive opportunity for green chemistry applications,leveraging both its industrial abundance and thermodynamically favorable oxidation potential.However,practical implementation has been constrained by the inherent kinetic inertness and poor coordinating ability of N_(2)O.While prior studies achieved N_(2)O-mediated conversion of aryl halides to phenols,such transformations necessitated stoichiometric chemical reductants and elevated pressure(2 atm),posing challenges in operational safety and process scalability.This study focuses on an electrochemical strategy that enables efficient oxygen atom transfer under ambient pressure through controlled current application.This methodology facilitates the selective transformation of aryl iodides to phenols without external reducing agents,establishing an environmentally benign synthetic pathway.By replacing traditional chemical reductants with electrons as the sole reducing equivalent,our approach addresses critical sustainability challenges in aromatic oxygenation chemistry while maintaining operational simplicity under mild conditions.展开更多
Although practical catalytic transformations involving aryl chlorides are diffcult to implement,they are highly desirable since the starting compounds are inexpensive and readily available.Retarded oxidative addition ...Although practical catalytic transformations involving aryl chlorides are diffcult to implement,they are highly desirable since the starting compounds are inexpensive and readily available.Retarded oxidative addition of aryl chlorides to palladium catalyst as compared to aryl bromides and aryl iodides is typically taken for granted as an explanation for the overall ineffciency of the process.The comparative experi mental study and analysis reported herein suggest that oxidative addition cannot be considered the sole reason of the observed low reactivity of aryl chlorides.Other factors were found to play an important role in influencing the reactivity of aryl halides.The presentfindings suggest that a substantial revision of cata lyst design principles is necessary for successful transformations of aryl chlorides.展开更多
The synthesis of aryl iodides from commercially available raw chemicals by simple,cheap and green strategies is of fundamental signifi cance.Aryl iodides can undergo a series of homo-/cross-coupling reactions for the ...The synthesis of aryl iodides from commercially available raw chemicals by simple,cheap and green strategies is of fundamental signifi cance.Aryl iodides can undergo a series of homo-/cross-coupling reactions for the synthesis of important industrial chemicals and materials.Traditional methods require the electrophilic substitution on aromatic compounds by iodine or hypervalent iodine compounds,which suff ers from the use of erosive halogens or hazardous oxidants.With the development of green chemistry in the fi eld of electrochemical synthesis,anodic oxidation-derived I^(+)cations have been used for substitution reactions.However,the selectivity of the iodination by these electrochemical methods remains unsatisfactory.We believed that the anolyte is contaminated by trace platinum species from the working electrode.Herein,we report the generation of active I^(+)species from the anodic oxidation of I_(2) in acetonitrile using a glassy carbon electrode.With the presence of H^(+),electrolyte prepared with a glassy carbon anode can react with anisole to selectively form 4-iodoanisole with a yield as high as 97%.On contrast,the electrolytes prepared from Pt and graphite anodes fi nished the reaction with yields of 16%and 60%for 4-iodoanisole,respectively.This electrochemical method also applies to the iodination of toluene,benzonitrile and bromobenzene,delivering the target para-iodination products with 92%,84%,and 73%yields,respectively.Thus,an atom-effi cient and highly selective aryl iodination method was developed without the use of excessive oxidants.展开更多
This work describes the efficacy of[PNP]PdCl(1a),where[PNP]^(-)=bis(2-diphenylphosphinophenyl)amide,as a catalyst precursor for C_(sp)-C_(sp2) bond-forming cross-coupling reactions of terminal alkynes with aryl halide...This work describes the efficacy of[PNP]PdCl(1a),where[PNP]^(-)=bis(2-diphenylphosphinophenyl)amide,as a catalyst precursor for C_(sp)-C_(sp2) bond-forming cross-coupling reactions of terminal alkynes with aryl halides in the presence of copper bromide and aliphatic amines in ethereal solutions under mild conditions.This catalysis is compatible with acetylenes that are alkyl,alkenyl,(hetero)aryl,or silyl substituted and aryl iodides or bromides that are electronically activated,neutral,or deactivated.The low reaction constants of 0.82(6)and 0.97(7)obtained from Hammett plots of competitive reactions employing electronically distinct aryl iodides and terminal alkynes,respectively,are likely suggestive of irrelevance of the rate-determining step in these catalytic transformations to oxidative addition of aryl halides or generation of mono-substituted acetylides.In sharp contrast,reactions employing a phosphorus-bound isopropyl derived 1b gave rather unsatisfactory results,highlighting a profound phosphorus substituent effect on this aryl alkynylation catalysis.展开更多
Two general protocols have been developed for the photoinduced,metal-free direct arylation of unactivated arenes with aryl iodide.Both methods gave good to excellent yields for most substrates.Notably,the C-F bond in ...Two general protocols have been developed for the photoinduced,metal-free direct arylation of unactivated arenes with aryl iodide.Both methods gave good to excellent yields for most substrates.Notably,the C-F bond in method A and the C-F,C-C1 and C-Br bonds in method B could survive the arylation reaction.These methods offered excellent options for syntheses of biaryls.展开更多
基金supported fnancially by the National Basic Research Program of China(973 Program,No.2012CB722603)the Start-Up Foundation for Young Scientists of Shihezi University(Nos.RCZX201012,RCZX201014,RCZX201015)
文摘Tetrazole-l-acetic acid was found to serve as a superior ligand for Cul-catalyzed N-arylation of imidazoles with aryl iodides under a low catalyst loading （5 mol% of Cul）. A variety of aryl iodides could he aminated to provide the N-arylated products in good to excellent yields without the need of an inert atmosphere.
文摘An operationally simple and inexpensive catalyst system was developed for the cross coupling of potassium thiocyanate with aryl iodides by using CuI as catalyst, 1, 10-phenanthroline as ligand, and tetraethylammonium iodide as activator. The procedure is applicable for the synthesis of diverse aryl thiocyanates without any exotic, poisonous reagents.
基金We thank the National Natural Science Foundation of China （No. 21272178）, the Natural Science Founda- tion of Zhejiang Province （Nos. R4110294 and LY12B02010）.
文摘A new copper and silver-mediated cyanation of aryl iodides with DDQ as a cyanide source is achieved, provid- ing nitriles with good yields. This new approach represents a safe method leading to aryl nitriles.
基金Project supported by the National Natural Science Foundation of China (No. 20172016) and Shanghai Phosphor Project of Science & Technology for Excellent Young Research (Nos. 01QA14017 and 02QA14016).
文摘Homocoupling of aryl iodides catalyzed by cyclopalladated complexes of tertiary arylamines gives symmetric biaryls with good yields in DMA or ionic liquid [Bmim]BF4. This catalytic alternative of the Ullmann reaction has proved to be sensitive to both electronic and steric factors of substrates.
基金NSFC(grant nos.22022111 and 22071248)the Natural Science Foundation of Fujian Province(grant nos.2020J02008 and 2020J01108)+1 种基金the Youth Innovation Promotion Association of the Chinese Academy of Sciences(grant no.2020306)the Strategic Priority Research Program of the Chinese Academy of Sciences(grant no.XDB20000000).
文摘Metathesis reactions represent powerful synthetic tools that have been used in a number of fields from the synthesis of natural product to functional material preparation.However,the C-H metathesis reaction is extremely rare.Herein,we report the first Pd(Ⅱ)-catalyzed C-H iodination of arenes using 2-nitrophenyl iodides as the mild iodinating reagents via a formal metathesis reaction.Unusual C-I bond formation occurred with aryl iodides in preference to competing C-C coupling in this reaction.Assisted by aliphatic carboxyl directing groups,a range of hydrocinnamic acids and related arenes could be selectively iodinated at either meta-or orthopositions of the phenyl ring.Remote diastereoselective C-H activation was also promising.This method might unfold a novel approach to iodinate challenging substrates.
基金the National Key Research and Development Project(No.2023YFF1205103)the National Natural Science Foundation of China(No.22371007)the Peking University Medicine plus X Pilot Program-Key Technologies R&D Project(No.2024YXXLHGG001)for financial support。
文摘We herein present an efficient denitrative iodination method of(hetero)nitroarenes mediated by commercially available and cost-effective hydroiodic acid(HI).During the reaction process,HI plays its dual roles as both the sustainable reductant of nitro group and iodine source in the iodination step,which successfully integrates three steps into a one-pot procedure and significantly simplifies the reaction system.This approach enables a smooth metal-free conversion of nitroarenes to corresponding aryl iodides via one-pot process,exhibits a broad substrate scope and good reaction efficiency,and was conveniently applied in the concise synthesis of pharmaceuticals.
基金National Natural Science Foundation of China(Project No.:52320105003,Project No.:52303019)the CAS-ANSO Co-funding Research Project(Project No.:CAS-ANSO-CF-2024)+2 种基金the National Key R&D Program of China(Project No.:2023YFC3707201)the Fundamental Research Funds for the Central Universities(Project No.:E3ET1803)China Postdoctoral Science Foundation(Project No:2024T170904)。
文摘The valorization of nitrous oxide(N_(2)O)as an oxygen atom donor presents an attractive opportunity for green chemistry applications,leveraging both its industrial abundance and thermodynamically favorable oxidation potential.However,practical implementation has been constrained by the inherent kinetic inertness and poor coordinating ability of N_(2)O.While prior studies achieved N_(2)O-mediated conversion of aryl halides to phenols,such transformations necessitated stoichiometric chemical reductants and elevated pressure(2 atm),posing challenges in operational safety and process scalability.This study focuses on an electrochemical strategy that enables efficient oxygen atom transfer under ambient pressure through controlled current application.This methodology facilitates the selective transformation of aryl iodides to phenols without external reducing agents,establishing an environmentally benign synthetic pathway.By replacing traditional chemical reductants with electrons as the sole reducing equivalent,our approach addresses critical sustainability challenges in aromatic oxygenation chemistry while maintaining operational simplicity under mild conditions.
基金funded by RFBR according to the research project no.19-33-50030.
文摘Although practical catalytic transformations involving aryl chlorides are diffcult to implement,they are highly desirable since the starting compounds are inexpensive and readily available.Retarded oxidative addition of aryl chlorides to palladium catalyst as compared to aryl bromides and aryl iodides is typically taken for granted as an explanation for the overall ineffciency of the process.The comparative experi mental study and analysis reported herein suggest that oxidative addition cannot be considered the sole reason of the observed low reactivity of aryl chlorides.Other factors were found to play an important role in influencing the reactivity of aryl halides.The presentfindings suggest that a substantial revision of cata lyst design principles is necessary for successful transformations of aryl chlorides.
文摘The synthesis of aryl iodides from commercially available raw chemicals by simple,cheap and green strategies is of fundamental signifi cance.Aryl iodides can undergo a series of homo-/cross-coupling reactions for the synthesis of important industrial chemicals and materials.Traditional methods require the electrophilic substitution on aromatic compounds by iodine or hypervalent iodine compounds,which suff ers from the use of erosive halogens or hazardous oxidants.With the development of green chemistry in the fi eld of electrochemical synthesis,anodic oxidation-derived I^(+)cations have been used for substitution reactions.However,the selectivity of the iodination by these electrochemical methods remains unsatisfactory.We believed that the anolyte is contaminated by trace platinum species from the working electrode.Herein,we report the generation of active I^(+)species from the anodic oxidation of I_(2) in acetonitrile using a glassy carbon electrode.With the presence of H^(+),electrolyte prepared with a glassy carbon anode can react with anisole to selectively form 4-iodoanisole with a yield as high as 97%.On contrast,the electrolytes prepared from Pt and graphite anodes fi nished the reaction with yields of 16%and 60%for 4-iodoanisole,respectively.This electrochemical method also applies to the iodination of toluene,benzonitrile and bromobenzene,delivering the target para-iodination products with 92%,84%,and 73%yields,respectively.Thus,an atom-effi cient and highly selective aryl iodination method was developed without the use of excessive oxidants.
文摘This work describes the efficacy of[PNP]PdCl(1a),where[PNP]^(-)=bis(2-diphenylphosphinophenyl)amide,as a catalyst precursor for C_(sp)-C_(sp2) bond-forming cross-coupling reactions of terminal alkynes with aryl halides in the presence of copper bromide and aliphatic amines in ethereal solutions under mild conditions.This catalysis is compatible with acetylenes that are alkyl,alkenyl,(hetero)aryl,or silyl substituted and aryl iodides or bromides that are electronically activated,neutral,or deactivated.The low reaction constants of 0.82(6)and 0.97(7)obtained from Hammett plots of competitive reactions employing electronically distinct aryl iodides and terminal alkynes,respectively,are likely suggestive of irrelevance of the rate-determining step in these catalytic transformations to oxidative addition of aryl halides or generation of mono-substituted acetylides.In sharp contrast,reactions employing a phosphorus-bound isopropyl derived 1b gave rather unsatisfactory results,highlighting a profound phosphorus substituent effect on this aryl alkynylation catalysis.
基金financially supported by the National Basic Research Program of China(2011CB932404,2011CBA00501)the National Natural Science Foundation of China(21332001,21431008,21301173)
文摘Two general protocols have been developed for the photoinduced,metal-free direct arylation of unactivated arenes with aryl iodide.Both methods gave good to excellent yields for most substrates.Notably,the C-F bond in method A and the C-F,C-C1 and C-Br bonds in method B could survive the arylation reaction.These methods offered excellent options for syntheses of biaryls.
