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
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
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
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.
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
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
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...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
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.
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.
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.
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.
