This paper presents a new synthetic route to hyperbranched polymer. An arylene bipropiolate monomer,dimethylmethylenebis(1,4-phenylene) bipropiolate,was prepared by a one-step esterification reaction of bisphenol A wi...This paper presents a new synthetic route to hyperbranched polymer. An arylene bipropiolate monomer,dimethylmethylenebis(1,4-phenylene) bipropiolate,was prepared by a one-step esterification reaction of bisphenol A with propiolic acid. Polycyclotrimrtization of the monomer was effected by reflux in dimethylformamide(DMF),producing a soluble hyperbranched poly(aroxycarbonylphenylene) in a good yield. The polymer was perfectly branched with a degree of branching of 100%.展开更多
Carbon dioxide was found as a selective agent to promote the palladium-catalyzed cyclotrimerization of alkynes in water. Both aryl and alkylacetylenes afforded the corresponding cyclotrimerization products regioselect...Carbon dioxide was found as a selective agent to promote the palladium-catalyzed cyclotrimerization of alkynes in water. Both aryl and alkylacetylenes afforded the corresponding cyclotrimerization products regioselectively in high yields using PdCl2, CuCl2, and CO2 as the catalytic system. However, tert-butylacetylene bearing a bulky group gave a dimerization product. Mechanism of this reaction was also discussed.展开更多
Aliphatic aldehydes such as ethanal, propanal, n-butanal, isobutyraldehyde, n-valeraldehyde, isovaleraldehyde, n-hexanal and n-octanal were converted into the corresponding 2.4,6-trialkyl-1,3,5-trioxanes through cyclo...Aliphatic aldehydes such as ethanal, propanal, n-butanal, isobutyraldehyde, n-valeraldehyde, isovaleraldehyde, n-hexanal and n-octanal were converted into the corresponding 2.4,6-trialkyl-1,3,5-trioxanes through cyclotrimerization in the presence of the ferric chloride based ionic liquids at room temperature without solvent in high selectivity. The effects of different ionic liquids, acidity of ionic liquids and temperature on cyclotrimerization were also studied. The results showed that the ferric chloride based ionic liquids （apparent molar fraction of FeCl3 （x（FeCl3）= 0.62）） were a kind of efficient catalysts for the cyclotrimerization of aliphatic aldehyde which could be separated conveniently from the reaction mixture and recycled without loss of catalytic activity. The conversion of isobutyraldehyde and the selectivity to 2,4,6-triisopropyl-1,3,5-trioxane were 91.1% and 99.8% respectively under optimum reaction condition （isobutyraldehyde 25.0 g, [Et3NH]Cl/FeCl3 （x（FeCl3）=0.62） 1.0 g, 25 ℃ for 1 h）.展开更多
The synthesis of 2, 4, 6-triisopropyl-1, 3, 5-trioxane with high yield and desirable selec- tivity from solvent-free cyclotrimerization of isobutyraldehyde catalyzed by ionic liquids was reported in this work.
The efficient synthesis of ultrathin crystalline twodimensional(2D)polymers with well-defined repeating units is essential to realize their broad applications but remains a great challenge.Herein,we report a new strat...The efficient synthesis of ultrathin crystalline twodimensional(2D)polymers with well-defined repeating units is essential to realize their broad applications but remains a great challenge.Herein,we report a new strategy to directly synthesize a series of few-layer 2D triazine-based polymers(2DTPs)via trimerization reaction of aromatic aldoximes in one step with a high yield of 85%using AlCl3 as catalyst under solvent-free conditions.The obtained 2D-TPs show high crystallinity,a lateral size of several micrometers,an ultrathin thickness less than 2 nm,and good dispersibility and processability.Through semi-in situ and detailed control experiments,we reveal that the 2D polymerization reaction is a two-step process of dehydration and then cyclotrimerization,and AlCl3 acts as not only catalyst but also an in situ generated template for promoting the formation of 2D-TPs.When explored as a new polymeric anode for potassium-ion batteries,the 2D-TP displayed an extraordinary reversible specific capacity of 356 mAh g^(−1)at 0.05 A g^(−1),which is among the best performances ever reported,outstanding rate capability(153 mAh g^(−1)at 1 A g^(−1)),and excellent cycling stability with 95.1%capacity retention after 1000 cycles at 1 A g^(−1).展开更多
The precise synthesis of subporphyrinoid hybrids withπ-expanded topologies and unique material properties plays a promising role in the design of functional macrocycles.Easy,selective,and controllable routes to boron...The precise synthesis of subporphyrinoid hybrids withπ-expanded topologies and unique material properties plays a promising role in the design of functional macrocycles.Easy,selective,and controllable routes to boron subphthalocyanine−subnaphthalocyanine hybrids,Bsub(Pc_(3‑p)-Nc_(p))s,are desirable for this purpose yet synthetically challenging due to random mixtures of C_(s-),C_(3v-),and,in some cases,C_(1)-symmetric compounds that form during traditional statistical mixed cyclotrimerizations.Herein,we addressed this issue by developing a sterically driven mixed cyclotrimerization with enhanced selectivity for the targeted C_(s)-symmetric hybrid and complete suppression of sterically crowded macrocyclic byproducts.This process,coupled with a rationally designed precursor bearing bulky phenyl substituents,enabled the synthesis and characterization of bay-position phenylated Ph_(2)-(R_(p))_(8)Bsub(Pc_(2)-Nc_(1))hybrids with halogens(Rp=Cl or F)in their peripheral isoindole rings.Reaction selectivity ranged between 59 and 72%with remarkable yields,significantly higher than that of conventional mixed cyclotrimerizations.These findings were augmented by theoretical calculations on precursor Lewis basicity as guiding principles into hybrid macrocycle formation.Additionally,the incorporation of unfused phenyl groups and halogen atoms into the hybrid framework resulted in fine-tuned optical,structural,electronic,and electrochemical properties.This straightforward approach achieved improved selectivity and controlled narrowing of the product distribution,affording the efficient synthesis of structurally sophisticated Bsub(Pc_(2)-Nc_(1))hybrids.This then expands the library of 3-dimensionalπ-extended macrocycles for use in a range of applications,such as in optoelectronic devices with precisely tailored optical properties.展开更多
Electrochemical nickel-catalyzed syntheses of triphenylenes by a)reductive trimerization of ortho-dibromobenzenes or ortho-bromoarylsulfurofluoridates,or b)reductive cross-coupling of ortho-dibromobenzenes to 2,2’-di...Electrochemical nickel-catalyzed syntheses of triphenylenes by a)reductive trimerization of ortho-dibromobenzenes or ortho-bromoarylsulfurofluoridates,or b)reductive cross-coupling of ortho-dibromobenzenes to 2,2’-diiodobiphenyls,are described.The former provides a practical means for the construction of triphenylene derivatives in up to 87%isolated yield at room temperature.For 1,2-dihalo-3-methylbenzenes and related ortho-trisubstituted substrates,trimerizations proceed with high substrate-controlled regioselectivity for the non-C3h symmetric triphenylene isomer.展开更多
A series-of lanthanide complexes including (Ind)(3)Sm(THF) (1), [(MeCP)(2)Sm(mu-SPh)(THF)](2),(2), [(MeCp)(2)Y(mu-O-i-Pr)](2) (3), (MeCp)(3)Sm.THF (4), Sm(SPh)(3) (hmpa)(3) (5), [(MeCp)(2)Y(mu-OCH2CF3)](2) (6) and (CF...A series-of lanthanide complexes including (Ind)(3)Sm(THF) (1), [(MeCP)(2)Sm(mu-SPh)(THF)](2),(2), [(MeCp)(2)Y(mu-O-i-Pr)](2) (3), (MeCp)(3)Sm.THF (4), Sm(SPh)(3) (hmpa)(3) (5), [(MeCp)(2)Y(mu-OCH2CF3)](2) (6) and (CF3CH2O)(3)Y(THF)(3) (7) were synthesized and they have good activity for the oligomerization of phenyl isocyanate. Among-them 5 shows,the highest activity. The conversion is as high as 96.2%, with 1/2500 of the molar ratio of cat. / PhNCO. The main components in oligomer were characterized to be a cyclodimer and a cyclotrimer. The ratio of cyclodimer,to cyclotrimer depends on the lanthanide complexes:used. 7 gave 85.2% cyclotrimer with 1/300 of the molar ratio of cat./PhNCO at 40 V for 0.5 h, while 5 gave 77.6% cyclodimer with 1/300 of the molar ratio of cat. /PhNCO at 40 degreesC for 4 h.展开更多
基金Supported by the Research Grants Council of Hong Kong (Grant Nos. 602707, 602706, HKU2/05C and 603505)the National Science Foundation of China (Grant No. 20634020)the Ministry of Science and Technology of China (Grant No. 2002CD613401).
文摘This paper presents a new synthetic route to hyperbranched polymer. An arylene bipropiolate monomer,dimethylmethylenebis(1,4-phenylene) bipropiolate,was prepared by a one-step esterification reaction of bisphenol A with propiolic acid. Polycyclotrimrtization of the monomer was effected by reflux in dimethylformamide(DMF),producing a soluble hyperbranched poly(aroxycarbonylphenylene) in a good yield. The polymer was perfectly branched with a degree of branching of 100%.
基金Project supported by the National Natural Science Foundation of China (No. 20202002) Hunan Province Education Department (No. 02C211) and Hunan Normal University (2001).
文摘Carbon dioxide was found as a selective agent to promote the palladium-catalyzed cyclotrimerization of alkynes in water. Both aryl and alkylacetylenes afforded the corresponding cyclotrimerization products regioselectively in high yields using PdCl2, CuCl2, and CO2 as the catalytic system. However, tert-butylacetylene bearing a bulky group gave a dimerization product. Mechanism of this reaction was also discussed.
基金Project supported by the National Natural Science Foundation of China（No. G2000048）.
文摘Aliphatic aldehydes such as ethanal, propanal, n-butanal, isobutyraldehyde, n-valeraldehyde, isovaleraldehyde, n-hexanal and n-octanal were converted into the corresponding 2.4,6-trialkyl-1,3,5-trioxanes through cyclotrimerization in the presence of the ferric chloride based ionic liquids at room temperature without solvent in high selectivity. The effects of different ionic liquids, acidity of ionic liquids and temperature on cyclotrimerization were also studied. The results showed that the ferric chloride based ionic liquids （apparent molar fraction of FeCl3 （x（FeCl3）= 0.62）） were a kind of efficient catalysts for the cyclotrimerization of aliphatic aldehyde which could be separated conveniently from the reaction mixture and recycled without loss of catalytic activity. The conversion of isobutyraldehyde and the selectivity to 2,4,6-triisopropyl-1,3,5-trioxane were 91.1% and 99.8% respectively under optimum reaction condition （isobutyraldehyde 25.0 g, [Et3NH]Cl/FeCl3 （x（FeCl3）=0.62） 1.0 g, 25 ℃ for 1 h）.
基金We graleully appreciate the financial support from the National Natural Science Foundation of China(G2000048).
文摘The synthesis of 2, 4, 6-triisopropyl-1, 3, 5-trioxane with high yield and desirable selec- tivity from solvent-free cyclotrimerization of isobutyraldehyde catalyzed by ionic liquids was reported in this work.
基金support by the National Natural Science Foundation of China(grant nos.22022510 and 51873039)the Science and Technology Innovation Program of Hunan Province(grant no.2021RC2086).
文摘The efficient synthesis of ultrathin crystalline twodimensional(2D)polymers with well-defined repeating units is essential to realize their broad applications but remains a great challenge.Herein,we report a new strategy to directly synthesize a series of few-layer 2D triazine-based polymers(2DTPs)via trimerization reaction of aromatic aldoximes in one step with a high yield of 85%using AlCl3 as catalyst under solvent-free conditions.The obtained 2D-TPs show high crystallinity,a lateral size of several micrometers,an ultrathin thickness less than 2 nm,and good dispersibility and processability.Through semi-in situ and detailed control experiments,we reveal that the 2D polymerization reaction is a two-step process of dehydration and then cyclotrimerization,and AlCl3 acts as not only catalyst but also an in situ generated template for promoting the formation of 2D-TPs.When explored as a new polymeric anode for potassium-ion batteries,the 2D-TP displayed an extraordinary reversible specific capacity of 356 mAh g^(−1)at 0.05 A g^(−1),which is among the best performances ever reported,outstanding rate capability(153 mAh g^(−1)at 1 A g^(−1)),and excellent cycling stability with 95.1%capacity retention after 1000 cycles at 1 A g^(−1).
文摘The precise synthesis of subporphyrinoid hybrids withπ-expanded topologies and unique material properties plays a promising role in the design of functional macrocycles.Easy,selective,and controllable routes to boron subphthalocyanine−subnaphthalocyanine hybrids,Bsub(Pc_(3‑p)-Nc_(p))s,are desirable for this purpose yet synthetically challenging due to random mixtures of C_(s-),C_(3v-),and,in some cases,C_(1)-symmetric compounds that form during traditional statistical mixed cyclotrimerizations.Herein,we addressed this issue by developing a sterically driven mixed cyclotrimerization with enhanced selectivity for the targeted C_(s)-symmetric hybrid and complete suppression of sterically crowded macrocyclic byproducts.This process,coupled with a rationally designed precursor bearing bulky phenyl substituents,enabled the synthesis and characterization of bay-position phenylated Ph_(2)-(R_(p))_(8)Bsub(Pc_(2)-Nc_(1))hybrids with halogens(Rp=Cl or F)in their peripheral isoindole rings.Reaction selectivity ranged between 59 and 72%with remarkable yields,significantly higher than that of conventional mixed cyclotrimerizations.These findings were augmented by theoretical calculations on precursor Lewis basicity as guiding principles into hybrid macrocycle formation.Additionally,the incorporation of unfused phenyl groups and halogen atoms into the hybrid framework resulted in fine-tuned optical,structural,electronic,and electrochemical properties.This straightforward approach achieved improved selectivity and controlled narrowing of the product distribution,affording the efficient synthesis of structurally sophisticated Bsub(Pc_(2)-Nc_(1))hybrids.This then expands the library of 3-dimensionalπ-extended macrocycles for use in a range of applications,such as in optoelectronic devices with precisely tailored optical properties.
基金This work was financially supported by National Key R&D Program of China(No.2021YFA1500100)the NSF of China(Grants 21821002,21772222,and 91956112)+1 种基金the S&TCSM of Shanghai(Grants 18JC1415600 and 20JC1417100)Bayer AG(Germany).
文摘Electrochemical nickel-catalyzed syntheses of triphenylenes by a)reductive trimerization of ortho-dibromobenzenes or ortho-bromoarylsulfurofluoridates,or b)reductive cross-coupling of ortho-dibromobenzenes to 2,2’-diiodobiphenyls,are described.The former provides a practical means for the construction of triphenylene derivatives in up to 87%isolated yield at room temperature.For 1,2-dihalo-3-methylbenzenes and related ortho-trisubstituted substrates,trimerizations proceed with high substrate-controlled regioselectivity for the non-C3h symmetric triphenylene isomer.
文摘A series-of lanthanide complexes including (Ind)(3)Sm(THF) (1), [(MeCP)(2)Sm(mu-SPh)(THF)](2),(2), [(MeCp)(2)Y(mu-O-i-Pr)](2) (3), (MeCp)(3)Sm.THF (4), Sm(SPh)(3) (hmpa)(3) (5), [(MeCp)(2)Y(mu-OCH2CF3)](2) (6) and (CF3CH2O)(3)Y(THF)(3) (7) were synthesized and they have good activity for the oligomerization of phenyl isocyanate. Among-them 5 shows,the highest activity. The conversion is as high as 96.2%, with 1/2500 of the molar ratio of cat. / PhNCO. The main components in oligomer were characterized to be a cyclodimer and a cyclotrimer. The ratio of cyclodimer,to cyclotrimer depends on the lanthanide complexes:used. 7 gave 85.2% cyclotrimer with 1/300 of the molar ratio of cat./PhNCO at 40 V for 0.5 h, while 5 gave 77.6% cyclodimer with 1/300 of the molar ratio of cat. /PhNCO at 40 degreesC for 4 h.
