The rapid synthesis of structurally complicated electron donors&acceptors still remains a major challenge in organic solar cells(OSC).In this work,we developed a highly efficient strategy to access long-chain olig...The rapid synthesis of structurally complicated electron donors&acceptors still remains a major challenge in organic solar cells(OSC).In this work,we developed a highly efficient strategy to access long-chain oligomeric donor and acceptors for OSC applications.A series of cyclopentadithiophene(CPDT)and benzothiadiazole(BT)-basedπ-conjugated oligomers,i.e.,three oligomeric acceptors(BTDT)n-IC(n=1—3)and one long-chain oligomeric donor(BTDT)4-RD,are facilely synthesized by an atom-and step-economical,and labor-saving direct C—H arylation(DACH)reaction(i.e.,C—H/C—Br cross coupling).Note that(BTDT)4-RD involving five CPDT,four BT and two rhodamine(RD)building blocks is the longest oligomeric donor in the fullerene-free OSC devices ever reported.The dependence of the structure-property-performance correlation of(BTDT)n-IC(n=1—3)and(BTDT)4-RD on theπ-conjugation lengths is thoroughly investigated by opto-electrochemical measurements,bulk heterojunction(BHJ)OSC devices and microscopies.The(BTDT)1-IC:PBDB-T and(BTDT)4-RD:Y6 BHJs achieve power conversion efficiencies of 9.14%and 4.51%,respectively.Our findings demonstrate that DACH reaction is a powerful tool to tune the opto-electronic properties and device performances by regulating the lengths ofπ-conjugated oligomers with varied numbers of repeating units.展开更多
α-C(sp^(3))-H arylation is an important type of C-H functionalization.Various biologically significant natural products,chemi-cal intermediates,and drugs have been effectively prepared via C-H functionalization.Cycli...α-C(sp^(3))-H arylation is an important type of C-H functionalization.Various biologically significant natural products,chemi-cal intermediates,and drugs have been effectively prepared via C-H functionalization.Cyclic carbonyl compounds comprise of cyclic ketones,enones,lactones,and lactams.Theα-C(sp^(3))-H arylation of these compounds have been exhibited high efficiency in forming C(sp^(3))-C(sp^(2))bonds,played a crucial role in organic synthesis,and attracted majority of interests from organic and medicinal communities.This review focused on the most significant advances including methods,mechanism,and applications in total synthesis of natural products in the field ofα-C(sp^(3))-H arylations of cyclic carbonyl compounds in recent years.展开更多
Transition-metal-catalyzed remote sp^(2)C-H functionalization of aryl sulfonic acids was hardly ever real-ized owing to competitive ortho-C-H functionalization of aryl sulfonates and electron-deficient nature of pheny...Transition-metal-catalyzed remote sp^(2)C-H functionalization of aryl sulfonic acids was hardly ever real-ized owing to competitive ortho-C-H functionalization of aryl sulfonates and electron-deficient nature of phenyl ring.Herein,with the assistance of a practical biaryl indolyl directing template,palladium-catalyzed remote sp^(2)C-H alkylation of aryl sulfonic acids have been achieved in moderate to good yields with exclusive meta selectivity.Moreover,remote meta-selective C-H alkynylation of aryl sulfonic acids was also accomplished with a rhodium catalyst.These meta-C-H functionalized products proved to be the superior synthetic precursors,which are difficult to access using the conventional strategy.展开更多
Transition metal-catalyzed olefination of aryl C-H bond is a powerful tool for the synthesis of alkenes. While the Pd-catalyzed oxidative C-H olefination of arenes, also known as Fujiwara-Moritani reaction, has been e...Transition metal-catalyzed olefination of aryl C-H bond is a powerful tool for the synthesis of alkenes. While the Pd-catalyzed oxidative C-H olefination of arenes, also known as Fujiwara-Moritani reaction, has been established as one of the most efficient methods, the substrates are largely limited to terminal olefins with electron-withdrawing group(s). Herein, we report a synergistic silver-mediated and palladium-catalyzed non-directed C-H olefination of arenes with vinyl(pseudo)halides, which offers a complementary strategy to the typical Fujiwara-Moritani reaction. The reactions proceeded well for a variety of halogenated arenes, heteroarenes, and olefin substrates, providing an efficient access to various multi-substituted aryl olefins, including trisubstituted/tetrasubstituted olefins and several complex olefins derived from medicines or natural products. Mechanistic studies indicated a bimetallic Pd/Ag cooperation is operative in the catalysis, i.e., the reaction is initiated by aryl C-H bond cleavage via ligation with phosphine/Ag species, followed by transferring of the aryl moiety to a vinyl palladium intermediate,which is in turn formed by oxidative addition of vinyl(pseudo)halide to a Pd complex. This method enables the synthesis of a wide range of challenging multi-substituted vinyl products from simple arenes(directing-group free) in a streamlined and controllable fashion.展开更多
Direct arylation polycondensation(DArP)has emerged as an eco-friendly and atom-efficient methodology for the syntheses ofπ-conjugated polymers(CPs).This approach features the direct C—H arylation of an aromatic hydr...Direct arylation polycondensation(DArP)has emerged as an eco-friendly and atom-efficient methodology for the syntheses ofπ-conjugated polymers(CPs).This approach features the direct C—H arylation of an aromatic hydrocarbon with an aryl halide.Given the prevalence of thiophene-containing CPs,achieving efficient and defect-free DArP of thiophene-based C−H monomers is of great significance.This review presents a mechanistic insight into DArP and describes the development of DArP catalytic systems for varied thiophene-based C−H monomers.Moreover,the control of the primary defects(i.e.,branching and homo-coupling)in thiophene-based DArP is also elaborated.By emphasizing the principles behind monomer selection and catalytic system optimization,this review intends to provide a framework for future advancements in the DArP of thiophene-containing CPs.展开更多
The solubility of a direct arylation polycondensation(DArP)synthesized conjugated polymer,i.e.,poly(3,6-bis(furan-2-yl)-2,5-bis(4-tetradecyloctadecyl)-pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione-alt-1,2-bis(3,4-d ifl uorot...The solubility of a direct arylation polycondensation(DArP)synthesized conjugated polymer,i.e.,poly(3,6-bis(furan-2-yl)-2,5-bis(4-tetradecyloctadecyl)-pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione-alt-1,2-bis(3,4-d ifl uorothien-2-yl)ethene)(PFuD PP-4FTVT),in variou s organic solvents was studied.The polymer is soluble in 3-methylcyclohexanone(3-MC),a green solvent from peppermint oil,besides other solvents such as anisole,cyclopentyl methyl ether(CPME)and o-dichlorobenzene(o-DCB),etc.Based on the Hansen solu bility parameters(HSP)analysis,3-MC is identified as a"marginal solvent"of PFuDPP-4FTVT.The morphology of the spin-coated films with 3-MC as the solvent strongly correlated with the solution preparation conditions.With a 3-MC solution aged for 3 h at 70℃,n-channel organic thin-film transistors(OTFTs)with electron mobility(μe)above 1 cm^(2)·V^(-1)·s^(-1) and current on/off ratio(Ion/Ioff)higher than 105 were fabricated by spin-coating.This is the first report on high mobility conjugated polymers for OTFTs processible with natu rally occurred green solvent.展开更多
As the high calibre candidate of lightweight and flexible solar cells,polymer solar cells(PSCs)have made tremendous progress in recent years.However,the active photovoltaic materials in PSCs are mainly synthesized by ...As the high calibre candidate of lightweight and flexible solar cells,polymer solar cells(PSCs)have made tremendous progress in recent years.However,the active photovoltaic materials in PSCs are mainly synthesized by metal-mediated coupling reaction requiring harsh reaction conditions,multiple-step synthesis,and cumbersome purification,which is not cost-efficient and may bring toxicity concerns.It is not favorable to the production of photovoltaic polymers and PSC devices on a large scale,and therefore unsuitable for the PSCs industrialization.Direct arylation coupling reaction via aromatic C―H bonds activation enables the synthesis of conjugated polymers under mild conditions and simultaneously reduces synthetic steps,difficulty,and toxic reaction byproducts.This review provides an overview of the history of preparing representative photovoltaic polymers utilized in PSCs through direct arylation reactions and discusses the activity and selectivity of C―H bonds in typical building blocks under different reaction conditions.Especially,the impact of direct arylation condition on defect formation and photovoltaic performance of the photovoltaic polymers is addressed and compared with conventional Stille coupling methods.展开更多
Two novel heterocyclic diamine monomers: 1,2-dihydro-2-(4-aminophenyl)-4-[4-(4-aminophenoxy)phenyl] (2H)phthalazin-1-one and 1,2-dihydro-2-(4-aminophenyl)-4-[4-(4-aminophenoxy)-3,5-dimethylphenyl](2H)phthalazin-1-one ...Two novel heterocyclic diamine monomers: 1,2-dihydro-2-(4-aminophenyl)-4-[4-(4-aminophenoxy)phenyl] (2H)phthalazin-1-one and 1,2-dihydro-2-(4-aminophenyl)-4-[4-(4-aminophenoxy)-3,5-dimethylphenyl](2H)phthalazin-1-one were successfully synthesized from readily available heterocyclic bisphenol-like monomers in two steps in high yield. A series of novel poly(aryl ether amide)s containing the phthalazinone moiety were successfully prepared by the direct polymerization of the novel diamines and aromatic dicarboxylic acids using triphenyl phosphite and pyridine as condensing agents.展开更多
Rh(Ⅲ)-catalyzed, chelation-assisted oxidative C-H imidation of arenes with N-H imide have been realized using PhI(OAc)2 as an oxidant. This transformation exhibits a broad substrate scope and tolerates various functi...Rh(Ⅲ)-catalyzed, chelation-assisted oxidative C-H imidation of arenes with N-H imide have been realized using PhI(OAc)2 as an oxidant. This transformation exhibits a broad substrate scope and tolerates various functional groups. The reaction proceeded via in situ generation of an iodine(Ⅲ) imido. DFT calculations suggest that this oxidative imidaton system proceeds via a Rh(Ⅲ)-Rh(Ⅴ)-Rh(Ⅲ) pathway.展开更多
A highly efficient and eco-friendly protocol for the synthesis of an alternating copolymer poly(7,7'-diazaisoindigo-alt-(E)-1,2- bis(3,4-difluorothien-2-yl)ethene)(PAIID-4FTVT) via direct arylation polycondensatio...A highly efficient and eco-friendly protocol for the synthesis of an alternating copolymer poly(7,7'-diazaisoindigo-alt-(E)-1,2- bis(3,4-difluorothien-2-yl)ethene)(PAIID-4FTVT) via direct arylation polycondensation (DArP) is presented. Through detailed study, we found that the inhibitory effect of 7,7'-diazaisoindigo on DArP stemmed from the coordination of N atom with catalyst can be overcome by using dimethylacetamide (DMAc) as the co-solvent. Thus, PAIID-4FTVT with number-average molecular weight (Mn)>100kDa was synthesized via DArP by optimizing the content of DMAc. Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectroscopy revealed that PAIID-4FTVT was defect-free. Top gate and bottom contact (TG/BC) organic thin-film transistors (OTFTs) were fabricated to characterize the semiconducting properties of the polymers. PAIID-4FTVT displayed unipolar n-type characteristics with the electron mobility (μe) strongly dependent on Mn. The highest μe up to 0.25 cm^2·V^-1 s^-1 was achieved with the high molecular weight sample.展开更多
Direct arylation methods have been used to polymerize thienylmethylene oxindoles(TEIs)and 3,3-bis[[(2-ethylhexyl)oxy]methyl]-3,4-dihydro-2 H-thieno-[3,4-b][1,4]dioxepin(ProDOT)for new donor-acceptor conjugated polymer...Direct arylation methods have been used to polymerize thienylmethylene oxindoles(TEIs)and 3,3-bis[[(2-ethylhexyl)oxy]methyl]-3,4-dihydro-2 H-thieno-[3,4-b][1,4]dioxepin(ProDOT)for new donor-acceptor conjugated polymers.The polymers exhibited blue hues in neutralstate with distinct color-to-transmissive reversible electrochromic switching under applied potentials from 0 V to+1.5 V,and showed high coloration efficiencies(436-438 cm^(2)·C^(-1))in near-infrared regions with high switching speeds around 1-2 s under ambient conditions.展开更多
Herein, we report that a series of novel palladium(II)-NHC complexes (NHC=N-heterocyclic carbene) were synthesized. The structures of all novel complexes were characterized by ^1H NMR, ^13C NMR, FT-IR spectroscopy...Herein, we report that a series of novel palladium(II)-NHC complexes (NHC=N-heterocyclic carbene) were synthesized. The structures of all novel complexes were characterized by ^1H NMR, ^13C NMR, FT-IR spectroscopy and elemental analysis techniques. These palladium(ll)-NHC complexes were tested as efficient catalysts in the direct C-H bond activation of benzoxazole and benzothiazole with aryl bromides in the presence of 1 mol% catalyst loading at 150 ℃ for 4 h. Under the given conditions, various aryl bromides were successfully applied as the arylating reagents to achieve the 2-arylbenzoxazoles and 2-arylbenzothiazoles in acceptable to high yields.展开更多
Four thiophene derivatives were prepared by replacing the 3,4 positions of thiophene by―OCH3, ―CH3―COOCH3 and ―CN, respectively. The polycondensations via direct arylation took place between the four thiophene der...Four thiophene derivatives were prepared by replacing the 3,4 positions of thiophene by―OCH3, ―CH3―COOCH3 and ―CN, respectively. The polycondensations via direct arylation took place between the four thiophene derivatives and 2,7-dibromo-9,9-dioctylfluorene under six various catalytic conditions to investigate the substituent effects. The substituent can affect the electron cloud density of the active C―H bond, which can be monitored by the NMR chemical shift. The experimental results show that the reactivity decreases with increasing the chemical shift of active C―H bonds in the four thiophene derivatives, and thus can promote the direct arylation polycondensation. This phenomenon is explained by the electrophilic aromatic substitution(SEAr) mechanism. UV-Visible absorption and photoluminescence were studied to investigate the substituent effect on optical properties of the four copolymers. The results show that these alternating fluorene-thiophene copolymers with different substituents are good fluorescent materials and promising in PLED applications.展开更多
Privileged biaryl frameworks,BINOL and NOBIN,were efficiently constructed with sole 1-DNQs as arylation reagents under one set of reaction conditions.The judicious selection of palladium-catalytic system plays a pivot...Privileged biaryl frameworks,BINOL and NOBIN,were efficiently constructed with sole 1-DNQs as arylation reagents under one set of reaction conditions.The judicious selection of palladium-catalytic system plays a pivotal role in the excellent selectivities.This transformation accommodated fairly broad substrate generality for both 2-naphthol and N-Boc-2-naphthylamine and afforded the structurally diversified BINOLs and NOBIN derivatives in high efficiency.Notably,the bromosubstituents which cannot survive in conventional palladium-catalyzed reactions were well-compatible with this set of conditions,providing an effective handle for further enriching the library of BINOLs and NOBINs.Preliminary attempts on the asymmetric variant of this reaction were also performed with up to 80:20 er for BINOLs synthesis.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
基金The National Natural Science Foundation of China(No.22169009)Jiangxi Provincial Natural Science Foundation(No.20212ACB204007)Jiangxi Provincial Key Laboratory of Functional Molecular Materials Chemistry(20212BCD42018)are appreciated for financial support。
文摘The rapid synthesis of structurally complicated electron donors&acceptors still remains a major challenge in organic solar cells(OSC).In this work,we developed a highly efficient strategy to access long-chain oligomeric donor and acceptors for OSC applications.A series of cyclopentadithiophene(CPDT)and benzothiadiazole(BT)-basedπ-conjugated oligomers,i.e.,three oligomeric acceptors(BTDT)n-IC(n=1—3)and one long-chain oligomeric donor(BTDT)4-RD,are facilely synthesized by an atom-and step-economical,and labor-saving direct C—H arylation(DACH)reaction(i.e.,C—H/C—Br cross coupling).Note that(BTDT)4-RD involving five CPDT,four BT and two rhodamine(RD)building blocks is the longest oligomeric donor in the fullerene-free OSC devices ever reported.The dependence of the structure-property-performance correlation of(BTDT)n-IC(n=1—3)and(BTDT)4-RD on theπ-conjugation lengths is thoroughly investigated by opto-electrochemical measurements,bulk heterojunction(BHJ)OSC devices and microscopies.The(BTDT)1-IC:PBDB-T and(BTDT)4-RD:Y6 BHJs achieve power conversion efficiencies of 9.14%and 4.51%,respectively.Our findings demonstrate that DACH reaction is a powerful tool to tune the opto-electronic properties and device performances by regulating the lengths ofπ-conjugated oligomers with varied numbers of repeating units.
基金We gratefully acknowledge financial support from the National Science of Foundation of China(81960631)the Yunnan Fundamental Research Project(202001AS070038)+1 种基金the Top Young Talent of Ten Thousand Talents Program of Yunnan Province(R.Zhan and L.-D Shao)the Start-up Fund of Yunnan University of Chinese Medicine(2019YZG03).
文摘α-C(sp^(3))-H arylation is an important type of C-H functionalization.Various biologically significant natural products,chemi-cal intermediates,and drugs have been effectively prepared via C-H functionalization.Cyclic carbonyl compounds comprise of cyclic ketones,enones,lactones,and lactams.Theα-C(sp^(3))-H arylation of these compounds have been exhibited high efficiency in forming C(sp^(3))-C(sp^(2))bonds,played a crucial role in organic synthesis,and attracted majority of interests from organic and medicinal communities.This review focused on the most significant advances including methods,mechanism,and applications in total synthesis of natural products in the field ofα-C(sp^(3))-H arylations of cyclic carbonyl compounds in recent years.
基金Financial support from the National Natural Science Foundation of China(No.22171145 to Z.Jin,32072440 to X.Xu)is gratefully acknowledged.
文摘Transition-metal-catalyzed remote sp^(2)C-H functionalization of aryl sulfonic acids was hardly ever real-ized owing to competitive ortho-C-H functionalization of aryl sulfonates and electron-deficient nature of phenyl ring.Herein,with the assistance of a practical biaryl indolyl directing template,palladium-catalyzed remote sp^(2)C-H alkylation of aryl sulfonic acids have been achieved in moderate to good yields with exclusive meta selectivity.Moreover,remote meta-selective C-H alkynylation of aryl sulfonic acids was also accomplished with a rhodium catalyst.These meta-C-H functionalized products proved to be the superior synthetic precursors,which are difficult to access using the conventional strategy.
基金supported by the National Key R&D Program of China(2021YFA1500100)the National Natural Science Foundation of China(21821002,92256303,22171278)+1 种基金Shanghai Science and Technology Committee(23ZR1482400)the Natural Science Foundation of Ningbo(2023J034)。
文摘Transition metal-catalyzed olefination of aryl C-H bond is a powerful tool for the synthesis of alkenes. While the Pd-catalyzed oxidative C-H olefination of arenes, also known as Fujiwara-Moritani reaction, has been established as one of the most efficient methods, the substrates are largely limited to terminal olefins with electron-withdrawing group(s). Herein, we report a synergistic silver-mediated and palladium-catalyzed non-directed C-H olefination of arenes with vinyl(pseudo)halides, which offers a complementary strategy to the typical Fujiwara-Moritani reaction. The reactions proceeded well for a variety of halogenated arenes, heteroarenes, and olefin substrates, providing an efficient access to various multi-substituted aryl olefins, including trisubstituted/tetrasubstituted olefins and several complex olefins derived from medicines or natural products. Mechanistic studies indicated a bimetallic Pd/Ag cooperation is operative in the catalysis, i.e., the reaction is initiated by aryl C-H bond cleavage via ligation with phosphine/Ag species, followed by transferring of the aryl moiety to a vinyl palladium intermediate,which is in turn formed by oxidative addition of vinyl(pseudo)halide to a Pd complex. This method enables the synthesis of a wide range of challenging multi-substituted vinyl products from simple arenes(directing-group free) in a streamlined and controllable fashion.
基金This work was financially supported by the National Key R&D Program of China(2021YFA0717900)National Natural Science Foundation of China(no.51933008,22222506 and 52121002).
文摘Direct arylation polycondensation(DArP)has emerged as an eco-friendly and atom-efficient methodology for the syntheses ofπ-conjugated polymers(CPs).This approach features the direct C—H arylation of an aromatic hydrocarbon with an aryl halide.Given the prevalence of thiophene-containing CPs,achieving efficient and defect-free DArP of thiophene-based C−H monomers is of great significance.This review presents a mechanistic insight into DArP and describes the development of DArP catalytic systems for varied thiophene-based C−H monomers.Moreover,the control of the primary defects(i.e.,branching and homo-coupling)in thiophene-based DArP is also elaborated.By emphasizing the principles behind monomer selection and catalytic system optimization,this review intends to provide a framework for future advancements in the DArP of thiophene-containing CPs.
基金financially supported by the National Natural Science Foundation of China(Nos.51933008 and 52121002)the Fundamental Research Funds for the Central Universities。
文摘The solubility of a direct arylation polycondensation(DArP)synthesized conjugated polymer,i.e.,poly(3,6-bis(furan-2-yl)-2,5-bis(4-tetradecyloctadecyl)-pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione-alt-1,2-bis(3,4-d ifl uorothien-2-yl)ethene)(PFuD PP-4FTVT),in variou s organic solvents was studied.The polymer is soluble in 3-methylcyclohexanone(3-MC),a green solvent from peppermint oil,besides other solvents such as anisole,cyclopentyl methyl ether(CPME)and o-dichlorobenzene(o-DCB),etc.Based on the Hansen solu bility parameters(HSP)analysis,3-MC is identified as a"marginal solvent"of PFuDPP-4FTVT.The morphology of the spin-coated films with 3-MC as the solvent strongly correlated with the solution preparation conditions.With a 3-MC solution aged for 3 h at 70℃,n-channel organic thin-film transistors(OTFTs)with electron mobility(μe)above 1 cm^(2)·V^(-1)·s^(-1) and current on/off ratio(Ion/Ioff)higher than 105 were fabricated by spin-coating.This is the first report on high mobility conjugated polymers for OTFTs processible with natu rally occurred green solvent.
基金the National Natural Science Foundation of China(No.51773046)the Fundamental Research Funds for the Central Universities,the School of Materials Science and Engineering,Shaanxi Normal Universitythe Project of Key Laboratory of Organic Synthesis of Jiangsu Province,College of Chemistry Chemical Engineering and Materials Science,Soochow University。
文摘As the high calibre candidate of lightweight and flexible solar cells,polymer solar cells(PSCs)have made tremendous progress in recent years.However,the active photovoltaic materials in PSCs are mainly synthesized by metal-mediated coupling reaction requiring harsh reaction conditions,multiple-step synthesis,and cumbersome purification,which is not cost-efficient and may bring toxicity concerns.It is not favorable to the production of photovoltaic polymers and PSC devices on a large scale,and therefore unsuitable for the PSCs industrialization.Direct arylation coupling reaction via aromatic C―H bonds activation enables the synthesis of conjugated polymers under mild conditions and simultaneously reduces synthetic steps,difficulty,and toxic reaction byproducts.This review provides an overview of the history of preparing representative photovoltaic polymers utilized in PSCs through direct arylation reactions and discusses the activity and selectivity of C―H bonds in typical building blocks under different reaction conditions.Especially,the impact of direct arylation condition on defect formation and photovoltaic performance of the photovoltaic polymers is addressed and compared with conventional Stille coupling methods.
文摘Two novel heterocyclic diamine monomers: 1,2-dihydro-2-(4-aminophenyl)-4-[4-(4-aminophenoxy)phenyl] (2H)phthalazin-1-one and 1,2-dihydro-2-(4-aminophenyl)-4-[4-(4-aminophenoxy)-3,5-dimethylphenyl](2H)phthalazin-1-one were successfully synthesized from readily available heterocyclic bisphenol-like monomers in two steps in high yield. A series of novel poly(aryl ether amide)s containing the phthalazinone moiety were successfully prepared by the direct polymerization of the novel diamines and aromatic dicarboxylic acids using triphenyl phosphite and pyridine as condensing agents.
文摘Rh(Ⅲ)-catalyzed, chelation-assisted oxidative C-H imidation of arenes with N-H imide have been realized using PhI(OAc)2 as an oxidant. This transformation exhibits a broad substrate scope and tolerates various functional groups. The reaction proceeded via in situ generation of an iodine(Ⅲ) imido. DFT calculations suggest that this oxidative imidaton system proceeds via a Rh(Ⅲ)-Rh(Ⅴ)-Rh(Ⅲ) pathway.
基金financially supported by the National Key R&D Program of “Strategic Advanced Electronic Materials” (No. 2016YFB0401101) of the Chinese Ministry of Science and Technologythe National Natural Science Foundation of China (No. 51333006)
文摘A highly efficient and eco-friendly protocol for the synthesis of an alternating copolymer poly(7,7'-diazaisoindigo-alt-(E)-1,2- bis(3,4-difluorothien-2-yl)ethene)(PAIID-4FTVT) via direct arylation polycondensation (DArP) is presented. Through detailed study, we found that the inhibitory effect of 7,7'-diazaisoindigo on DArP stemmed from the coordination of N atom with catalyst can be overcome by using dimethylacetamide (DMAc) as the co-solvent. Thus, PAIID-4FTVT with number-average molecular weight (Mn)>100kDa was synthesized via DArP by optimizing the content of DMAc. Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectroscopy revealed that PAIID-4FTVT was defect-free. Top gate and bottom contact (TG/BC) organic thin-film transistors (OTFTs) were fabricated to characterize the semiconducting properties of the polymers. PAIID-4FTVT displayed unipolar n-type characteristics with the electron mobility (μe) strongly dependent on Mn. The highest μe up to 0.25 cm^2·V^-1 s^-1 was achieved with the high molecular weight sample.
基金financially supported by the National Natural Science Foundation of China(Nos.21674060 and 51603123)。
文摘Direct arylation methods have been used to polymerize thienylmethylene oxindoles(TEIs)and 3,3-bis[[(2-ethylhexyl)oxy]methyl]-3,4-dihydro-2 H-thieno-[3,4-b][1,4]dioxepin(ProDOT)for new donor-acceptor conjugated polymers.The polymers exhibited blue hues in neutralstate with distinct color-to-transmissive reversible electrochromic switching under applied potentials from 0 V to+1.5 V,and showed high coloration efficiencies(436-438 cm^(2)·C^(-1))in near-infrared regions with high switching speeds around 1-2 s under ambient conditions.
文摘Herein, we report that a series of novel palladium(II)-NHC complexes (NHC=N-heterocyclic carbene) were synthesized. The structures of all novel complexes were characterized by ^1H NMR, ^13C NMR, FT-IR spectroscopy and elemental analysis techniques. These palladium(ll)-NHC complexes were tested as efficient catalysts in the direct C-H bond activation of benzoxazole and benzothiazole with aryl bromides in the presence of 1 mol% catalyst loading at 150 ℃ for 4 h. Under the given conditions, various aryl bromides were successfully applied as the arylating reagents to achieve the 2-arylbenzoxazoles and 2-arylbenzothiazoles in acceptable to high yields.
基金financially supported by the National Natural Science Foundation of China(Nos.60976019 and 61250016)Education Department Program(No.JA12069)and Program for Innovative Research Team in Science and Technology in Fujian Province
文摘Four thiophene derivatives were prepared by replacing the 3,4 positions of thiophene by―OCH3, ―CH3―COOCH3 and ―CN, respectively. The polycondensations via direct arylation took place between the four thiophene derivatives and 2,7-dibromo-9,9-dioctylfluorene under six various catalytic conditions to investigate the substituent effects. The substituent can affect the electron cloud density of the active C―H bond, which can be monitored by the NMR chemical shift. The experimental results show that the reactivity decreases with increasing the chemical shift of active C―H bonds in the four thiophene derivatives, and thus can promote the direct arylation polycondensation. This phenomenon is explained by the electrophilic aromatic substitution(SEAr) mechanism. UV-Visible absorption and photoluminescence were studied to investigate the substituent effect on optical properties of the four copolymers. The results show that these alternating fluorene-thiophene copolymers with different substituents are good fluorescent materials and promising in PLED applications.
基金supported by the National Natural Science Foundation of China(21825105)the Guangdong Provincial Key Laboratory of Catalysis(2020B121201002)+2 种基金the Guangdong Innovative Program(2019BT02Y335)the Shenzhen Nobel Prize Scientists Laboratory Project(C17213101)the SUSTech Special Fund for the Construction of High-Level Universities(G02216402)。
文摘Privileged biaryl frameworks,BINOL and NOBIN,were efficiently constructed with sole 1-DNQs as arylation reagents under one set of reaction conditions.The judicious selection of palladium-catalytic system plays a pivotal role in the excellent selectivities.This transformation accommodated fairly broad substrate generality for both 2-naphthol and N-Boc-2-naphthylamine and afforded the structurally diversified BINOLs and NOBIN derivatives in high efficiency.Notably,the bromosubstituents which cannot survive in conventional palladium-catalyzed reactions were well-compatible with this set of conditions,providing an effective handle for further enriching the library of BINOLs and NOBINs.Preliminary attempts on the asymmetric variant of this reaction were also performed with up to 80:20 er for BINOLs synthesis.
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.