Nickel-catalyzed Dehydrobrominative Polycondensation for the Practical Preparation of Regioregular Poly(3-substituted thiophene)s

Tamba, Shunsuke; Tanaka, Shota; Okubo, Youhei; Meguro, Hikaru; Okamoto, Shuji; Mori, Atsunori

doi:10.1246/cl.2011.398

Cited by 93 publications

(49 citation statements)

References 34 publications

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“…Using the corresponding nucleophilic thiolate with bromo-alkanes provided facile access to 3-(alkylthio) thiophenes. Selective mono-bromination using NBS and ultrasound 17b afforded the mono-brominated products, which were used for a Kumada polymerization 18 as the next step to produce regioregular polythiophenes in high yields. Knochel’s base was used to deprotonate the monomer, and 0.5 mol% NiCl 2 (dppe) was chosen as the catalyst to promote the polymerization.…”

Section: Resultsmentioning

confidence: 99%

Insights into Magneto-Optics of Helical Conjugated Polymers

et al. 2018

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Materials with magneto-optic (MO) properties have enabled critical fiber-optic applications and highly sensitive magnetic field sensors. While traditional MO materials are inorganic in nature, new generations of MO materials based on organic semi-conducting polymers could allow increased versatility for device architectures, manufacturing options, and flexible mechanics. However, the origin of MO activity in semiconducting polymers is far from understood. In this paper, we report high MO activity observed in a chiral helical poly-3-(alkylsulfone)thiophene (P3AST), which confirms a new design for the creation of giant Faraday effect with Verdet constants up to (7.63±0.78)×104 deg T−1 m−1 at 532 nm. We have determined that the sign of the Verdet constant and its magnitude are related to the helicity of the polymer at the measured wavelength. The Faraday rotation and the helical conformation of P3AST are modulated by thermal annealing, which is further supported by DFT and MD simulations. Our results demonstrate that helical polymers exhibit enhanced Verdet constants, and expand the previous design space for polythiophene MO materials that was thought to be limited to highly regular lamellar structures. The structure property studies herein provide insights for the design of next generation MO materials based upon semiconducting organic polymers.

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Section: Resultsmentioning

confidence: 99%

Insights into Magneto-Optics of Helical Conjugated Polymers

et al. 2018

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“…When the reaction was carried out with 0.5 mol% of NiCl 2 (dppe) as a catalyst, the corresponding HT P3HT (1) was obtained in a quantitative yield. 18 The obtained polymer 3 exhibited extremely high HT selectivity. DPPP as a ligand of the nickel catalyst also was equally effective to DPPE, while DPPB or tricyclohexylphosphine (PCy 3 ) was found inferior.…”

Section: H Functionalization Polymerization Of Thiophenesmentioning

confidence: 94%

Transition Metal-catalyzed Bond-forming Reactions at the C-H Bond of Heteroaromatic Compounds

Mori

2011

J. Synth. Org. Chem. Jpn.

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Recent progress in the C H coupling reactions of heteroaromatic compounds in our group is summarized. Coupling of thiophene derivatives occurs in the presence of a nickel or palladium catalyst with a base as an additive. Lithium t butoxide and several magnesium amides are effective for the coupling reaction of aryl chlorides, bromides, and iodides. Coupling at the C H bond of thiophene with thienyl halides also occurs smoothly forming a thiophene thiophene bond. The reaction is successfully applied to the polymerization of 2 halo 3 substituted thiophenes leading to highly regioregular head to tail type poly(3 substituted thiophene)s. The reaction of thiazole at the C H bond (2 position) with several secondary amines induces C H, N H coupling with a copper catalyst. J. Synth. Org. Chem., Jpn. 1202In considering the reaction mechanism of thiazoles and thiophenes as shown in Scheme 3, the key for the catalytic reaction would be the palladation reaction at the C H bond. The organopalladium intermediate Aryl Pd Th (Th thiophene) can undergo reductive elimination leading to the arylation product accompanied by the formation of palladium(0). There would be two possible pathways for the formation of Aryl Pd Th: Nucleophilic substitution of a heteroaromatic carbanion, which is formed by proton abstraction, to palladium(II) (path a), or electrophilic attack to palladium and following re aromatization (path b). The former is expected to occur at the acidic C H bond such as the 2 position of thiazole, whereas an electron enriched carbon such as the 5 position of thiazole or the 2 position of thiophene would favor the latter.However, proton abstraction at the less acidic C H bond at the 2 position of thiophene may also be possible if a stronger base is employed and that such new reaction systems may open fresh vistas for the C H functionalization of heteroaromatic compounds. Indeed, this has been recently demonstrated for several coupling reactions with heteroaromatic compounds at various types of C H bonds in the presence of a copper catalyst, in which group I alkoxides, magnesium and zinc amides have been successfully utilized.11 Herewith, our recent efforts on the C H functionalization of thiophene derivatives using relatively stronger bases and transition metal catalysis for the purpose of synthesizing advanced materials with extended π conjugation, and particularly those directed to the preparation of oligothiophenes and polythiophenes are described.On the other hand, it is also important to develop catalytic reactions forming carbon heteroatom bonds as well as the extensively studied carbon carbon bond forming cross coupling reactions. Buchwald Hartwig amination with a nickel or palladium catalyst for the coupling of aromatic halide and amines has been a highly effective protocol to form a carbon nitrogen bond.12 Accordingly, the reaction of amines at a C H bond of heteroaromatic compounds is intriguing as an alternative choice. Our recent efforts concerning a novel C H, N H coupling of azoles using a copper ...

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“…48 times when t-BuMgCl and 2,5-dibromo-3-hexylthiophene 4 are used at room temperature ($20 h). To overcome this problem, the authors used LiCl as an additive to effectively accelerate the active monomer formation ($4 h).…”

Section: Scheme 15mentioning

confidence: 99%

Poly(3-hexylthiophene): synthetic methodologies and properties in bulk heterojunction solar cells

Marrocchi

Lanari

Facchetti

et al. 2012

Energy Environ. Sci.

206

131

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Poly(3-hexylthiophene) (P3HT) remains of significant importance as a prototypical benchmark hole conductor material in Organic Photovoltaics (OPVs). In this review we discuss synthetic strategies to P3HT, particularly focusing on those leading to the regioregular form and discussing key physical and morphological properties. Finally, a survey and a brief discussion of P3HT performance in bulkheterojunction (BHJ) OPVs are also provided.

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Nickel-catalyzed Dehydrobrominative Polycondensation for the Practical Preparation of Regioregular Poly(3-substituted thiophene)s

Cited by 93 publications

References 34 publications

Insights into Magneto-Optics of Helical Conjugated Polymers

Insights into Magneto-Optics of Helical Conjugated Polymers

Transition Metal-catalyzed Bond-forming Reactions at the C-H Bond of Heteroaromatic Compounds

Poly(3-hexylthiophene): synthetic methodologies and properties in bulk heterojunction solar cells

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