scholarly journals Cross-coupling polymerization at iodophenyl thin films prepared by spontaneous grafting of a diazonium salt

2020 ◽  
Vol 2 ◽  
pp. e6 ◽  
Author(s):  
Nicholas Marshall ◽  
Andres Rodriguez
Keyword(s):  
Thin Films ◽  
Conjugated Polymer ◽  
Surface Coverage ◽  
Diazonium Salt ◽  
Aryl Halide ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Gold Substrates ◽  
Coupling Polymerization

Cross-coupling at aryl halide thin films has been well-established as a technique for the surface-initiated Kumada catalyst transfer polymerization (SI-KCTP), used to produce covalently bound conjugated polymer thin films. In this work, we report that the spontaneous grafting of 4-iodobenzenediazonium tetrafluoroborate on gold substrates creates a durable iodoarene layer which is effective as a substrate for cross-coupling reactions including SI-KCTP. Using cyclic voltammetry of a surface-coupled ferrocene terminating agent, we have measured initiator surface coverage produced by oxidative addition of Pd(t-Bu3P)2 and estimated the rate constant of the termination reaction in the SI-KCTP system with 2-chloromagnesio-5-bromothiophene and Pd(t-Bu3P)2. We used this system to prepare uniform polythiophene thin films averaging 90 nm in thickness.

Cross-Coupling Polymerization at Iodophenyl Thin Films Prepared by Spontaneous Grafting of a Diazonium Salt

2019 ◽  
Author(s):  
Nicholas Marshall ◽  
Andres Rodriguez
Keyword(s):  
Thin Films ◽  
Diazonium Salt ◽  
Cross Coupling ◽  
Coupling Polymerization

Development of a method for the surface-initiated Kumada cross-coupling polymerization based on 4-iodophenyldiazonium salt thin films, and use of this method to make very thick polythiophene brushes.<br>

scholarly journals Cross-Coupling Polymerization at Iodophenyl Thin Films Prepared by Spontaneous Grafting of a Diazonium Salt

2020 ◽  
Author(s):  
Nicholas Marshall ◽  
Andres Rodriguez
Keyword(s):  
Thin Films ◽  
Polymer Film ◽  
Film Growth ◽  
Diazonium Salt ◽  
Cross Coupling ◽  
Chain Termination ◽  
Kinetics Of ◽  
Coupling Polymerization

Development of a method for the surface-initiated Kumada cross-coupling polymerization based on 4-iodophenyldiazonium salt thin films. Studies of the kinetics of chain termination and polymer film growth, and use of this method to make polythiophene brushes.<br>

Conjugated Polymer Nanoparticles by Suzuki–Miyaura Cross-Coupling Reactions in an Emulsion at Room Temperature

2014 ◽  
Vol 47 (19) ◽  
pp. 6531-6539 ◽  
Author(s):  
Duangratchaneekorn Muenmart ◽  
Andrew B. Foster ◽  
Alan Harvey ◽  
Ming-Tsz Chen ◽  
Oscar Navarro ◽  
...  
Keyword(s):  
Conjugated Polymer ◽  
Room Temperature ◽  
Cross Coupling ◽  
Polymer Nanoparticles ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Conjugated Polymer Nanoparticles

scholarly journals Ni-Catalyzed Electrochemical C(sp2)−C(sp3) Cross-Coupling Reactions

2020 ◽  
Author(s):  
Jian Luo ◽  
Bo Hu ◽  
wenda wu ◽  
maowei hu ◽  
Tianbiao Liu
Keyword(s):  
Aryl Halide ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Ambient Conditions ◽  
Acid Modification ◽  
Cross Coupling Reactions ◽  
Cross Coupling Reaction ◽  
Organozinc Reagents ◽  
Industrial Adoption

Nickel (Ni) catalyzed carbon-carbon (C−C) cross-coupling has been considerably developed in last decades and has demonstrated unique reactivities compared to palladium. However, existing Ni catalyzed cross-coupling reactions, despite success in organic synthesis, are still subject to the use of air-sensitive nucleophiles (i.e. Grignard and organozinc reagents), or catalysts (i.e. Ni<sup>0</sup> pre-catalysts), significantly limiting their academic and industrial adoption. Herein, we report that, through electrochemical voltammetry screening and optimization, the redox neutral C(sp<sup>2</sup>)‒C(sp<sup>3</sup>) cross-coupling can be accomplished in an undivided cell configuration using bench-stable aryl halide or β-bromostyrene (electrophiles) and benzylic trifluoroborate (nucleophiles) reactants, non-precious, bench stable catalysts consisting of NiCl<sub>2</sub>•glyme pre-catalyst and polypyridine ligands under ambient conditions. The broad reaction scope and good yields of the Ni-catalyzed electrochemical coupling reaction were confirmed by 48 examples of aryl/β-styrenyl chloride/bromide and benzylic trifluoroborates. Its potential applications were demonstrated by late-stage functionalization of pharmaceuticals and natural amino acid modification. Furthermore, this electrochemical C−C cross-coupling reaction was demonstrated at gram-scale in a flow-cell electrolyzer for practical industrial adoption. Finally, an array of chemical and electrochemical studies mechanistically indicates that electrochemical C−C cross-coupling reaction proceeds through an unconventional radical trans-metalation mechanism.

scholarly journals Ni-Catalyzed Electrochemical C(sp2)−C(sp3) Cross-Coupling Reactions

2020 ◽  
Author(s):  
Jian Luo ◽  
Bo Hu ◽  
wenda wu ◽  
maowei hu ◽  
Tianbiao Liu
Keyword(s):  
Aryl Halide ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Ambient Conditions ◽  
Acid Modification ◽  
Cross Coupling Reactions ◽  
Cross Coupling Reaction ◽  
Organozinc Reagents ◽  
Industrial Adoption

Nickel (Ni) catalyzed carbon-carbon (C−C) cross-coupling has been considerably developed in last decades and has demonstrated unique reactivities compared to palladium. However, existing Ni catalyzed cross-coupling reactions, despite success in organic synthesis, are still subject to the use of air-sensitive nucleophiles (i.e. Grignard and organozinc reagents), or catalysts (i.e. Ni<sup>0</sup> pre-catalysts), significantly limiting their academic and industrial adoption. Herein, we report that, through electrochemical voltammetry screening and optimization, the redox neutral C(sp<sup>2</sup>)‒C(sp<sup>3</sup>) cross-coupling can be accomplished in an undivided cell configuration using bench-stable aryl halide or β-bromostyrene (electrophiles) and benzylic trifluoroborate (nucleophiles) reactants, non-precious, bench stable catalysts consisting of NiCl<sub>2</sub>•glyme pre-catalyst and polypyridine ligands under ambient conditions. The broad reaction scope and good yields of the Ni-catalyzed electrochemical coupling reaction were confirmed by 48 examples of aryl/β-styrenyl chloride/bromide and benzylic trifluoroborates. Its potential applications were demonstrated by late-stage functionalization of pharmaceuticals and natural amino acid modification. Furthermore, this electrochemical C−C cross-coupling reaction was demonstrated at gram-scale in a flow-cell electrolyzer for practical industrial adoption. Finally, an array of chemical and electrochemical studies mechanistically indicates that electrochemical C−C cross-coupling reaction proceeds through an unconventional radical trans-metalation mechanism.

ChemInform Abstract: Conjugated Polymer Stabilized Palladium Nanoparticles as a Versatile Catalyst for Suzuki Cross-Coupling Reactions for Both Aryl and Heteroaryl Bromide Systems.

ChemInform ◽  
2011 ◽  
Vol 42 (38) ◽  
pp. no-no
Author(s):  
Rafique Ul Islam ◽  
Michael J. Witcomb ◽  
Michael S. Scurrell ◽  
Elma van der Lingen ◽  
Willem Van Otterlo ◽  
...  
Keyword(s):  
Conjugated Polymer ◽  
Palladium Nanoparticles ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Polymer Stabilized

scholarly journals Ferrocenylimine Palladium (II) Complexes: Synthesis, Characterization and Application in Mizoroki-Heck and Suzuki-Miyaura Cross-Coupling Reactions

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 755
Author(s):  
Asanda C. Matsheku ◽  
Richard Tia ◽  
Munaka C. Maumela ◽  
Banothile C. E. Makhubela
Keyword(s):  
Density Functional ◽  
Aryl Halide ◽  
Cross Coupling ◽  
Analytical Techniques ◽  
13C Nmr Spectroscopy ◽  
Catalyst Loading ◽  
Moderate Activity ◽  
Coupling Reactions ◽  
Heck Reactions ◽  
Cross Coupling Reactions

Carbon-carbon cross-coupling reactions are essential synthetic tools for synthesizing polymers, natural products, agrochemicals, and pharmaceuticals. Therefore, new catalysts that function with greater efficiency and functional group tolerance are being researched. We have prepared new ferrocenylimine monodentate N and P donor ligands and N^N and N^P bidentate chelating ligands (L1 to L4) employed in stabilizing palladium ions for application in Mizoroki-Heck and Suzuki-Miyaura cross-coupling reactions. The ferrocenylimine ligands were successfully synthesized by Schiff base condensation reactions of acetyl ferrocene with hydrazine monohydrate to afford ferrocenyl hydrazone (L1). Ligand L1 was further treated with aldehydes to give ferrocenyl(2-diphenylphosphino)imine (L3) and ferrocenyl(pyridyl)imine (L3), while phosphination of L1 with chlorodiphenylphosphine afforded L2. The ligands were used to prepare new palladium(II) complexes (C1 to C4) by complexation with [PdCl2(MeCN)2]. All the ligands and complexes were fully characterized using standard spectroscopic and analytical techniques, including 1H NMR and 13C NMR spectroscopy, FT-IR spectroscopy, mass spectrometry and elemental analysis. The complexes (C1 to C4) were tested for efficacies in catalyzing Mizoroki-Heck and Suzuki-Miyaura C-C cross-coupling reactions and proved to be suitable catalyst precursors. Ferrocenyl(2-diphenylphosphine)imino and ferrocenyl-methyl hydrazone palladium(II) complexes C2 and C3 showed the best activities at TONs of up to 201. The ferrocenyl palladium(II) (pre)catalysts demonstrated moderate activity in Mizoroki-Heck reactions involving substrates with substituents on the olefin and aryl halide (including 4-Cl, 4-CH3, -CO2Me and -CO2Et). Density Functional Theory was used to study the mechanism of the Mizoroki-Heck cross-coupling reactions and have led to confirmation of the widely accepted catalytic cycle. Catalyst precursors (C1 to C4) also displayed good activity and selectivity in Suzuki-Miyaura cross-coupling reactions, at 0.5 mol% catalyst loading, with good tolerance to functional groups present on the aryl halide and boronic acid substrates (such as 4-Cl, 4-CHO, 4-COOH, 3-NO2, 3,5-dimethoxy and 4-CH3).

scholarly journals Nickel versus Palladium in Cross-Coupling Catalysis: On the Role of Substrate Coordination to Zerovalent Metal Complexes

Synthesis ◽  
2019 ◽  
Vol 52 (04) ◽  
pp. 565-573 ◽  
Author(s):  
Alasdair K. Cooper ◽  
Paul M. Burton ◽  
David J. Nelson
Keyword(s):  
Functional Groups ◽  
Density Functional ◽  
Aryl Halide ◽  
Cross Coupling ◽  
Density Functional Theory Calculations ◽  
Detailed Comparison ◽  
Coupling Reactions ◽  
Functional Theory ◽  
Cross Coupling Reactions

A detailed comparison of the effect of coordinating functional groups on the performance of Suzuki–Miyaura reactions catalysed by nickel and palladium is reported, using competition experiments, robustness screening, and density functional theory calculations. Nickel can interact with a variety of functional groups, which manifests as selectivity in competitive cross-coupling reactions. The presence of these functional groups on exogenous additives has effects on cross-coupling reactions that range from a slight improvement in yield to the complete cessation of the reaction. In contrast, palladium does not interact sufficiently strongly with these functional groups to induce selectivity in cross-coupling reactions; the selectivity of palladium-catalysed cross-coupling reactions is predominantly governed by aryl halide electronic properties.

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