2875-19-6

Upstream product

• 16297-29-3 2,3,5,6-tetrafluoropyridin-4-yltrimethylsilan 
• 71-43-2 benzene 
• 700-16-3 Pentafluoropyridine 
• 591-51-5 phenyllithium 
• 94-36-0 dibenzoyl peroxide 
• 2875-18-5 2,3,5,6-tetrafluoropyridine 
• 98-80-6 phenylboronic acid 
• 110-86-1 pyridine 
• 836-77-1 perfluoro-N-fluoropiperidine 
• 2375-90-8 4-methoxy-2,3,5,6-tetrafluoropyridine 
• 714-37-4 nonafluoro-2,3,4,5-tetrahydropyridine 
• 17763-67-6 Phenyl triflate 
• 100-58-3 phenylmagnesium bromide 
• 873-55-2 sodium benzenesulfonate 

Relevant academic research and scientific papers

Synthesis and reactivity of the fluoro complex trans -[Pd(F)(4-C 5NF4)(iPr2PCH2CH 2OCH3)2]: C-F bond formation and catalytic C-F bond activation reactions

The reaction of [Pd(Me)2(tmeda)] (tmeda = N,N,N′,N′- tetramethylethylendiamine) with the phosphine iPr2PCH 2CH2OCH3 resulted in the formation of the palladium(0) complex [Pd(iPr2PCH2CH 2OCH3)2] (1). Treatment of 1 with pentafluoropyridine at room temperature yielded the C-F activation product trans-[Pd(F)(4-C5NF4)(iPr2PCH 2CH2OCH3)2] (2). The triflato and bromo complexes trans-[Pd(OTf)(4-C5NF4)( iPr2PCH2CH2OCH3) 2] (4) and trans-[Pd(Br)(4-C5NF4)( iPr2PCH2CH2OCH3) 2] (5) could be prepared on reaction of complex 2 with EtOTf or 3-bromopropene, respectively. Treatment of 2 with Me3SiCl or HBpin (HBpin = 4,4,5,5-tetramethyl-1,3,2-dioxaborolane, pinacolborane) effects the formation of trans-[Pd(Cl)(4-C5NF4)(iPr 2PCH2CH2OCH3)2] (6) and trans-[Pd(H)(4-C5NF4)(iPr2PCH 2CH2OCH3)2] (7). In catalytic experiments pentafluoropyridine could be converted into the 4-aryl- tetrafluoropyridines (8, aryl = Ph; 9, aryl = Tol) and into 2,3,5,6- tetrafluoropyridine in the presence of the boronic acids PhB(OH)2, TolB(OH)2, or HBpin when 5 mol % of 2 is employed as catalyst.

Highly Selective Pd-Catalyzed Direct C-F Bond Arylation of Polyfluoroarenes

A directing-group-free palladium-catalyzed direct arylation of simple polyfluoroarenes with arylboronic acids through selective C-F bond activation is described. The combination of Pd(OAc)2 with BrettPhos was identified as an efficient catalytic system to promote the reaction with high regioselectivity and broad substrate scope. Preliminary mechanistic studies reveal that the oxidative addition of Pd to the C-F bond is involved in the catalytic cycle.

Synthesis, Characterization, and Thermal Properties of Fluoropyridyl-Functionalized Siloxanes of Diverse Polymeric Architectures

High-temperature linear fluoropyridyl silicone-based oils and network elastomers were prepared via hydrosilylation with multifunctional perfluoropyridine (PFP)-based monomers possessing terminally reactive alkenes. Monomers with varying degrees of functionalization were prepared in a scalable manner and in high purity via the facile, regio-selective, nucleophilic aromatic substitution (SNAr) of PFP in good isolated yields. These multi-reactive monomers were polymerized via Pt-catalyzed hydrosilylation with hydride-terminated polydimethylsiloxanes (H-PDMSs) possessing varying degrees of polymerization and cross-linked with the highly functionalized octadimethylhydrosilyl cubic siloxane. These resulting polymers of varying architecture possessed exceptional thermal stability with no onset of degradation up to 430 °C and char yields as high as 62%, under inert pyrolysis conditions when modified with cubic siloxane. Furthermore, by nature of the aliphatic or aromatic content, programmable glass transition temperatures were achieved from these elastomeric materials. Finally, the linear 3,5,6-fluoropyridine PDMS systems demonstrated the ability to undergo regio-controlled post-functionalization via SNAr with 4-bromophenol, allowing access to silicone oils with potentially tailorable properties for desired applications.

Dual Photoredox-/Palladium-Catalyzed Cross-Electrophile Couplings of Polyfluoroarenes with Aryl Halides and Triflates

A visible-light photoredox-/Pd-catalyzed cross-electrophile arylation of polyfluoroarenes with aryl halides and triflates in the presence of dialkylamines is reported for the first time. This synergistic protocol affords access to a series of fluorodiaryls from easily available starting materials under mild and operationally simple conditions. A series of mechanistic experiments, including the stoichiometric reactions of a ligated (aryl)Pd complex, Stern-Volmer fluorescence quenching studies, cyclic voltammetry studies, and UV-vis spectroscopy, were performed to elucidate the potential catalytic pathway in this synergistic process.

Organic semiconductor photocatalyst can bifunctionalize arenes and heteroarenes

Photoexcited electron-hole pairs on a semiconductor surface can engage in redox reactions with two different substrates. Similar to conventional electrosynthesis, the primary redox intermediates afford only separate oxidized and reduced products or, more rarely, combine to one addition product. Here, we report that a stable organic semiconductor material, mesoporous graphitic carbon nitride (mpg-CN), can act as a visible-light photoredox catalyst to orchestrate oxidative and reductive interfacial electron transfers to two different substrates in a two- or three-component system for direct twofold carbon–hydrogen functionalization of arenes and heteroarenes. The mpg-CN catalyst tolerates reactive radicals and strong nucleophiles, is straightforwardly recoverable by simple centrifugation of reaction mixtures, and is reusable for at least four catalytic transformations with conserved activity.

Transition-Metal-Free Catalytic Hydrodefluorination of Polyfluoroarenes by Concerted Nucleophilic Aromatic Substitution with a Hydrosilicate

A transition-metal-free catalytic hydrodefluorination (HDF) reaction of polyfluoroarenes is described. The reaction involves direct hydride transfer from a hydrosilicate as the key intermediate, which is generated from a hydrosilane and a fluoride salt. The eliminated fluoride regenerates the hydrosilicate to complete the catalytic cycle. Dispersion-corrected DFT calculations indicated that the HDF reaction proceeds through a concerted nucleophilic aromatic substitution (CSNAr) process.

Metal-Free Perfluoroarylation by Visible Light Photoredox Catalysis

Visible light and eosin Y catalyze the direct arylation of simple arenes with fluorinated aryl bromides by a photoredox process. The reaction scope is broad in fluorinated compounds and arenes and the general and simple procedure provides a metal-free alt

Palladium-Catalyzed Olefination and Arylation of Polyfluoroarenes Using Molecular Oxygen as the Sole Oxidant

The palladium-catalyzed cross-dehydrogenative-coupling of polyfluoroarenes with alkenes or simple arenes has been developed. The approach is characterized by using atmospheric pressure of molecular oxygen as the sole oxidant, and provides a straightforward and environmentally benign route to functionalized polyfluoroarenes.

Palladium-catalyzed coupling reaction of perfluoroarenes with diarylzinc compounds

This report describes the first Pd0-catalyzed cross-coupling of hexafluorobenzene (C6F6) with diarylzinc compounds to give a variety of pentafluorophenyl arenes. This reaction could be applied to other perfluoroarenes, such as octafluorotoluene, pentafluoropyridine, and perfluoronaphthalene, to give the corresponding polyfluorinated coupling products. The optimal ligand in this catalytic reaction was PCy3, and lithium iodide was indispensable as an additive for the coupling reaction. One of the roles of lithium iodide in this catalytic reaction was to promote the oxidative addition of one Ci￡F bond of C6F 6 to palladium. Stoichiometric reactions revealed that an expected oxidative-addition product, trans-[Pd(C6F5)I(PCy 3)2], generated from the reaction of [Pd(PCy 3)2] with C6F6 in the presence of lithium iodide, was not involved in the catalytic cycle. Instead, a transient three-coordinate, monophosphine-ligated species, [Pd(C6F 5)I(PCy3)], emerged as a potential intermediate in the catalytic cycle. Therefore, we isolated a novel PdII complex, [Pd(C6F5)I(PCy3)(py)], in which pyridine (py) acted as a labile ligand to generate the transient species. In fact, in the presence of lithium iodide, this PdII complex was found to react smoothly with diphenylzinc to give the desired pentafluorophenyl benzene, whereas the same reaction conducted in the absence of lithium iodide resulted in a decreased yield of pentafluorophenyl benzene, which indicated that the other role of lithium iodide was to enhance the reactivity of the organozinc species during the transmetalation step.

Palladium-catalyzed desulfitative direct C-H arylation of electron-deficient polyfluoroarenes with sodium arenesulfinates

The palladium-catalyzed direct arylation of electron-deficient polyfluorobenzenes was developed in the presence of silver carbonate and trisodium phosphate. This protocol allowed use of both electron- deficient and electron-rich aromatic sulfinic acid sodium salts as arylating reagents for the direct arylation of a variety of polyfluoroarenes to produce fluorobiaryls in good to excellent yields, providing a complement to the existing methods for the direct arylation of polyfluoroarenes.