Copper-Mediated Oxidative Chloro- and Bromodifluoromethylation of Phenols.

The first oxidative chloro- and bromodifluoromethylation of phenols with (CH3)3SiCF2X and CuX (X = Cl or Br) in the presence of Selectfluor under mild reaction conditions was developed. This protocol provided a practical and efficient method for the synthesis of a diverse range of biologically valuable and synthetically challenging chloro- and bromodifluoromethyl aryl ethers. Preliminary mechanistic studies suggest that this reaction proceeded through a difluorocarbene-involved oxidative coupling process.

Visible-light-induced nickel-catalyzed α-hydroxytrifluoroethylation of alkyl carboxylic acids: Access to trifluoromethyl alkyl acyloins.

A visible-light-induced nickel-catalyzed cross coupling of alkyl carboxylic acids with N-trifluoroethoxyphthalimide is described. Under purple light irradiation, an α-hydroxytrifluoroethyl radical generated from a photoactive electron donor-acceptor complex between Hantzsch ester and N-trifluoroethoxyphthalimide was subsequently engaged in a nickel-catalyzed coupling reaction with in situ-activated alkyl carboxylic acids. This convenient protocol does not require photocatalysts and metal reductants, providing a straightforward and efficient access to trifluoromethyl alkyl acyloins in good yields with broad substrate compatibility. The complex bioactive molecules were also compatible with this catalytic system to afford the corresponding products.

Decreased AKAP4/PKA signaling pathway in high DFI sperm affects sperm capacitation.

The sperm DNA fragmentation index (DFI) is a metric used to assess DNA fragmentation within sperm. During in vitro fertilization-embryo transfer (IVF-ET), high sperm DFI can lead to a low fertilization rate, poor embryo development, early miscarriage, etc. A kinase anchoring protein (AKAP) is a scaffold protein that can bind protein kinase A (PKA) to subcellular sites of specific substrates and protects the biophosphorylation reaction. Sperm protein antigen 17 (SPA17) can also bind to AKAP. This study intends to explore the reason for the decreased fertilization rate observed in high sperm DFI (H-DFI) patients during IVF-ET. In addition, the study investigates the expression of AKAP, protein kinase A regulatory subunit (PKARII), and SPA17 between H-DFI and low sperm DFI (L-DFI) patients. SPA17 at the transcriptional level is abnormal, the translational level increases in H-DFI patients, and the expression of AKAP4/PKARII protein decreases. H2O2 has been used to simulate oxidative stress damage to spermatozoa during the formation of sperm DFI. It indicates that H2O2 increases the expression of sperm SPA17 protein and suppresses AKAP4/PKARII protein expression. These processes inhibit sperm capacitation and reduce acrosomal reactions. Embryo culture data and IVF outcomes have been documented. The H-DFI group has a lower fertilization rate. Therefore, the results indicate that the possible causes for the decreased fertilization rate in the H-DFI patients have included loss of sperm AKAP4/PKARII proteins, blocked sperm capacitation, and reduced occurrence of acrosome reaction.

N-Trifluoromethoxyphthalimide: A Shelf-Stable Reagent for Nucleophilic Trifluoromethoxylation.

Due to the unique properties of the OCF3 group, trifluoromethyl ether compounds play an important role in pharmaceuticals and agrochemicals. Recently, considerable attention has been focused on the development of practical and convenient reagents for the direct incorporation of the OCF3 group into organic compounds. Herein, we reported a new trifluoromethoxylating reagent N-trifluoromethoxyphthalimide (Phth-OCF3). The reagent was a stable solid and released an OCF3 anion under mild reaction conditions. We demonstrated the application of Phth-OCF3 for the nucleophilic trifluoromethoxylation of various alkyl electrophiles.

Photoredox-Catalyzed and Silane-Mediated Hydrofluoromethylation of Unactivated Alkenes with Fluoroiodomethane in Water.

The first hydrofluoromethylation of unactivated alkenes with fluoroiodomethane and hydrosilanes is developed by merging photoredox catalysis and silane-mediated deiodination processes. The key to the success of this reaction is the use of water as the solvent to enhance the activity of CH2F radical toward unactivated alkenes.

Visible-Light-Induced Nickel-Catalyzed Radical Cross-Couplings to Access α-Aryl-α-trifluoromethyl Alcohols.

A photochemically induced nickel-catalyzed radical cross-coupling of phthalimido trifluoroethanol with aryl bromides to furnish α-aryl-α-trifluoromethyl alcohols is reported. This reaction proceeds via a photoinduced charge transfer of an electron donor-acceptor complex between Hantzsch ester and phthalimido trifluoroethanol, followed by 1,2-hydrogen atom transfer, to generate the α-hydroxytrifluoroethyl radical for the cross-coupling of aryl bromides. No exogenous photocatalysts or stoichiometric metal reductants are required in this mild and operationally simple protocol. Broad substrate compatibility and excellent functional group tolerance are observed.

General Synthesis of N-Trifluoromethyl Compounds with N-Trifluoromethyl Hydroxylamine Reagents.

N-CF3 compounds constitute valuable targets in medicinal chemistry. Extensive studies have been reported for the preparation of N-CF3 compounds through fluorination and trifluoromethylation of N-containing compounds. The development of new synthetic methods from abundant and easily available substrates is highly desirable but still challenging. Herein, we report the design and synthesis of novel N-Cbz- and N-Boc-N-trifluoromethyl hydroxylamine reagents by silver-mediated oxidative trifluoromethylation. These reagents have been successfully applied to the direct incorporation of a NCF3 moiety into the commonly used unsaturated substrates under photoredox catalysis. This protocol enables the efficient and regioselective C-H trifluoromethylamination of various (hetero)arenes, including complex bioactive molecules. Furthermore, a variety of alkenes, dienes, and isonitriles undergo tandem trifluoromethylamination/functionalization delivering structurally diverse N-trifluoromethyl aliphatic and heteroaromatic amines. Notably, previously unknown cyclic N-CF3 compounds including N-CF3 oxazolidinones and oxazolones were conveniently prepared with N-Boc-N-trifluoromethyl hydroxylamine reagents. Furthermore, diversification of the resulting α-trifluoromethylamino ketones afforded the largely underexplored N-alkenyl- and N-alkynyl-N-CF3 compounds.

Photoredox catalyzed C-H trifluoroethylamination of heteroarenes.

The first C-H trifluoroethylamination of heteroarenes with previously unknown N-trifluoroethyl hydroxylamine reagents was achieved under photoredox catalyzed conditions. In the presence of an iridium(III) photoredox catalyst, a variety of heteroarenes, such as indoles, benzofurans, and benzothiophenes, were smoothly converted to the trifluoroethylaminated products in moderate to high yields and with excellent regioselectivity.

Electrochemical Trifluoromethoxylation of (Hetero)aromatics with a Trifluoromethyl Source and Oxygen.

Trifluoromethoxylated aromatics (ArOCF3 ) are valuable structural motifs in the area of drug discovery due to the enhancement of their desired physicochemical properties upon the introduction of the trifluoromethoxy group (CF3 O). Although significant progress has been made recently in the introduction of CF3 O group into aromatics, current methods either require the use of expensive trifluoromethoxylation reagents or require harsh reaction conditions. We present a conceptually new and operationally simple protocol for the direct C-H trifluoromethoxylation of (hetero)aromatics by the combination of the readily available trifluoromethylating reagent and oxygen under electrochemical reaction conditions. This reaction proceeds through the initial generation of CF3 radical followed by conversion to CF3 O radical, addition to (hetero)aromatics and rearomatization. The utility of this electrochemical trifluoromethoxylation is illustrated by the direct incorporation of CF3 O group into a variety of (hetero)aromatics as well as bio-relevant molecules.

Nucleophilic and Radical Heptafluoroisopropoxylation with Redox-Active Reagents.

The heptafluoroisopropyl group (CF(CF3 )2 ) is prevalent in pharmaceuticals and agrichemicals. However, heptafluoroisopropoxylated (OCF(CF3 )2 ) compounds remain largely underexplored, presumably due to the lack of efficient access to these compounds. Herein, we disclose the practical and efficient heptafluoroisopropoxylation reactions through the invention of a series of redox-active N-OCF(CF3 )2 reagents. These reagents were readily prepared from the oxidative heptafluoroisopropylation of hydroxylamines with AgCF(CF3 )2 . The substitutions on the nitrogen atom significantly affected the properties and reactivities of N-OCF(CF3 )2 reagents. Accordingly, two types of N-OCF(CF3 )2 reagents including N-OCF(CF3 )2 phthalimide A and N-OCF(CF3 )2 benzotriazolium salt O' were used as OCF(CF3 )2 anion and radical precursors, respectively. This protocol enables the direct heptafluoroisopropoxylation of a range of substrates, delivering the corresponding products in moderate to excellent yields.

The role of G-protein-coupled receptor kinase 2 in diabetic mechanical hyperalgesia in rats.

BACKGROUND: Previous studies have indicated a negative correlation between GRK2 expression and pain development and transmission. Here, we investigated whether G-protein-coupled receptor kinase 2 (GRK2) was involved in regulating diabetic mechanical hyperalgesia (DMH). METHODS: The adeno-associated viral vectors containing the GRK2 gene (AAV-GRK2) were used to up-regulate GRK2 protein expression. The expression of GRK2 and exchange protein directly activated by cyclic adenosine monophosphate 1 (Epac1) in the dorsal root ganglion (DRG) of lumbar 4-6 was detected via immunoblotting and immunohistochemistry, and the transfection of the GRK2 gene was detected by immunofluorescence. RESULTS: Low levels of GRK2 were able to sustain STZ-induced pain in DMH rats. Intrathecal injection of AAV-GRK2 vector up-regulated GRK2 expression, providing pain rain to rats with DMH. With an increase in DMH duration, there was a decrease in paw withdrawal threshold (PWT) value, aggravating the pain, resulting in a decreasing pattern in GRK2 protein expression over time, whereas Epac1 protein expression showed an opposite trend. CONCLUSION: GRK2 expression regulated DMH progression and is expected to play a role in the development of targeted therapy for DMH. GRK2 and Epac1 expressions play a vital role in maintaining pain in DMH rats.

Chemoselective Hydro(Chloro)pentafluorosulfanylation of Diazo Compounds with Pentafluorosulfanyl Chloride.

Pentafluorosulfanyl chloride (SF5 Cl) is the most prevalent reagent for the incorporation of SF5 group into organic compounds. However, the preparation of SF5 Cl often relies on hazardous reagents and specialized apparatus. Herein, we described a safe and practical synthesis of a bench-stable and easy-to-handle solution of SF5 Cl in n-hexane under gas-reagent-free conditions. The synthetic application of SF5 Cl was demonstrated through the unprecedented reaction with diazo compounds. The chemoselective hydro- and chloropentafluorosulfanylations of α-diazo carbonyl compounds were developed in the presence of K3 PO4 or copper catalyst, respectively. These reactions provide a direct and efficient access to various α-pentafluorosulfanyl carbonyl compounds of high value for potential applications.

Photoredox-Catalyzed Addition of Dibromofluoromethane to Alkenes: Direct Synthesis of 1-Bromo-1-fluoroalkanes.

Reported herein is a direct and efficient route to 1-bromo-1-fluoroalkanes through the reaction of unactivated alkenes with dibromofluoromethane under photoredox catalysis. The key to the success of these addition reactions is the employment of a suitable photoredox catalyst. In particular, hydro- and bromo-bromofluoromethylated products were chemoselectively formed using THF and DMF/H2O as solvents, respectively. Furthermore, the synthetic application of the prepared 1-bromo-1-fluoroalkanes has been demonstrated by their transformation into a variety of fluorine-containing compounds.

Copper and Zinc Copromoted Bromo(chloro)trifluoromethylation of Alkenes and Alkynes with Trifluoromethanesulfonic Anhydride.

The first copper and zinc copromoted trifluoromethylation using trifluoromethanesulfonic anhydride (Tf2O) as a trifluoromethylating reagent has been developed. The reaction of alkenes or alkynes with Tf2O in the presence of CuX2 (X = Br, Cl), Zn powder, and 2,2'-bipyridine affords bromo(chloro)trifluoromethylated products in good yields. CuX2 plays a dual role as the catalyst and halide source, whereas 2,2'-bipyridine acts as both the activation reagent and ligand.

Copper-catalyzed chemoselective C-H functionalization of quinoxalin-2(1H)-ones with hexafluoroisopropanol.

An unexpected three-component reaction of quinoxalin-2(1H)-ones, tert-butyl peroxybenzoate (TBPB), and hexafluoroisopropanol (HFIP) is described. Under CuBr-catalyzed and TBPB-oxidized conditions, a variety of hydroxyhexafluoroisobutylated quinoxalin-2(1H)-ones were formed. Furthermore, the first hexafluoroisopropoxylation of the quinoxalin-2(1H)-ones with HFIP is also demonstrated with Cu2O as the catalyst and PhI(OAc)2 as the oxidant. These new transformations of HFIP furnish previously unknown and potentially useful fluorinated quinoxalin-2(1H)-one derivatives.

Silver-Catalyzed C-H Aryloxydifluoromethylation and Arylthiodifluoromethylation of Heteroarenes.

The oxidative C-H aryloxydifluoromethylation and arylthiodifluoromethylation of heteroaromatic compounds through the decarboxylation of easily accessible aryloxydifluoroacetic acids and arylthiodifluoroacetic acids, respectively, are disclosed. These reactions are promoted by the combination of catalytic AgNO3 and Selectfluor or K2S2O8 to give ArOCF2- and ArSCF2-substituted heteroaromatic compounds in moderate to high yields.

Nickel-Mediated Trifluoromethylation of Phenol Derivatives by Aryl C-O Bond Activation.

The increasing pharmaceutical importance of trifluoromethylarenes has stimulated the development of more efficient trifluoromethylation reactions. Tremendous efforts have focused on copper- and palladium-mediated/catalyzed trifluoromethylation of aryl halides. In contrast, no general method exists for the conversion of widely available inert electrophiles, such as phenol derivatives, into the corresponding trifluoromethylated arenes. Reported herein is a practical nickel-mediated trifluoromethylation of phenol derivatives with readily available trimethyl(trifluoromethyl)silane (TMSCF3 ). The strategy relies on PMe3 -promoted oxidative addition and transmetalation, and CCl3 CN-induced reductive elimination. The broad utility of this transformation has been demonstrated through the direct incorporation of trifluoromethyl into aromatic and heteroaromatic systems, including biorelevant compounds.

Cascade trifluoromethylthiolation and cyclization of N-[(3-aryl)propioloyl]indoles.

A cascade oxidative trifluoromethylthiolation and cyclization of N-[(3-aryl)propioloyl]indoles with AgSCF3 is described. This protocol allows for the synthesis of novel bis(trifluoromethylthiolated) or trifluoromethylthiolated pyrrolo[1,2-a]indol-3-ones in moderate to good yields. Mechanistic investigations indicated that radical processes were probably involved in these transformations.

Oxidative Hydro-, Bromo-, and Chloroheptafluoroisopropylation of Unactivated Alkenes with Heptafluoroisopropyl Silver.

Oxidant-induced three-component hydro-, bromo-, and chloroheptafluoroisopropylation of unactivated alkenes are disclosed. In these reactions, the CF(CF3)2 radical was generated from the oxidation of AgCF(CF3)2. Then the addition of this perfluorinated radical to alkenes, followed by hydrogenation, bromination, or chlorination, gave the corresponding difunctionalized CF(CF3)2-containing products in high yields.

Polymicrobial bacteremia after treatment of transcatheter arterial chemoembolization: A case report.

RATIONALE: Bacteremia caused by polymicrobial infections are rare but dangerous. We report a case of hepatic abscess combined with polymicrobial bacteremia in a 49-year-old male patient after surgery and transcatheter arterial chemoembolization (TACE). PATIENT CONCERNS: The patient was admitted to hospital with metastatic liver cancer for periodic chemotherapy and developed a high fever and tenderness to the liver following surgery and TACE. DIAGNOSIS: Hepatic abscess combined with polymicrobial bacteremia. INTERVENTIONS: The clinician formulated a therapy in accordance with the drug susceptibility test and the empirical drug use for anaerobic bacteria. A comprehensive treatment plan was adopted, on the basis of the combination of nitrazole and imipenem as anti-infection drugs as well as continuous abscess drainage. OUTCOMES: After comprehensive therapy, the patient was ultimately discharged without any residual symptoms. LESSONS: Bloodstream infection caused by multiple bacteria increases the difficulty of anti-infection treatments, leading to poor treatment outcome and high mortality. Therefore, a fast and accurate diagnosis of polymicrobial bacteremia is key for initiation of an effective antimicrobial treatment. Additionally, pre-operative prophylactic antibiotics are advisable when patients have a history of abdominal surgery and are immune-compromised.