Syntheses, crystal structures, and electrochemical studies of diiron complexes from the reactions of [Et₃NH][(μ-RS) Fe₂(CO)₆(μ-CO)] with isothiocyanates

<div><p>Reactions of [Et₃NH][(μ-MeO₂CCH₂S)Fe₂(CO)₆(μ-CO)] <i>in situ</i> generated from the mixture of MeO₂CCH₂SH, Et₃N, and Fe₃(CO)₁₂ with 2-C₅H₄NNCS, 3-C₅H₄NNCS, and EtNCS in THF, form <b>1</b>, (μ-MeO₂CCH₂S)Fe₂(CO)₅(μ-k²N,S:k²C-2-C₅H₄NNHCS), <b>2</b>, (μ-MeO₂CCH₂S)Fe₂(CO)₆(μ-k²C,S-3-C₅H₄NNHCS), and <b>3</b>, (μ-MeO₂CCH₂S)Fe₂(CO)₆(μ-k²C,S-EtNHCS). Reaction of [Et₃NH][(μ-PhS)Fe₂(CO)₆(μ-CO)] <i>in situ</i> formed from the mixture of PhSH, Et₃N, and Fe₃(CO)₁₂ with EtNCS affords <b>4</b>, (μ-PhS)Fe₂(CO)₆(μ-k²C,S-EtNHCS). Reaction of [Et₃NH][(μ-EtS)Fe₂(CO)₆(μ-CO)] <i>in situ</i> produced from the mixture of EtSH, Et₃N, and Fe₃(CO)₁₂ with EtNCS offers <b>5</b>, (μ-EtS)Fe₂(CO)₆(μ-k²C,S-EtNHCS). All new complexes have been fully characterized by EA, IR, ¹H NMR, and ¹³C NMR and structurally determined by X-ray crystallography. Electrochemical studies on <b>2</b> and <b>5</b> confirm that <b>2</b> shows high H₂-producing activity.</p></div

N‑Heterocyclic Carbene–Copper-Catalyzed Group‑, Site‑, and Enantioselective Allylic Substitution with a Readily Accessible Propargyl(pinacolato)boron Reagent: Utility in Stereoselective Synthesis and Mechanistic Attributes

The first instances of catalytic allylic substitution reactions involving a propargylic nucleophilic component are presented; reactions are facilitated by 5.0 mol % of a catalyst derived from a chiral N-heterocyclic carbene (NHC) and a copper chloride salt. A silyl-containing propargylic organoboron compound, easily prepared in multigram quantities, serves as the reagent. Aryl- and heteroaryl-substituted disubstituted alkenes within allylic phosphates and those with an alkyl or a silyl group can be used. Functional groups typically sensitive to hard nucleophilic reagents are tolerated, particularly in the additions to disubstituted alkenes. Reactions may be performed on the corresponding trisubstituted alkenes, affording quaternary carbon stereogenic centers. Incorporation of the propargylic group is generally favored (vs allenyl addition; 89:11 to >98:2 selectivity); 1,5-enynes can be isolated in 75–90% yield, 87:13 to >98:2 S_N2′/S_N2 (branched/linear) selectivity and 83:17–99:1 enantiomeric ratio. Utility is showcased by conversion of the alkynyl group to other useful functional units (e.g., homoallenyl and <i>Z</i>-homoalkenyl iodide), direct access to which by other enantioselective protocols would otherwise entail longer routes. Application to stereoselective synthesis of the acyclic portion of antifungal agent plakinic acid A, containing two remotely positioned stereogenic centers, by sequential use of two different NHC–Cu-catalyzed enantioselective allylic substitution (EAS) reactions further highlights utility. Mechanistic investigations (density functional theory calculations and deuterium labeling) point to a bridging function for an alkali metal cation connecting the sulfonate anion and a substrate’s phosphate group to form the branched propargyl addition products as the dominant isomers via Cu­(III) π-allyl intermediate complexes

Syntheses, crystal structures, and electrochemical studies of Fe₂(CO)₆(μ-PPh₂)(μ-L) (L = OH, OPPh₂, PPh₂)

<div><p>Reaction of Fe₃(CO)₁₂ and Ph₂PH in the presence of Et₃N in THF at 0 °C immediately forms Fe₂(CO)₆(μ-PPh₂)(μ-OH) (<b>1</b>), Fe₂(CO)₆(μ-PPh₂)(μ-k²O,P-OPPh₂) (<b>2</b>), and Fe₂(CO)₆(μ-PPh₂)₂ (<b>3</b>) in yields of 25, 14, and 19%, respectively. Experiments confirm that Et₃N shortens the reaction time. The absence of O₂ hinders the formation of <b>2</b>. The presence of H₂O can increase the yield of <b>1</b>. Their structures have been determined by X-ray crystallography and the complexes have been completely characterized by EA, IR, and ¹H, ¹³C, ³¹P NMR. Electrochemical studies reveal that they exhibit catalytic H₂-producing activities.</p></div

N‑Heterocyclic Carbene–Copper-Catalyzed Group‑, Site‑, and Enantioselective Allylic Substitution with a Readily Accessible Propargyl(pinacolato)boron Reagent: Utility in Stereoselective Synthesis and Mechanistic Attributes

The first instances of catalytic allylic substitution reactions involving a propargylic nucleophilic component are presented; reactions are facilitated by 5.0 mol % of a catalyst derived from a chiral N-heterocyclic carbene (NHC) and a copper chloride salt. A silyl-containing propargylic organoboron compound, easily prepared in multigram quantities, serves as the reagent. Aryl- and heteroaryl-substituted disubstituted alkenes within allylic phosphates and those with an alkyl or a silyl group can be used. Functional groups typically sensitive to hard nucleophilic reagents are tolerated, particularly in the additions to disubstituted alkenes. Reactions may be performed on the corresponding trisubstituted alkenes, affording quaternary carbon stereogenic centers. Incorporation of the propargylic group is generally favored (vs allenyl addition; 89:11 to >98:2 selectivity); 1,5-enynes can be isolated in 75–90% yield, 87:13 to >98:2 S_N2′/S_N2 (branched/linear) selectivity and 83:17–99:1 enantiomeric ratio. Utility is showcased by conversion of the alkynyl group to other useful functional units (e.g., homoallenyl and <i>Z</i>-homoalkenyl iodide), direct access to which by other enantioselective protocols would otherwise entail longer routes. Application to stereoselective synthesis of the acyclic portion of antifungal agent plakinic acid A, containing two remotely positioned stereogenic centers, by sequential use of two different NHC–Cu-catalyzed enantioselective allylic substitution (EAS) reactions further highlights utility. Mechanistic investigations (density functional theory calculations and deuterium labeling) point to a bridging function for an alkali metal cation connecting the sulfonate anion and a substrate’s phosphate group to form the branched propargyl addition products as the dominant isomers via Cu­(III) π-allyl intermediate complexes

Data_Sheet_3_The lncRNA HCG4 regulates the RIG-I-mediated IFN production to suppress H1N1 swine influenza virus replication.XLSX

Influenza A virus (IAV) non-structural protein 1 (NS1) is a virulence factor that allows the virus to replicate efficiently by suppressing host innate immune responses. Previously, we demonstrated that the serine (S) at position 42 of NS1 in H1N1 swine influenza virus (SIV) is a critical residue in interferon (IFN) resistance, thus facilitating viral infections. Here, by lncRNA-seq, a total of 153 differentially expressed lncRNAs were identified, and the lncRNA HCG4 was selected due to its significantly higher expression after infection with the NS1 S42P mutant virus. Overexpression of HCG4 enhanced IFN-β production and suppressed SIV infection, highlighting the potential antiviral activity of HCG4 against SIV. Further investigation suggested that HCG4 served as a positive feedback mediator for RIG-I signaling. It alleviated the inhibitory effect on RIG-I K63-linked ubiquitination by NS1 protein, thereby resulting in an increase in RIG-I-mediated IFN production. Taken together, our findings demonstrate that HCG4 modulates the innate immune response to SIV infection through K63-linked RIG-I ubiquitination, providing insights into the role of lncRNAs in controlling viral infections.</p

Data_Sheet_2_The lncRNA HCG4 regulates the RIG-I-mediated IFN production to suppress H1N1 swine influenza virus replication.XLSX

Influenza A virus (IAV) non-structural protein 1 (NS1) is a virulence factor that allows the virus to replicate efficiently by suppressing host innate immune responses. Previously, we demonstrated that the serine (S) at position 42 of NS1 in H1N1 swine influenza virus (SIV) is a critical residue in interferon (IFN) resistance, thus facilitating viral infections. Here, by lncRNA-seq, a total of 153 differentially expressed lncRNAs were identified, and the lncRNA HCG4 was selected due to its significantly higher expression after infection with the NS1 S42P mutant virus. Overexpression of HCG4 enhanced IFN-β production and suppressed SIV infection, highlighting the potential antiviral activity of HCG4 against SIV. Further investigation suggested that HCG4 served as a positive feedback mediator for RIG-I signaling. It alleviated the inhibitory effect on RIG-I K63-linked ubiquitination by NS1 protein, thereby resulting in an increase in RIG-I-mediated IFN production. Taken together, our findings demonstrate that HCG4 modulates the innate immune response to SIV infection through K63-linked RIG-I ubiquitination, providing insights into the role of lncRNAs in controlling viral infections.</p

Additional file 1 of Mortality and disability risk among older adults unable to complete grip strength and physical performance tests: a population-based cohort study from China

Supplementary Material

Data_Sheet_1_The lncRNA HCG4 regulates the RIG-I-mediated IFN production to suppress H1N1 swine influenza virus replication.XLS

Influenza A virus (IAV) non-structural protein 1 (NS1) is a virulence factor that allows the virus to replicate efficiently by suppressing host innate immune responses. Previously, we demonstrated that the serine (S) at position 42 of NS1 in H1N1 swine influenza virus (SIV) is a critical residue in interferon (IFN) resistance, thus facilitating viral infections. Here, by lncRNA-seq, a total of 153 differentially expressed lncRNAs were identified, and the lncRNA HCG4 was selected due to its significantly higher expression after infection with the NS1 S42P mutant virus. Overexpression of HCG4 enhanced IFN-β production and suppressed SIV infection, highlighting the potential antiviral activity of HCG4 against SIV. Further investigation suggested that HCG4 served as a positive feedback mediator for RIG-I signaling. It alleviated the inhibitory effect on RIG-I K63-linked ubiquitination by NS1 protein, thereby resulting in an increase in RIG-I-mediated IFN production. Taken together, our findings demonstrate that HCG4 modulates the innate immune response to SIV infection through K63-linked RIG-I ubiquitination, providing insights into the role of lncRNAs in controlling viral infections.</p

Photodegradation of MO by Cu(II)-tartaric acid with different pre-treatments.

<p>Degradation conditions: 0.15 mmol/L MO, 1 mmol/L Cu(II) and 10 mmol/L tartaric acid under the full light of a 300 W medium pressure Hg lamp at pH 4 and 25°C.</p

Rapid Photodegradation of Methyl Orange (MO) Assisted with Cu(II) and Tartaric Acid

<div><p>Cu(II) and organic carboxylic acids, existing extensively in soil and aquatic environments, can form complexes that may play an important role in the photodegradation of organic contaminants. In this paper, the catalytic role of Cu(II) in the removal of methyl orange (MO) in the presence of tartaric acid with light was investigated through batch experiments. The results demonstrate that the introduction of Cu(II) could markedly enhance the photodegradation of MO. In addition, high initial concentrations of Cu(II) and tartaric acid benefited the decomposition of MO. The most rapid removal of MO assisted by Cu(II) was achieved at pH 3. The formation of Cu(II)-tartaric acid complexes was assumed to be the key factor, generating hydroxyl radicals (•OH) and other oxidizing free radicals under irradiation through a ligand-to-metal charge-transfer pathway that was responsible for the efficient degradation of MO. Some intermediates in the reaction system were also detected to support this reaction mechanism.</p></div