Synthesis of Primary and Secondary Alkylboronates through Site-Selective C(sp³)–H Activation with Silica-Supported Monophosphine–Ir Catalysts

The site-selective activation and borylation of unactivated C­(sp³)–H bonds in 2-alkylpyridines to form primary and secondary alkylboronates was achieved using silica-supported monophosphine–Ir catalysts. This borylation occurs selectively at C–H bonds located γ to the pyridine nitrogen atom. The site-selectivity of this reaction suggests that the C–H bond cleavage occurs with the assistance of a proximity effect due to N-to-Ir coordination

Elevated Alpha 1(I) to Alpha 2(I) Collagen Ratio in Dermal Fibroblasts Possibly Contributes to Fibrosis in Systemic Sclerosis

Systemic sclerosis (SSc) is characterized by excessive collagen deposition in the skin and internal organs. Activated fibroblasts are the key effector cells for the overproduction of type I collagen, which comprises the α1(I) and α2(I) chains encoded by COL1A1 and COL1A2, respectively. In this study, we examined the expression patterns of α1(I) and α2(I) collagen in SSc fibroblasts, as well as their co-regulation with each other. The relative expression ratio of COL1A1 to COL1A2 in SSc fibroblasts was significantly higher than that in control fibroblasts. The same result was observed for type I collagen protein levels, indicating that α2(I) collagen is more elevated than α2(I) collagen. Inhibition or overexpression of α1(I) collagen in control fibroblasts affected the α2(I) collagen levels, suggesting that α1(I) collagen might act as an upstream regulator of α2(I) collagen. The local injection of COL1A1 small interfering RNA in a bleomycin-induced SSc mouse model was found to attenuate skin fibrosis. Overall, our data indicate that α2(I) collagen is a potent regulator of type I collagen in SSc; further investigations of the overall regulatory mechanisms of type I collagen may help understand the aberrant collagen metabolism in SSc

Rh-Catalyzed Borylation of N‑Adjacent C(sp³)–H Bonds with a Silica-Supported Triarylphosphine Ligand

Direct C­(sp³)–H borylation of amides, ureas, and 2-aminopyridine derivatives at the position α to the N atom, which gives the corresponding α-aminoalkylboronates, has been achieved with a heterogeneous catalyst system consisting of [Rh­(OMe)­(cod)]₂ and a silica-supported triarylphosphine ligand (Silica-TRIP) that features an immobilized triptycene-type cage structure with a bridgehead P atom. The reaction occurs not only at terminal C–H bonds but also at internal secondary C–H bonds under mild reaction conditions (25–100 °C, 0.1–0.5 mol % Rh)

Silica-Supported Triptycene-Type Phosphine. Synthesis, Characterization, and Application to Pd-Catalyzed Suzuki–Miyaura Cross-Coupling of Chloroarenes

A silica-supported triptycene-type phosphine, Silica-TRIP, comprising a 9-phospha-10-silatriptycene (TRIP) and silica gel as a P-coordination center and a solid support, respectively, was synthesized and structurally characterized by nitrogen absorption measurements and solid-state CP/MAS NMR spectroscopy. Silica-TRIP exhibited a mono-P-ligating feature toward a Pd­(II) complex, resulting in selective formation of a 1/1 Pd–P species even with an excess amount of the ligand. As a result, Silica-TRIP enabled Pd-catalyzed Suzuki–Miyaura cross-coupling reactions of chloroarenes under mild conditions, regardless of the moderate electron-donating nature of the triarylphosphine-based ligand

Clinical characteristics of HIV-1-infected patients with high levels of plasma interferon-γ: a multicenter observational study

Abstract Background Circulating interferon-γ (IFN-γ) concentration may be sustained at a high level regardless of the initiation of antiretroviral therapy (ART) in some patients with HIV-1 infection. In the present study, we examined the clinical characteristics of HIV-1-infected patients with high levels of plasma IFN-γ. Methods The study subjects were patients infected with HIV-1 who were either naïve to ART with CD4+ cell count > 200 cells/μL (n = 12), or had achieved viral suppression after ART for over a year (n = 188). The levels of plasma IFN-γ and interleukin-6 (IL-6) were measured by the enzyme-linked immunosorbent assay. Patients were divided into high IFN-γ and low IFN-γ groups based on a cutoff level of 5 pg/mL. Results The high IFN-γ group included 41 patients (21%). Compared to the patients on ART with low IFN-γ levels, those on ART in the high IFN-γ group were more likely to be younger than 50 years of age (P = 0.0051) and less likely to have dyslipidemia (P = 0.0476) or to be on a protease inhibitor (P = 0.0449). There was no significant difference between groups in the median increase of CD4+ cell counts from the initiation of ART for up to 3 years. However, after 4 years, the increase in CD4+ cell counts was significantly lower in the high IFN-γ group compared with that in the low IFN-γ group. There were no such significant differences between patients with low and high (> 2 pg/mL) levels of plasma IL-6. Conclusion We concluded that HIV-1-infected patients with high levels of circulating IFN-γ did not have a higher rate of comorbidities related to immune activation. However, they exhibited lower CD4+ cell count recovery after 4 years of being on ART. This deficit could be a consequence of persistent immune activation