Reactions of N‑Heterocyclic Carbene Boranes with 5‑Diazo-2,2-dimethyl-1,3-dioxane-4,6-dione: Synthesis of Mono- and Bis-hydrazonyl NHC-Boranes

N-Heterocyclic carbene boranes (NHC-boranes) react with 5-diazo-2,2-dimethyl-1,3-dioxane-4,6-dione at 40 °C in dichloromethane to provide NHC-boryl hydrazone derivatives of 2,2-dimethyl-1,3-dioxane-4,6-dione. These hydrazones disproportionate to bis-hydrazones on treatment with diiodine in dichloromethane at room temperature. The mono- and bis-hydrazones are yellow solids that are stable to chromatography and storage

Reactions of N‑Heterocyclic Carbene Boranes with 5‑Diazo-2,2-dimethyl-1,3-dioxane-4,6-dione: Synthesis of Mono- and Bis-hydrazonyl NHC-Boranes

N-Heterocyclic carbene boranes (NHC-boranes) react with 5-diazo-2,2-dimethyl-1,3-dioxane-4,6-dione at 40 °C in dichloromethane to provide NHC-boryl hydrazone derivatives of 2,2-dimethyl-1,3-dioxane-4,6-dione. These hydrazones disproportionate to bis-hydrazones on treatment with diiodine in dichloromethane at room temperature. The mono- and bis-hydrazones are yellow solids that are stable to chromatography and storage

High Catalytic Activity in the Phenol Hydroxylation of Magnetically Separable CuFe₂O₄–Reduced Graphene Oxide

We reported a highly active CuFe₂O₄ catalyst modified with reduced graphene oxide (CuFe₂O₄–RGO) by a solvothermal method. The composite catalyst was fully characterized by FTIR, XRD, Raman, TEM, and XPS, which demonstrated that the CuFe₂O₄ nanoparticles (NPs) with a diameter of approximately 17.8 nm were densely and compactly deposited on the reduced graphene oxide (RGO) sheets. The as-prepared CuFe₂O₄–RGO composites were used to catalyze phenol hydroxylation for the first time, which exhibited great catalytic activity. The conversion rate of phenol to dihydroxybenzenes reached 35.5% with a selectivity of 95.2% obtained, which is much higher than for reported systems (25.0%). The catalytic activity remained high after six cycles. More importantly, the catalyst can be easily recovered due to its magnetic separability and the organic solvent-free nature of the phenol hydroxylation process. A possible mechanism in phenol hydroxylation by H₂O₂ over CuFe₂O₄–RGO₂₀ catalyst was also proposed

Highly Chemoselective and Enantioselective Catalytic Oxidation of Heteroaromatic Sulfides via High-Valent Manganese(IV)–Oxo Cation Radical Oxidizing Intermediates

A manganese complex with a porphyrin-like ligand that catalyzes the highly chemoselective and enantioselective oxidation of heteroaromatic sulfides, including imidazole, benzimidazole, indole, pyridine, pyrimidine, pyrazine, <i>sym</i>-triazine, thiophene, thiazole, benzothiazole, and benzoxazole, with hydrogen peroxide is described, furnishing the corresponding sulfoxides in good to excellent yields and enantioselectivities (up to 90% yield and up to >99% ee) within a short reaction time (0.5 h). The practical utility of the method has been demonstrated in the gram-scale synthesis of chiral sulfoxide. Mechanistic studies, performed with ¹⁸O-labeled water (H₂¹⁸O), hydrogen peroxide (H₂¹⁸O₂), and cumyl hydroperoxide, reveal that a high-valent manganese–oxo species is generated as the oxygen atom delivering agent via carboxylic acid assisted heterolysis of O–O bonds. Density functional theory (DFT) calculations were also carried out to give further insight into the mechanism of manganese-catalyzed sulfoxidation. On the basis of the theoretical study, the coupled high-valent manganese­(IV)–oxo cation radical species, which bears obvious similarities with that of reactive intermediates in the catalytic oxygenation reactions based on the cytochrome P450 and metalloporphyrin models, has been proposed as the reactive oxidant in the non-heme manganese catalyst system

Asymmetric Epoxidation of Alkenes Catalyzed by a Porphyrin-Inspired Manganese Complex

A novel strategy for catalytic asymmetric epoxidation of a wide variety of olefins by a porphyrin-inspired chiral manganese complex using H₂O₂ as a terminal oxidant in excellent yield with up to greater than 99% ee has been successfully developed

Exhaustive Hydrodefluorination or Deuterodefluorination of Trifluoromethylarenes via Metal-Free Photoredox Catalysis

Perfluoroalkyl compounds are persistent environmental pollutants due to their chemical and thermal stability. Hydrodefluorination is one of the most promising strategies for the disposal of fluorine-containing compounds, which has attracted much attention from a broad spectrum of scientific communities. Herein, we disclose a metal-free, visible-light-promoted protocol for the exhaustive hydrodefluorination of a wide variety of trifluoromethylarenes with up to 95% yields. Moreover, methyl-d3 groups can be obtained via deuterium water with a D ratio of up to 94%

Hepatic apoA5 and PPARα mRNA and protein expressions in rats.

<p>The mRNA and protein levels of hepatic apoA5 and PPARα in rats were detected by RT-qPCR and Western blot analysis respectively: (A and B) ApoA5 mRNA and protein- Compared with control group, a significant reduction of apoA5 mRNA and protein was observed in fructose group. However, the two treatments effectively ameliorated fructose-induced down-regulation of apoA5 expressions, whereas this effect was more considerable in XZK group. (C and D) PPARα mRNA and protein- Similar findings of hepatic PPARα expressions were obtained, i.e. the two treatments attenuated fructose-induced down-regulation of hepatic PPARα expressions but this effect was more remarkable in XZK group. E ApoA5 and PPARα protein results by Western blot analysis. *^{, #, &} Values were significantly different from control, fructose, and statin groups, respectively (P < 0.05). ApoA5, apolipoprotein A5; PPARα, peroxisome proliferator-activated receptor α; XZK, Xuezhikang.</p

LDL-R, TG, apoA5 and PPARα in HepG2 cells.

<p>(A-B) LDL-R protein expressions: Two protein bands of LDL-R were exhibited including its precursor (120 kDa) and mature (160 kDa) forms. No significant difference of LDL-R expressions was indicated between the two treatments. (C) TG contents: The two agents effectively ameliorated fructose-induced TG elevation but this effect was more considerable in XZK group. Interestingly, PPARα down-regulation by shRNA effectively inhibited XZK-induced hypotriglyceridemic actions. (D-H) mRNA and protein of ApoA5 and PPARα: The two agents remarkably ameliorated fructose-induced down-regulation of apoA5 and PPARα mRNA and protein, whereas these effects were more significant in XZK group than statin group. However, PPARα knockdown eliminated these above effects of XZK. *^{, #, &, §} Values were significantly different from control, fructose, statin and XZK group, respectively (P < 0.05). LDL-R, low density lipoprotein receptor; TG, triglyceride; ApoA5, apolipoprotein A5; PPARα, peroxisome proliferator-activated receptor α; XZK, Xuezhikang.</p

Asymmetric Epoxidation of Olefins with Hydrogen Peroxide by an in Situ-Formed Manganese Complex

Asymmetric epoxidation of a variety of cis, trans, terminal, and trisubstituted olefins in excellent yields (up to 94%) and enantioselectivities (>99% ee) by an in situ-formed manganese complex using H₂O₂ has been developed. A relationship between the hydrophobicity of the catalyst imposed by ligand and the catalytic activity has been observed. The influence of the amount and identity of the acid additive was examined, and improved enantioselectivities were achieved through the use of a catalytic amount of a carboxylic acid additive

Oligonucleotide sequences of primers and shRNA targeting human PPARα gene.

<p>Oligonucleotide sequences of primers and shRNA targeting human PPARα gene.</p