Direct Difluoromethylation of Aryl Halides via Base Metal Catalysis at Room Temperature

A stable and isolable difluoro­methyl zinc reagent has been prepared through the reaction of ICF₂H with diethyl zinc and DMPU. This new zinc reagent is a free-flowing solid and can be used in combination with a nickel catalyst to difluoro­methylate aryl iodides, bromides, and triflates at room temperature. Such mild conditions for the catalytic difluoro­methylation of these substrates are unprecedented

Stepwise Conversion of a Platinum Dimethyl Complex to a Perfluorometallacyclobutane Derivative

In this report, we have demonstrated proof-in-principle that simple dimethyl metal complexes could be used to generate perfluorometallacyclobutane derivatives. With the new methodology, we have more than doubled the number of known perfluorometallacyclobutanes in the literature. We have also structurally characterized three platinum perfluorometallacyclobutanes and have described a unique transformation whereby one [Pt­(C₃F₆)] functionality is converted to [Pt­(C₃F₄O₂)]. The new methodology to prepare perfluorometallacyclobutanes also avoids the use of tetrafluoroethylene, which is becoming increasingly difficult to purchase due to the explosion hazards associated with its use

Effect of PEO-PPO-ph-PPO-PEO and PPO-PEO-ph-PEO-PPO on the Rheological and EOR Properties of Polymer Solutions

The rheological properties of partially hydrolyzed polyacrylamide (HPAM) and PEO-PPO-ph-PPO-PEO (BPE) or PPO-PEO-ph-PEO-PPO (BEP) block polyether solutions are investigated here. Another hydrophobically associating polymer (HMPAM) is chosen as a contrast. The rheological results show that the elastic modulus (G′) and viscous modulus (G″) of HPAM/BPE and HPAM/BEP solutions first increase then decrease, while the viscosities of HMPAM/BPE and HMPAM/BEP solutions decrease with the increase of block polyether concentration. The HPAM/BPE solution has a larger viscosity than HPAM/BEP, while the HMPAM/BPE solution has a lower viscosity than HMPAM/BEP. The polymer solutions containing BEP have larger G′ and G″ values than the solutions with BPE. Furthermore, the block polyethers reduce the sensitivity of viscosity to temperature. BEP is more effective to stabilize the viscoelastic property and improve the temperature resistance than BPE in HMPAM system. BEP has a better property to enhance the salt tolerance of the polymer solution than BPE. Moreover, the enhanced oil recovery (EOR) experiments show that HPAM/block polyether mixed solution has a larger oil recovery than HPAM, and HPAM/BEP system has a larger enhanced effect than HPAM/BPE solution

Aggregation Behaviors of PEO-PPO-ph-PPO-PEO and PPO-PEO-ph-PEO-PPO at an Air/Water Interface: Experimental Study and Molecular Dynamics Simulation

The block polyethers PEO-PPO-ph-PPO-PEO (BPE) and PPO-PEO-ph-PEO-PPO (BEP) are synthesized by anionic polymerization using bisphenol A as initiator. Compared with Pluronic P123, the aggregation behaviors of BPE and BEP at an air/water interface are investigated by the surface tension and dilational viscoelasticity. The molecular construction can influence the efficiency and effectiveness of block polyethers in decreasing surface tension. BPE has the most efficient ability to decrease surface tension of water among the three block polyethers. The maximum surface excess concentration (Γ_max) of BPE is larger than that of BEP or P123. Moreover, the dilational modulus of BPE is almost the same as that of P123, but much larger than that of BEP. The molecular dynamics simulation provides the conformational variations of block polyethers at the air/water interface

Palladium-Catalyzed Addition of Potassium Aryltrifluoroborates to Aliphatic Nitriles: Synthesis of Alkyl Aryl Ketones, Diketone Compounds, and 2‑Arylbenzo[<i>b</i>]furans

A palladium-catalyzed addition of potassium aryltrifluoroborates to aliphatic nitriles has been developed, leading to a wide range of alkyl aryl ketones with moderate to excellent yields. Moreover, several dinitriles (e.g., malononitrile, glutaronitrile, and adiponitrile) were applicable to this process for the construction of 1,3-, 1,5-, or 1,6-dicarbonyl compounds. The scope of the developed approach is successfully explored toward the one-step synthesis of 2-arylbenzo­[<i>b</i>]­furans via sequential addition and intramolecular annulation reactions. The methodology accepted a wide range of substrates and is applicable to library synthesis

RORγt Modulates Macrophage Recruitment during a Hydrocarbon Oil-Induced Inflammation

<div><p>Hydrocarbon oils are often utilized as adjuvants in vaccines. In response to naturally occurring hydrocarbon oils, inflammation is initiated and persists with the continuous recruitment of immune cells such as macrophages and neutrophils. However, the mechanism underlying the chronic inflammation in response to hydrocarbon oils is not fully defined. In this study, we revealed an essential role of retinoid-related orphan receptor gamma t (RORγt) in sustaining the recruitment of macrophages following pristane treatment. RORγt absence resulted in the incompetent formation of mesenteric oil granulomas which may associate to a reduction in the migration of macrophages into the mesentery during pristane-induced inflammation. This is at least partially dependent on the expression of the monocyte chemoattractant protein-1 (MCP-1) in the mesentery and the decrease in the macrophage reservoir in the spleen. However, the absence of RORγt had no impact on the recruitment of neutrophils to the mesentery after pristane treatment. Our data uncovered an important role of RORγt in the recruitment of macrophages during hydrocarbon oil-induced chronic inflammation.</p></div

RORγt controls pristane-induced formation of oil granulomas on the mesentery.

<p>(A–B) The mesenteric tissues associated with the gut were collected from naïve mice or pristane-treated C57BL/6 mice (3 weeks) and photographed. SG, serosal granulomas; MG, mesenteric granulomas. (C–D) Images shown represent the mesenteric tissues associated with the gut in either naïve or pristane-treated (3 weeks) RORγt^−/− mice. (E) SG was quantitated in wild type (WT) controls and RORγt^−/− mice after pristane treatment. (F), Analysis of cellularity of whole mesenteric tissue in WT and RORγt^−/− mice. (G-I), The number of B cells (B220⁺), macrophages (CD11b⁺Gr1^low) or neutrophils (CD11b⁺Gr1^hi) in whole mesenteric tissue was summarized. Data show the average ± SD of three mice, representing three independent experiments. *<i>p</i><0.05, **<i>p</i><0.01, compared with the WT group.</p

RORγt deficiency alters the expression of chemokines by mesenteric cells during pristane-induced inflammation.

<p>Levels of mRNA of indicated chemokines in mesenteric cells from naïve or pristane-injected WT and RORγt^−/− mice were measured by quantitative PCR. Data show the average ± SD of three samples, representing three independent experiments. *<i>p</i><0.05, compared with the control group.</p

RORγt deficiency reduces splenic macrophage expansion during pristane-induced inflammation.

<p>Total cells (A), macrophages (B) and neutrophils (C) in the spleens of naïve or pristane-treated WT or RORγt^−/− mice were numerated. Data show the average ± SD of three samples, representing three independent experiments. *<i>p</i><0.05, compared with the control group.</p

π‑Extended Isoindigo-Based Derivative: A Promising Electron-Deficient Building Block for Polymer Semiconductors

The exploration of novel electron-deficient building blocks is a key task for developing high-performance polymer semiconductors in organic thin-film transistors. In view of the situation of the lack of strong electron-deficient building blocks, we designed two novel π-extended isoindigo-based electron-deficient building blocks, IVI and F₄IVI. Owing to the strong electron-deficient nature and the extended π-conjugated system of the two acceptor units, their copolymers, PIVI2T and PF₄IVI2T, containing 2,2′-bithiophene donor units, are endowed with deep-lying highest occupied molecular orbital (HOMO)/lowest unoccupied molecular orbital (LUMO) energy levels and strong intermolecular interactions. In comparison to PIVI2T, the fluorinated PF₄IVI2T exhibits stronger intra- and intermolecular interactions, lower HOMO/LUMO energy levels up to −5.74/–4.17 eV, and more ordered molecular packing with a smaller π–π stacking distance of up to 3.53 Å, resulting in an excellent ambipolar transporting behavior and a promising application in logic circuits for PF₄IVI2T in ambient with hole and electron mobilities of up to 1.03 and 1.82 cm² V^–1 s^–1, respectively. The results reveal that F₄IVI is a promising and strong electron-deficient building unit to construct high-performance semiconducting polymers, which provides an insight into the structure–property relationships for the exploration and molecular engineering of excellent electron-deficient building blocks in the field of organic electronics