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A long-standing challenge in Minisci reactions is achieving the arylation of heteroarenes by oxidative decarboxylation of aromatic carboxylic acids. To address this challenge, the silver-catalyzed intermolecular Minisci reaction of aromatic carboxylic acids was developed. With an inexpensive silver salt as a catalyst, this new reaction enables a variety of aromatic carboxylic acids to undergo decarboxylative coupling with electron-deficient arenes or heteroarenes regardless of the position of the substituents on the aromatic carboxylic acid, thus eliminating the need for ortho-substituted aromatic carboxylic acids, which were a limitation of previously reported methods.

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Background Diabetic cardiomyopathy (DCM) is a common complication of diabetes and is characterized by chronic myocardial inflammation. Mesenchymal stem cell (MSC) infusions have recently been suggested to alleviate myocardial injury and ameliorate cardiac function. However, few studies have focused on the effects of MSCs in DCM. Therefore, we explored the effects of MSC-regulated macrophage polarization on myocardial repair in DCM. Methods A DCM rat model was induced by a high-fat diet and streptozotocin (STZ) administration and infused 4 times with MSCs. Rat blood and heart tissue were analyzed for blood glucose levels, lipid levels, echocardiography, histopathology, macrophage phenotype ratios and inflammatory cytokines, respectively. We mimicked chronic inflammation in vitro by inducing peritoneal macrophages with high glucose and LPS, then cocultured these macrophages with MSCs to explore the specific mechanism of MSCs on macrophage polarization. Results DCM rats exhibited abnormal blood glucose levels and lipid metabolism, cardiac inflammation and dysfunction. MSC infusion ameliorated metabolic abnormalities and preserved cardiac structure and function in DCM rats. Moreover, MSC infusion significantly increased the M2 phenotype macrophages and alleviated cardiac inflammation. Interestingly, this in vitro study revealed that the MSCs pretreated with a COX-2 inhibitor had little effect on M2 macrophage polarization, but this phenomenon could be reversed by adding prostaglandin E2 (PGE2). Conclusions Our results suggested that MSC infusions can protect against cardiac injury in DCM rats. The underlying mechanisms may include MSC-enhanced M2 macrophage polarization via the COX-2-PGE2 pathway.

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Catalytic oxidative C-H bond functionalization reactions that proceed without requiring stoichiometric amounts of external oxidants or pre-functionalized oxidizing reagents could maximize the atom-and step-economy in chemical syntheses. However, such a transformation remains elusive. Here, we report that a photo-driven catalytic process enables decarboxylative C-H trifluoromethylation of (hetero)arenes with trifluoroacetic acid as a trifluoromethyl source in good yields in the presence of an external oxidant in far lower than stoichiometric amounts (for example, 0.2 equivalents of Na 2 S 2 O 8 ) using Rh-modified TiO 2 nanoparticles as a photocatalyst, in which H 2 release is an important driving force for the reaction. Our findings not only provide an approach to accessing valuable decarboxylative C-H trifluoromethylations via activation of abundant but inert trifluoroacetic acid towards oxidative decarboxylation and trifluoromethyl radical formation, but also demonstrate that a photo-driven catalytic process is a promising way to achieve external oxidant-free C-H functionalization reactions.

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A novel chiral microemulsion, which involved the use of chiral alcohols as cosurfactants, was demonstrated for the enantiomeric separation of a number of pharmaceutical drugs in microemulsion electrokinetic chromatography (MEEKC). The chiral alcohols investigated were optically active 2-alkanols, with the alkyl chain length having carbon number ranging from 4 to 7. The data indicated that, except for R-(-)-2-butanol, the use of R-(-)-2-pentanol, R-(-)-2-hexanol or R-(-)-2-heptanol as the chiral cosurfactant resulted in the baseline or partial resolution of most of the test solutes, i.e., (+/-)-norephedrine, (+/-)-ephedrine, DL-nadolol, and DL-propranolol. In addition to the chain length of the chiral 2-alkanols, the effects of other experimental conditions, such as the concentration and chirality of the 2-alkanols, as well as the pH of the run buffer and the oil phase of the microemulsion, on the enantiomeric separation of the test solutes were also investigated. An interesting finding was that the water-immiscible organic solvent (oil core) within the microemulsion droplets appeared to play an important role in the chiral separation mechanism. Also, the importance of hydrogen bonding between the test solutes ((+/-)-ephedrine and related compounds) and the chiral microemulsion was demonstrated, as it was not possible to resolve a pair of enantiomers which lacked a beta-amino proton (i.e., (+/-)-N-methyl ephedrine) under optimized run buffer conditions (e.g., 5.0% R-(-)-2-hexanol, 0.8% n-octane, and 3.5% SDS in 90.7% borate buffer at pH 9.2).