Asymmetric Defluoroallylation of 4-Trifluoromethylpyridines Enabled by Umpolung C-F Bond Activation.

Carbon-fluorine bond activation of the trifluoromethyl group represents an important approach to fluorine-containing molecules. While selective defluorinative functionalization reactions of CF -containing substrates have been achieved by invoking difluorocarbocation, difluorocarboradical, or difluoroorganometallic species as the key intermediates, the transformations via fluorocarbanion mechanism only achieved limited success. Furthermore, the enantioselective defluorinative transformation of the CF group remained a formidable challenge.

An umpolung approach to the hydroboration of pyridines: a novel and efficient synthesis of -H 1,4-dihydropyridines.

The first inverse hydroboration of pyridine with a diboron(4) compound and a proton source has been realized under simple basic and catalyst-free conditions. This process consists of a formal boryl anion addition to pyridine, which produces an -boryl pyridyl anion complex, and the subsequent protonation of the anion complex. This process enables a simple and efficient method for the synthesis of multi-substituted -H 1,4-dihydropyridine (1,4-DHP) derivatives that are difficult to prepare using established methods.

Ti-Ge binary alloy system developed as potential dental materials.

As-cast Ti-xGe (x = 2, 5, 10, 20 wt %) binary alloys were produced in this work, and various experiments were carried out to investigate the microstructure, mechanical properties, in vitro electrochemical and immersion corrosion behaviors as well as cytotoxicity with as-cast pure Ti as control, aiming to study the feasibility of Ti-xGe alloy system as potential dental materials. The microstructure of Ti-xGe alloys changes from single α-Ti phase to α-Ti + Ti(5)Ge(3) precipitation phase with the increase of Ge content. Mechanical tests show that Ti-5Ge alloy has the best comprehensive mechanical properties.

[The expression of migration inhibitory factor in peripheral blood mononuclear cell and its correlation with disease activity in systemic lupus erythematosus].

Objective: To investigate the change of macrophage migration inhibitory factor (MIF) mRNA expression in peripheral blood mononuclear cell (PBMC) and serum MIF and its correlation with disease active index in patients with systemic lupus erythematosus (SLE).

Methods: MIF mRNA expression of PBMC and serum MIF in patients with active and inactive SLE was measured by reverse transcriptase-polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. The correlations of serum MIF with SLE disease active index, serum ds-DNA antibody, ANA, C3, C4 and IgG were examined.