Nitrogen heterocycles are of great medicinal importance, and the construction of nitrogen heterocyclic scaffolds has been one of the focuses in synthetic organic chemistry.

In order to decrease the disadvantageous effect of ultraviolet light to asphalt, nano-scaled TiO2 was selected as modifier to modify asphalt. The photooxidation properties of the modified asphalt were examined in a home-made ultraviolet radiation environment box. By comparing the before and after performance indexes of asphalt, the anti-photooxidation aging property of modified asphalt and the blank asphalt were studied. And the results showed that the sample of 5% TiO2 modified asphalt possesses more stable ductility and smaller softening point changing ratio.TiO2 doping can actively enhance the photooxidation properties of asphalt and TiO2 modified asphalt is capable of resisting photooxidation aging.

α-Amino acid and peptide derivatives are important in synthetic organic chemistry and medicinal chemistry, which attract many chemists to develop new methods for synthesis of them. Palladium-catalyzed sp3 C-H activation/functionalization...

To make nano calcium carbonate as the modifier, firstly the best proportion of nano calcium carbonate is determined as 6% by comparing the influences of different proportions of nano calcium carbonate to the indexes of asphalt. Then the influence of mixing with nano calcium carbonate to the performance of asphalt concrete AC-13 has been studied. Tests show that, the mixing of 6% nano calcium carbonate has improved the dynamic stability of asphalt concrete AC-13 from 991 times/mm to 1269 times/mm; the residual stability from 0.87 to 0.94. This indicates that after mixing with nano calcium carbonate, both the high temperature performance and water stability of asphalt concrete have been improved.

This feature article introduces the progress of transition metal-catalyzed stereoselective sp2 and sp3 C-H activation and silylation to synthesize chiral organosilicon compounds, the asymmetric C-H silylation includes intramolecular cyclizing silylation...