Molecular Diversity - A green and efficient one-pot multi-component protocol was developed for the synthesis of some novel dihydrochromeno[4,3-b]pyrrol-3-yl derivatives through the reaction of... 相似文献
Research on Chemical Intermediates - In this research, highly efficient protocols for the production of pyrido[2,3-d:6,5-d′]dipyrimidine and bis(pyrazolyl)methane derivatives using an acid... 相似文献
Ti–Ta and Ti–Ta–xSn shape memory alloys (SMAs) were produced successfully by microwave sintering. Tin element was added to Ti–Ta SMA with three different atomic percentages (0.37, 0.745 and 2.26 at.%). The influences of Sn addition on microstructure, transformation temperatures, mechanical properties, shape memory behaviours, corrosion resistance and bioactivity were investigated. It was found that the morphologies of the modified and unmodified Ti–Ta alloys contain a plate-like and needle-like structure, where the former structure is related to the β phase and the latter related to the α phase. The transformation temperatures of Ms to Mf with and without Sn additions were observed to be in the range of 389.65 to 355 K, while the transformation temperatures of As to Af were found to be in the range of 250.42 to 365.8 K. By increasing the proportion of Sn, the compressive fracture strength and shape memory behaviour were enhanced; however, the corrosion resistance tended to be decreased. Based on the bioactivity results, antibacterial activity was improved with the addition of Sn. In conclusion, the existent results indicate that Ti–30 at.% Ta SMAs may be a convenient alternative to Ni–Ti for certain biomedical applications.
We report a simple process for the synthesis of Fe3O4@SiO2/APTMS (APTMS = 3‐aminopropyltrimethoxysilane) core–shell nanocatalyst support. The new nanocatalyst was prepared by stabilization of Pd(cdha)2 (cdha = bis(2‐chloro‐3,4‐dihydroxyacetophenone)) on the surface of the Fe3O4@SiO2/APTMS support. The structure and composition of this catalyst were characterized using various techniques. An efficient method was developed for the synthesis of a wide variety of biaryl compounds via fluoride‐free Hiyama cross‐coupling reactions of aryl halides with arylsiloxane, with Fe3O4@SiO2/APTMS/Pd(cdha)2 as the catalyst under reaction conditions. This methodology can be performed at 100°C through a simple one‐pot operation using in situ generated palladium nanoparticles. High catalytic activity, quick separation of catalyst from products using an external magnetic field and use of water as green solvent are attributes of this protocol. 相似文献
New, efficient and environmentally adapted synthesis of polysubstituted imidazoles in one‐pot is found. The multicomponent reaction of various aldehydes, benzil, aliphatic and aromatic primary amines and ammonium acetate under solvent‐free condition is explained. The highly efficient role of CrCl3.6H2O as catalyst in this synthesis was shown. By this advantage, several polysubstituted imidazoles as pharmaceutical important molecules can be prepared in high yield and high purity. This method is a very easy and a rapid reaction for the synthesis of imidazole derivatives. The crude products recrystallized to afford the crystalline pure products. Furthermore, catalyst exhibited remarkable reusable activity. 相似文献