MnCO3-Catalyzed Transesterification of Alcohols with Dimethyl Carbonate Under Mild Conditions
摘要:
Dimethyl carbonate (DMC) is a valuable green reagent with versatile and tunable chemical reactivity and can be used as a raw material for transesterification of alcohols. Herein, MnCO3 was found to be an efficient heterogeneous catalyst for transesterification of various alcohols with DMC and gave desired products under mild conditions. The MnCO3 catalysts were fully characterized by XRD, BET, SEM, TEM, FT-IR and NH3-TPD. The analysis results indicated that MnCO3 calcined at 300 degrees C has significantly enhanced surface area and abundant weak acid sites, which contributed to the superior catalytic performance in the transesterification. Furthermore, deactivation of catalyst resulted from the change of crystal structure and the decrease of weak acid sites. This research expands the potential application for DMC in green chemistry.[GRAPHICS].
Substrate switchable Suzuki–Miyaura coupling for benzyl ester <i>vs.</i> benzyl halide
作者:Masato Ohsumi、Akitaka Ito、Nagatoshi Nishiwaki
DOI:10.1039/c8ra07841f
日期:——
developed to accomplish the substrate switchable Suzuki–Miyaura coupling of benzyl derivatives and arylboronic acid derivatives. Under conditions for esters, benzyl esters such as carbonates and acetates reacted with arylboronic acids to afford the corresponding diarylmethanes. However, the benzyl halides did not react under the same conditions. On the other hand, benzyl halides such as bromides and