Photopromoted carbonylation of bromohydrocarbon catalyzed by cobalt complexes can be carried out under ambient conditions in CH3OH/DMF.It is found that DMF can be decomposed into CO under irradiation and thus can be used as a CO source for the photopromoted carbonylationof bromohydrocarbon,which has been proved by isotope experiment of H13CON(CH3)2.In this paper,the effect of different cobalt catalysts on photopromoted carbonylation of bromohydrocarbon is studied and the way which photopromoted carbonylation of bromohydrocarbon proceed through is deduced.
Photopromoted carbonylation of alkyl bromides with carbon monoxide or carbon dioxide catalyzed by copper salts can be carried out under ambient conditions (atmospheric pressure and room temperature) and the corresponding ester was produced. The yield and the selectivity of the ester can be improved greatly by addition of sodium phosphate.
Tao WENYing Ping JIADa Bin GAOJing Mei YINIGuang Yun ZHOUJing LIUXiang Sheng WANG
The photo-promoted carbonylation of chloroalkanes with carbon monoxide was carried out under ambient conditions with copper and cadmium salts catalysts. The results indicated that the corresponding esters were produced with three salt catalysts, i.e.CuBr2, CuCl2 and CdI2. Among these catalysts, CdI2 was the most efficient in terms of ester yield and selectivity, particularly, 60% yield and 75% selectivity in the carbonylation of chlorocyclohexane were achieved. Furthermore, the yield and selectivity of the ester can be improved greatly by adding tri-n-butylamine in the CuBr2 and CuCl2 catalyst systems. On the other hand, the additive. As a result, we suggest that iodide ion plays an important role in the catalyst system of the cadmium salts.
Hong Wei Wang Ying Ping Jia Da Bin Gao Jing Mei Yin Guang-Yun-Zhou Shen Min Li
The photopromoted methoxycarbonylation of olefin with methyl formate catalyzed by Co(OAc)2 at ambient conditions has been carried out. The results indicated that the reaction activity increased with the increasing temperature. Methyl formate decomposed into CO and CH3OH firstly under irradiation, and then the methoxycarbonylation of olefin proceeded under catalysis of Co(OAc)2. The mechanism of methyl formate participating in the methoxycarbonylation is verified by the IR analysis and the labeling experiments of CDHOD and CH3^18OH.
Ying Na Cui Jing Mei Yin Da Bin Gao Ying Ping Jia Guang Yun Zhou Shen Min Li
3,4-Hexancdione,An important flavor and synthesis intermediate,was prepared from ethyl propionate by two steps of condensation and oxidation.The conditions were optimized,the yields of two steps reach 75.6% and 69.1% respectively.The products were characterized by IR and 1H NMR.