Polysubstituted cyclopropane was easily constructed from p hydroxyl benzopropene type compounds when catalytic amount PdCl 2 was used. In this paper 1 methyl 2 ethyl 3,3 di(3,5 dimethoxyl 4 hydroxyl)benzocyclopr...Polysubstituted cyclopropane was easily constructed from p hydroxyl benzopropene type compounds when catalytic amount PdCl 2 was used. In this paper 1 methyl 2 ethyl 3,3 di(3,5 dimethoxyl 4 hydroxyl)benzocyclopropane and 1 methyl 2 ethyl 3,3 di(3,5 dihydroxyl 4 methoxyl)benzocyclopropane were first synthesized.展开更多
Carbon supported PdCl_2 is highly active in catalyzing acetylene hydrochlorination reaction, but deactivates rather quickly. Upon nitrogen doping in the carbon structure, the stability of the PdCl_2 catalysts is signi...Carbon supported PdCl_2 is highly active in catalyzing acetylene hydrochlorination reaction, but deactivates rather quickly. Upon nitrogen doping in the carbon structure, the stability of the PdCl_2 catalysts is significantly improved. Furthermore, the results show that 900 ℃ is a preferred doping temperature. The acetylene conversion keeps above 90% even after 1200 min time on stream whereas the one without nitrogen doping drops to below 10% after 450 min. The stabilizing mechanism of nitrogen doping on catalyst was studied.展开更多
The promotion effects of some triflates in the copolymerization of styrene and CO were studied.It was found that PdCl2showed good catalytic activity in the exist of some triflates and among them Cu（OTf）2showed the b...The promotion effects of some triflates in the copolymerization of styrene and CO were studied.It was found that PdCl2showed good catalytic activity in the exist of some triflates and among them Cu（OTf）2showed the best promotion effects.Under the reaction conditions: 1×10-4mol PdCl2,5×10-4mol bipy,2×10-4mol Cu（OTf）2,3×10-3mol BQ,4ml methanol,10ml styrene,T=333K,P=3.0MPa,the catalytic activity of PdCl2/ bipy / M（OTf）nis 18,000gPK/molPd.h.The effects of the amount of Cu（OTf）2and trific acid on PdCl2catalytic activity were also studied.Mechanism of copolymerization catalyzed by this catalytic system wasdiscussed.展开更多
A novel and green method for the synthesis of dimethyl pyridine-3,5-dicarboxylate has been developed. It is PdCl2-catalyzed heterocyclotrimerization of methyl acrylate with urea in methanol/supercritical carbon dioxid...A novel and green method for the synthesis of dimethyl pyridine-3,5-dicarboxylate has been developed. It is PdCl2-catalyzed heterocyclotrimerization of methyl acrylate with urea in methanol/supercritical carbon dioxide. The target compound was obtained with a 75% isolated yield under the optimized con-ditions.展开更多
Reaction of 5'-O-p-methoxytritylthymidine with 1,1'-carbonyl-diimidazole gave the 3'-O-carbonylimidazolide, which was condensed in high yield with 3'-O-protected thymidine to give a dinucleoside carbon...Reaction of 5'-O-p-methoxytritylthymidine with 1,1'-carbonyl-diimidazole gave the 3'-O-carbonylimidazolide, which was condensed in high yield with 3'-O-protected thymidine to give a dinucleoside carbonate. In the synthesis of dinucleoside carbonate, allyl can be used as a good protecting group for 3'-hydroxyl of thymidine. The condition of deprotection will not affect the carbonate bridges.展开更多
基金the National Natural Science Foundation of China(Nos.20773147,21073211 and 21174155)Gansu Provincial Science and Technology Support Project(ID:0708NKCA119)West Light Foundation of the Chinese Academy of Sciences(Y-236)
文摘Polysubstituted cyclopropane was easily constructed from p hydroxyl benzopropene type compounds when catalytic amount PdCl 2 was used. In this paper 1 methyl 2 ethyl 3,3 di(3,5 dimethoxyl 4 hydroxyl)benzocyclopropane and 1 methyl 2 ethyl 3,3 di(3,5 dihydroxyl 4 methoxyl)benzocyclopropane were first synthesized.
基金supported by the National Science Foundation of China(21425312,21373207,21321002)
文摘Carbon supported PdCl_2 is highly active in catalyzing acetylene hydrochlorination reaction, but deactivates rather quickly. Upon nitrogen doping in the carbon structure, the stability of the PdCl_2 catalysts is significantly improved. Furthermore, the results show that 900 ℃ is a preferred doping temperature. The acetylene conversion keeps above 90% even after 1200 min time on stream whereas the one without nitrogen doping drops to below 10% after 450 min. The stabilizing mechanism of nitrogen doping on catalyst was studied.
文摘The promotion effects of some triflates in the copolymerization of styrene and CO were studied.It was found that PdCl2showed good catalytic activity in the exist of some triflates and among them Cu（OTf）2showed the best promotion effects.Under the reaction conditions: 1×10-4mol PdCl2,5×10-4mol bipy,2×10-4mol Cu（OTf）2,3×10-3mol BQ,4ml methanol,10ml styrene,T=333K,P=3.0MPa,the catalytic activity of PdCl2/ bipy / M（OTf）nis 18,000gPK/molPd.h.The effects of the amount of Cu（OTf）2and trific acid on PdCl2catalytic activity were also studied.Mechanism of copolymerization catalyzed by this catalytic system wasdiscussed.
基金the National Natural Science Foundation of China (Grant Nos. 20332030, 20572027, 20625205 and 20772034)Guangdong Natural Science Foundation (Grant No. 07118070)
文摘A novel and green method for the synthesis of dimethyl pyridine-3,5-dicarboxylate has been developed. It is PdCl2-catalyzed heterocyclotrimerization of methyl acrylate with urea in methanol/supercritical carbon dioxide. The target compound was obtained with a 75% isolated yield under the optimized con-ditions.
文摘Reaction of 5'-O-p-methoxytritylthymidine with 1,1'-carbonyl-diimidazole gave the 3'-O-carbonylimidazolide, which was condensed in high yield with 3'-O-protected thymidine to give a dinucleoside carbonate. In the synthesis of dinucleoside carbonate, allyl can be used as a good protecting group for 3'-hydroxyl of thymidine. The condition of deprotection will not affect the carbonate bridges.
