A new six-membered cyclic carbonate monomer, 5-allyloxytrimethylene carbonate （ATMC）, was synthesized starting from glycerol, and the corresponding polycarbonates, poly（5-allyloxytrimethylene carbonate）（PATMC） w...A new six-membered cyclic carbonate monomer, 5-allyloxytrimethylene carbonate （ATMC）, was synthesized starting from glycerol, and the corresponding polycarbonates, poly（5-allyloxytrimethylene carbonate）（PATMC） were further synthesized by ring-opening polymerization in bulk at 150℃ using stannous octanoate as an initiator. The structures of the monomer and the polymers were confirmed by IR, IH-NMR, 13C-NMR, and GPC analysis.展开更多
A series of copper-zirconium oxides with the Cu/Zr ratio ranging from 2/8 to 9/1 were synthesized by the co-precipitation method.The PdO/CumZrn catalysts were prepared and applied to synthesis of allyl ethers via the ...A series of copper-zirconium oxides with the Cu/Zr ratio ranging from 2/8 to 9/1 were synthesized by the co-precipitation method.The PdO/CumZrn catalysts were prepared and applied to synthesis of allyl ethers via the etherification reactions of allyl chloride with alcohols.The characterization results demonstrated that the presence of ZrO_(2) phase not only can facilitate the high dispersion of Pd^(2+),but can also favor the formation of Cu^(+) via the interaction between CuO and ZrO_(2).The catalytic performance initially increases and then falls off with the progressive increase in the Cu/Zr ratio.The superior performance with a conversion of 53.2%along with a selectivity of 60.3%was achieved over the resulting PdO/Cu7Zr3 catalyst with the highest surface molar proportion of Cu^(+).Good catalytic activity was obtained,because the Cu^(+)-Oα-pairs could enhance the dissociative activation of the-O-H bond in alcohols compared with Cu^(2+)-O2-pairs,subsequently promoting the etherification reactions.展开更多
A new kind of modified thermoset resins were synthesized by phase-transfer Williamson reaction from novolac resin and mixtures of allyl- and propargyl-chlorides. The compositions of the resins were defined by 1H NMR ...A new kind of modified thermoset resins were synthesized by phase-transfer Williamson reaction from novolac resin and mixtures of allyl- and propargyl-chlorides. The compositions of the resins were defined by 1H NMR （nuclear magnetic resonanse） spectroscopy and the dependence of the cured materials properties on the composition was established. Increase of a propargyl content resulted in char yield raise and the maximum value had been found for propargylated resin--58%. DSC （differential scanning calorimetry）-analysis of the resins has demonstrated that exothermic enthalpy of the curing process could be adjusted by varying the content of propargyl and allyl groups in the resin.展开更多
Chiral homoallylic vicinal diols are found in many bioactive compounds and are among the most versatile functional groups in organic chemistry. Here, we describe an asymmetric carbonyl allylation of aldehydes with all...Chiral homoallylic vicinal diols are found in many bioactive compounds and are among the most versatile functional groups in organic chemistry. Here, we describe an asymmetric carbonyl allylation of aldehydes with allyl ethers proceeding via allylic C-H borylation enabled by palladium and chiral phosphoric acid sequential catalysis, providing facile access to homoallylic vicinal anti-diols in high yields and with excellent stereoselectivity. This protocol enables the total synthesis of aigialomycin D to be finished within 7 steps.展开更多
This paper aims to develop a modified animal glue sand binder for foundry casting with improved water resistance and bonding strength.An efficient method is reported by using sodium hydroxide as the catalyst to improv...This paper aims to develop a modified animal glue sand binder for foundry casting with improved water resistance and bonding strength.An efficient method is reported by using sodium hydroxide as the catalyst to improve the operability of animal glue binder and allyl glycidyl ether as the modifier to improve the water resistance and bonding strength.Sand specimens prepared using allyl glycidyl ether-modified animal glue binder were cured by compressed air at room temperature.The proposed method saves energy and is environmentally friendly and inexpensive.Compared with unmodified animal glue binder,standard dog bone sand specimens with allyl glycidyl ether-modified animal glue binder had higher tensile strength of 2.58 MPa,flowability of 1.95 g,better water resistance(a lower decrease in tensile strength at 25°C and relative humidity of 60%),and good collapsibility.This allyl glycidyl ether-modified animal glue binder is suitable for practical application in the foundry industry.展开更多
We report here a new strategy for revealing the Claisen rearrangement of allyl phenyl ether occurring in the gas phase by in situ GC/MS technique. The Claisen rearrangement has been observed when allyl phenyl ether pa...We report here a new strategy for revealing the Claisen rearrangement of allyl phenyl ether occurring in the gas phase by in situ GC/MS technique. The Claisen rearrangement has been observed when allyl phenyl ether passed through the capillary column at certain temperatures. The relative proportion of rearrangement products is dependent on the temperature of the capillary column and the substituents on the phenyl ring.展开更多
Aromatic-aliphatic polyols were obtained previously from the thiol-ene reactions of propoxylated cardanol with hydroxyalkyl mercaptans;these aromatic-aliphatic polyols were then utilized in the preparation of rigid po...Aromatic-aliphatic polyols were obtained previously from the thiol-ene reactions of propoxylated cardanol with hydroxyalkyl mercaptans;these aromatic-aliphatic polyols were then utilized in the preparation of rigid polyurethane foams with excellent properties.The current work describes a variant of cardanol polyol synthesis by thiol-ene reactions in three steps.The first step is propoxylation of cardanol by reacting cardanol with propylene oxide;the second step is mercaptanization of propoxylated cardanol by reacting double bonds with hydrogen sulfide;and the third step involves the addition of the thiol groups of mercaptanized propoxylated cardanol to the double bonds of allyl alcohol,glycerol-1-allyl ether,and trimethylolpropane allyl ether.Thus,obtained polyols were characterized by standard analytical methods.Rigid polyurethane foams prepared from these polyols show promising physical-mechanical properties.The rigid polyurethane foams can be used for various applications such as thermo-insulation of freezers,storage tanks and pipes for food and chemical industries,wood substitutes and flotation materials.展开更多
基金support of the National Natural Science Foundation of China(Grant No.20104005)
文摘A new six-membered cyclic carbonate monomer, 5-allyloxytrimethylene carbonate （ATMC）, was synthesized starting from glycerol, and the corresponding polycarbonates, poly（5-allyloxytrimethylene carbonate）（PATMC） were further synthesized by ring-opening polymerization in bulk at 150℃ using stannous octanoate as an initiator. The structures of the monomer and the polymers were confirmed by IR, IH-NMR, 13C-NMR, and GPC analysis.
基金The authors are grateful to the financial support from the Jiangsu Province Natural Science Foundation of China(BK20180935)the National Natural Science Foundation of China(22108236)the Yangzhou City Lüyangjinfeng Project of China.
文摘A series of copper-zirconium oxides with the Cu/Zr ratio ranging from 2/8 to 9/1 were synthesized by the co-precipitation method.The PdO/CumZrn catalysts were prepared and applied to synthesis of allyl ethers via the etherification reactions of allyl chloride with alcohols.The characterization results demonstrated that the presence of ZrO_(2) phase not only can facilitate the high dispersion of Pd^(2+),but can also favor the formation of Cu^(+) via the interaction between CuO and ZrO_(2).The catalytic performance initially increases and then falls off with the progressive increase in the Cu/Zr ratio.The superior performance with a conversion of 53.2%along with a selectivity of 60.3%was achieved over the resulting PdO/Cu7Zr3 catalyst with the highest surface molar proportion of Cu^(+).Good catalytic activity was obtained,because the Cu^(+)-Oα-pairs could enhance the dissociative activation of the-O-H bond in alcohols compared with Cu^(2+)-O2-pairs,subsequently promoting the etherification reactions.
基金Sponsored by the National Nature Science Foundation of China (20272018) the Scientific ResearchFoundation for the Returned Overseas Chinese Scholars+1 种基金 State Education Ministry of China and the Nature ScienceFoundation of Guangdong Province (974021 021166)
文摘A new kind of modified thermoset resins were synthesized by phase-transfer Williamson reaction from novolac resin and mixtures of allyl- and propargyl-chlorides. The compositions of the resins were defined by 1H NMR （nuclear magnetic resonanse） spectroscopy and the dependence of the cured materials properties on the composition was established. Increase of a propargyl content resulted in char yield raise and the maximum value had been found for propargylated resin--58%. DSC （differential scanning calorimetry）-analysis of the resins has demonstrated that exothermic enthalpy of the curing process could be adjusted by varying the content of propargyl and allyl groups in the resin.
基金supported by the National Natural Science Foundation of China (21831007)。
文摘Chiral homoallylic vicinal diols are found in many bioactive compounds and are among the most versatile functional groups in organic chemistry. Here, we describe an asymmetric carbonyl allylation of aldehydes with allyl ethers proceeding via allylic C-H borylation enabled by palladium and chiral phosphoric acid sequential catalysis, providing facile access to homoallylic vicinal anti-diols in high yields and with excellent stereoselectivity. This protocol enables the total synthesis of aigialomycin D to be finished within 7 steps.
基金This work was supported by Chongqing Science and Technology Commission(cstc2017shmsA90014)Fundamental Research Funds for the Central Universities(XDJK2019AA003)We thank Kathryn Sole,PhD,from Liwen Bianji,Edanz Group China(www.liwenbianji.cn/ac),for editing the English text of a draft of this manuscript.
文摘This paper aims to develop a modified animal glue sand binder for foundry casting with improved water resistance and bonding strength.An efficient method is reported by using sodium hydroxide as the catalyst to improve the operability of animal glue binder and allyl glycidyl ether as the modifier to improve the water resistance and bonding strength.Sand specimens prepared using allyl glycidyl ether-modified animal glue binder were cured by compressed air at room temperature.The proposed method saves energy and is environmentally friendly and inexpensive.Compared with unmodified animal glue binder,standard dog bone sand specimens with allyl glycidyl ether-modified animal glue binder had higher tensile strength of 2.58 MPa,flowability of 1.95 g,better water resistance(a lower decrease in tensile strength at 25°C and relative humidity of 60%),and good collapsibility.This allyl glycidyl ether-modified animal glue binder is suitable for practical application in the foundry industry.
文摘We report here a new strategy for revealing the Claisen rearrangement of allyl phenyl ether occurring in the gas phase by in situ GC/MS technique. The Claisen rearrangement has been observed when allyl phenyl ether passed through the capillary column at certain temperatures. The relative proportion of rearrangement products is dependent on the temperature of the capillary column and the substituents on the phenyl ring.
文摘Aromatic-aliphatic polyols were obtained previously from the thiol-ene reactions of propoxylated cardanol with hydroxyalkyl mercaptans;these aromatic-aliphatic polyols were then utilized in the preparation of rigid polyurethane foams with excellent properties.The current work describes a variant of cardanol polyol synthesis by thiol-ene reactions in three steps.The first step is propoxylation of cardanol by reacting cardanol with propylene oxide;the second step is mercaptanization of propoxylated cardanol by reacting double bonds with hydrogen sulfide;and the third step involves the addition of the thiol groups of mercaptanized propoxylated cardanol to the double bonds of allyl alcohol,glycerol-1-allyl ether,and trimethylolpropane allyl ether.Thus,obtained polyols were characterized by standard analytical methods.Rigid polyurethane foams prepared from these polyols show promising physical-mechanical properties.The rigid polyurethane foams can be used for various applications such as thermo-insulation of freezers,storage tanks and pipes for food and chemical industries,wood substitutes and flotation materials.
