The esterification of carboxylic acid with alcohol in the presence of catalytic amounts of mineral acids is one of the most methods for preparing esters.The catalysts generally preferred are sulfuric acid or p-toluene...The esterification of carboxylic acid with alcohol in the presence of catalytic amounts of mineral acids is one of the most methods for preparing esters.The catalysts generally preferred are sulfuric acid or p-toluenesulfonic acid.But the products esters were racemic when（S）-3-（2′-oxocyclohexyl） propionic acid reacts with alcohols in the presence of sulfuric acid or with p-toluenesulfonic acid as catalyst.We replace sulfuric acid with Fe2(SO4)3·xH2O as the catalyst.The optical compound（S）-methyl-3-（2′-oxocyclohexyl）propionate,（（S）-ethyl-3-）（2′-oxocyclohexyl）propionate and（S）-n-butyl-3-（2′-oxocyclohexyl）propionate were obtained.In this paper we also reported that cyclohexanone reacted with methyl acrylate in the presence of potassium thiazolidine-2-thione-4-carboxylate（R）TTCA·K as the chiral catalyst to afford optically active（S）-3-（2′-oxocy-clohexyl） propionate.The mechanism of reaction of cyclohexanone with methyl acrylate in the presence of（R）TTCA·K as the catalyst would be a complex process.展开更多
Tetranuclear Cu(I)complex,Cu4(imdt)(NO3)4.6H2O(imdt=1,3-imidazolidine-2-thione),was synthesized by areaction of Cu(NO3)2with imdt in water.It crystallizes in monoclinic crystal system,space group C2/c(No.15),with a =3...Tetranuclear Cu(I)complex,Cu4(imdt)(NO3)4.6H2O(imdt=1,3-imidazolidine-2-thione),was synthesized by areaction of Cu(NO3)2with imdt in water.It crystallizes in monoclinic crystal system,space group C2/c(No.15),with a =3.1418(3)nm,b =0.94332(6) nm,c =2.3027(2) nm,β=119.773(3)°,V =5.9236(9) nm3,Z =4,Mr=1529.68.mol-1,Dc.=1.715g.cm-3,μ=1.815 mm-1,F(000) =3144,R1=0.028,wR2=0.065.The crystal structure consists of tetranuclear[Cu4(imdt)9]4 +cation,in which Cu(I)is coordinated with four S atoms from four imdt ligands to form a distorted tetrahedral geometryand imdt ligands exhibit three coordination modes of terminal monodentate S-donating andμ2—S andμ4—S bridging coordina-tion.展开更多
文摘The esterification of carboxylic acid with alcohol in the presence of catalytic amounts of mineral acids is one of the most methods for preparing esters.The catalysts generally preferred are sulfuric acid or p-toluenesulfonic acid.But the products esters were racemic when（S）-3-（2′-oxocyclohexyl） propionic acid reacts with alcohols in the presence of sulfuric acid or with p-toluenesulfonic acid as catalyst.We replace sulfuric acid with Fe2(SO4)3·xH2O as the catalyst.The optical compound（S）-methyl-3-（2′-oxocyclohexyl）propionate,（（S）-ethyl-3-）（2′-oxocyclohexyl）propionate and（S）-n-butyl-3-（2′-oxocyclohexyl）propionate were obtained.In this paper we also reported that cyclohexanone reacted with methyl acrylate in the presence of potassium thiazolidine-2-thione-4-carboxylate（R）TTCA·K as the chiral catalyst to afford optically active（S）-3-（2′-oxocy-clohexyl） propionate.The mechanism of reaction of cyclohexanone with methyl acrylate in the presence of（R）TTCA·K as the catalyst would be a complex process.
文摘Tetranuclear Cu(I)complex,Cu4(imdt)(NO3)4.6H2O(imdt=1,3-imidazolidine-2-thione),was synthesized by areaction of Cu(NO3)2with imdt in water.It crystallizes in monoclinic crystal system,space group C2/c(No.15),with a =3.1418(3)nm,b =0.94332(6) nm,c =2.3027(2) nm,β=119.773(3)°,V =5.9236(9) nm3,Z =4,Mr=1529.68.mol-1,Dc.=1.715g.cm-3,μ=1.815 mm-1,F(000) =3144,R1=0.028,wR2=0.065.The crystal structure consists of tetranuclear[Cu4(imdt)9]4 +cation,in which Cu(I)is coordinated with four S atoms from four imdt ligands to form a distorted tetrahedral geometryand imdt ligands exhibit three coordination modes of terminal monodentate S-donating andμ2—S andμ4—S bridging coordina-tion.
