(R)-N-(β-Trichlorogermyl propionyl)thiazolidine-2-thione-4-carboxylic methyl ether(1) and its sesquioxide(2) were synthesized. The crystal structure of 1 was determined by means of X-ray diffraction analysis, which s...(R)-N-(β-Trichlorogermyl propionyl)thiazolidine-2-thione-4-carboxylic methyl ether(1) and its sesquioxide(2) were synthesized. The crystal structure of 1 was determined by means of X-ray diffraction analysis, which shown that the >CO and >CS groups are located in the opposite sides of C(4)—N—C(3) bond with transconfiguration. The electronic structures and optimized configurations of compounds 1 and 2 were studied with MNDO method.展开更多
A series of esters of R-tetrahydrothiazo-2-thione-4-carboxylic acid [ R-TTCA ] was synthesized by direct esterifica- tion of R-TTCA with alcohols（CH3OH, C2H5OH, n-C3HTOH, i-C3HTOH, n-C4H9OH, sec-C4H9OH） in the prese...A series of esters of R-tetrahydrothiazo-2-thione-4-carboxylic acid [ R-TTCA ] was synthesized by direct esterifica- tion of R-TTCA with alcohols（CH3OH, C2H5OH, n-C3HTOH, i-C3HTOH, n-C4H9OH, sec-C4H9OH） in the presence of TiCl4 as the catalyst at room temperature without using any other solvent or dehydrant in high yields, 91.6%-99.1% for primary alcohols and 55%- 80% for secondary alcohols. The catalyst has a strong chemoselec-tive activity for the esterification of primary alcohols with R-TTCA in the presence of secondary alcohols. Owing to high yield, high chemoselectivity, and mild conditions used, this is an efficient method for the esterification of prima-ry alcohols with R-TTCA.展开更多
（R）-4-Hydroxymethyl-2-thioxo thiazolidine as a new chiral catalyst in the asymmetric addition of diethylzinc to benzaldehyde was synthesized from （R）-4-hydroxymethyl-2-thioxo thiazolidine carboxylic acid and its c...（R）-4-Hydroxymethyl-2-thioxo thiazolidine as a new chiral catalyst in the asymmetric addition of diethylzinc to benzaldehyde was synthesized from （R）-4-hydroxymethyl-2-thioxo thiazolidine carboxylic acid and its crystal structure was determined by X-ray diffraction method. The compound was crystallized in the orthorhombic system, space group P212121 with unit cell dimensions a=0.67253（12） nm; b=0.89164（17） nm; c=1.06146（19） nm, volume 0.6365（2） nm^3; Z=4, calculated denisity 1.557 Mg/m^3; absorption coefficient 0.733 mm^-1; F（000）=312. The X-ray crystal structure analysis reveals that the compound has a thione group.展开更多
Two novel compounds（4a and 4b） were obtained by the association of 2,2,4-trimethyl-3-hydroxy-5-cyclohexenecarboxylate with （S） -isoserine derivatives. The space location of the hydroxyl group of compound 1 was ide...Two novel compounds（4a and 4b） were obtained by the association of 2,2,4-trimethyl-3-hydroxy-5-cyclohexenecarboxylate with （S） -isoserine derivatives. The space location of the hydroxyl group of compound 1 was identified via the formation of lactone 6. Fe2 （SO4）3·xH2O was used as the catalyst for the synthesis of lactone 6. The carboxyl group was selectively protected with diazomethane. All the products were characterized via ^1H NMR and mass spectra. The Docking study showed that the associations have the potential therapeutic use of DPP-Ⅳ inhibitor.展开更多
A series of carboxylic acids was esterified to the corresponding esters with TICl4 as catalyst at room temperature, in high yields. This catalyst was highly effective for the selective esterification of primary alcoho...A series of carboxylic acids was esterified to the corresponding esters with TICl4 as catalyst at room temperature, in high yields. This catalyst was highly effective for the selective esterification of primary alcohols with carboxylic acids, in the presence of secondary alcohols, and for the selective esterification of saturated acid with alcohol in the presence of conjugated acid or aromatic acid. On account of the high yield, high chemoselectivity, mild condition, and being free of other dehydrants, this is an efficient method.展开更多
文摘(R)-N-(β-Trichlorogermyl propionyl)thiazolidine-2-thione-4-carboxylic methyl ether(1) and its sesquioxide(2) were synthesized. The crystal structure of 1 was determined by means of X-ray diffraction analysis, which shown that the >CO and >CS groups are located in the opposite sides of C(4)—N—C(3) bond with transconfiguration. The electronic structures and optimized configurations of compounds 1 and 2 were studied with MNDO method.
文摘A series of esters of R-tetrahydrothiazo-2-thione-4-carboxylic acid [ R-TTCA ] was synthesized by direct esterifica- tion of R-TTCA with alcohols（CH3OH, C2H5OH, n-C3HTOH, i-C3HTOH, n-C4H9OH, sec-C4H9OH） in the presence of TiCl4 as the catalyst at room temperature without using any other solvent or dehydrant in high yields, 91.6%-99.1% for primary alcohols and 55%- 80% for secondary alcohols. The catalyst has a strong chemoselec-tive activity for the esterification of primary alcohols with R-TTCA in the presence of secondary alcohols. Owing to high yield, high chemoselectivity, and mild conditions used, this is an efficient method for the esterification of prima-ry alcohols with R-TTCA.
文摘（R）-4-Hydroxymethyl-2-thioxo thiazolidine as a new chiral catalyst in the asymmetric addition of diethylzinc to benzaldehyde was synthesized from （R）-4-hydroxymethyl-2-thioxo thiazolidine carboxylic acid and its crystal structure was determined by X-ray diffraction method. The compound was crystallized in the orthorhombic system, space group P212121 with unit cell dimensions a=0.67253（12） nm; b=0.89164（17） nm; c=1.06146（19） nm, volume 0.6365（2） nm^3; Z=4, calculated denisity 1.557 Mg/m^3; absorption coefficient 0.733 mm^-1; F（000）=312. The X-ray crystal structure analysis reveals that the compound has a thione group.
基金Supported by the National Natural Science Foundation of China(No. 20172019)
文摘Two novel compounds（4a and 4b） were obtained by the association of 2,2,4-trimethyl-3-hydroxy-5-cyclohexenecarboxylate with （S） -isoserine derivatives. The space location of the hydroxyl group of compound 1 was identified via the formation of lactone 6. Fe2 （SO4）3·xH2O was used as the catalyst for the synthesis of lactone 6. The carboxyl group was selectively protected with diazomethane. All the products were characterized via ^1H NMR and mass spectra. The Docking study showed that the associations have the potential therapeutic use of DPP-Ⅳ inhibitor.
文摘A series of carboxylic acids was esterified to the corresponding esters with TICl4 as catalyst at room temperature, in high yields. This catalyst was highly effective for the selective esterification of primary alcohols with carboxylic acids, in the presence of secondary alcohols, and for the selective esterification of saturated acid with alcohol in the presence of conjugated acid or aromatic acid. On account of the high yield, high chemoselectivity, mild condition, and being free of other dehydrants, this is an efficient method.
