To improve Mixograph testing effect, Farinograph measurements were adopted as a quality standard and changes in water absorption and parameter conversion in Mixograph test were explored. Comparative study showed that ...To improve Mixograph testing effect, Farinograph measurements were adopted as a quality standard and changes in water absorption and parameter conversion in Mixograph test were explored. Comparative study showed that increasing water absorption to about 73% and converting original parameters to compound parameters in Mixograph tests signiifcantly increased their predictive power for lfour quality. These efforts also enabled the adoption of ifxed water addition level in Mixograph test and simpliifed the test procedure signiifcantly. With the success in parameter conversions, Mixograph test results were successful y described by Farinograph parameters, which al ow breeders to compare and exchange test results easily. Al these changes optimized the ofifcial method of Mixograph test with simpliifed procedure and enhanced reliability and made the Mixograph being the superior tool for quality assessment in wheat-breeding programs.展开更多
logP is an importat paramter for evaluating the hydrophobicity of organic compounds and other species. It is widely used in 2D-QSAR and recently in 3D-QSAR studies. On the basis of the current fragment addition method...logP is an importat paramter for evaluating the hydrophobicity of organic compounds and other species. It is widely used in 2D-QSAR and recently in 3D-QSAR studies. On the basis of the current fragment addition method, we proposed a new algo rithm called XLOGP by introducing atomic paramters like atom accessible surfaces, van der Waals volums and partial charges. Step-wise multiple regression on a test set of 400 orgtanic compounds were carried out. The model was then tested by cross-validation. The final correlation coefficient for the whole data set fitting and for cross -validation is 0.982 and 0.971, respectively. This shows that the model obtained is valid both at data fitting and at prediction. Compared to other algorithm, this method can discriminate a common atom or fragment in different environment.展开更多
<正> Solid state Michael addition reaction of indole with α,β-unsaturaled carbonyl compounds was carried out,by which a series of compounds containing three different heterocyclic groups binding to one carbon ...<正> Solid state Michael addition reaction of indole with α,β-unsaturaled carbonyl compounds was carried out,by which a series of compounds containing three different heterocyclic groups binding to one carbon atom were obtained.In the presence of Lewis acid,indole could undergo the solid state condensation reaction with aromatic ketones and aldehydes or quinones.The solid state reaction showed higher selectivity and yield than solution reaction The structures of products were identified by IR,1H NMR,MS,elemental analysis and X-ray crystal analysis.The reaction mechanism was also proposed.展开更多
A facile triphenylphosphine-catalyzed Michael addition of alcohols to acrylic compounds was described. The reaction was carried out in open air at refluxing temperature in the presence of 10 mol% PPh3. Michael additio...A facile triphenylphosphine-catalyzed Michael addition of alcohols to acrylic compounds was described. The reaction was carried out in open air at refluxing temperature in the presence of 10 mol% PPh3. Michael addition of saturated and unsaturated alcohols to acrylonitrile or acrylates has been examined. The reaction gave β-alkoxy derivatives with isolated yields of 5%-79%. PPh3 is cheaper and more stable than those trialkylphosphines previously used for the similar reactions, and the products can be easily separated from the reaction mixture via distillation.展开更多
Polyhydroxy enyne compound （＋）-（1＇S, 2R, 3S, 5S, 6S）-5,6-dimethoxy-5, 6-dimethyl- 2-（1＇-hydroxylpropyl-2-ne）-3-vinyl-l,4-dioxane has been synthesized from D-（-）-tartaric acid. A new chiral center was establ...Polyhydroxy enyne compound （＋）-（1＇S, 2R, 3S, 5S, 6S）-5,6-dimethoxy-5, 6-dimethyl- 2-（1＇-hydroxylpropyl-2-ne）-3-vinyl-l,4-dioxane has been synthesized from D-（-）-tartaric acid. A new chiral center was established by nucleophilic addition with 87% de. The modified Mosher＇s method was employed to confirm the absolute configuration of 17, which assigned the S-configuration at the new chiral center.展开更多
An efficient synthetic procedure for the functionalized spiro[furan-3,3＇-indoline] derivatives was successfully developed by domino reactions of N-phenacylpyridinium bromides or N-ethoxycarbonylmethylenepyridinium br...An efficient synthetic procedure for the functionalized spiro[furan-3,3＇-indoline] derivatives was successfully developed by domino reactions of N-phenacylpyridinium bromides or N-ethoxycarbonylmethylenepyridinium bro- mide with isatinylidene acetoacetate in the presence of triethylamine in ethanol at room temperature. The mecha- nism included sequential Michael addition of the in situ generated pyridinium ylide and intramolecular substitution of enolate.展开更多
基金financially supported by the Knowledge Innovation Program from the Chinese Academy of Sciences (KSCX2-EW-N-02)the State Key Laboratory of Plant Cell and Chromosome Engineering,Ministry of Science and Technology of China
文摘To improve Mixograph testing effect, Farinograph measurements were adopted as a quality standard and changes in water absorption and parameter conversion in Mixograph test were explored. Comparative study showed that increasing water absorption to about 73% and converting original parameters to compound parameters in Mixograph tests signiifcantly increased their predictive power for lfour quality. These efforts also enabled the adoption of ifxed water addition level in Mixograph test and simpliifed the test procedure signiifcantly. With the success in parameter conversions, Mixograph test results were successful y described by Farinograph parameters, which al ow breeders to compare and exchange test results easily. Al these changes optimized the ofifcial method of Mixograph test with simpliifed procedure and enhanced reliability and made the Mixograph being the superior tool for quality assessment in wheat-breeding programs.
文摘logP is an importat paramter for evaluating the hydrophobicity of organic compounds and other species. It is widely used in 2D-QSAR and recently in 3D-QSAR studies. On the basis of the current fragment addition method, we proposed a new algo rithm called XLOGP by introducing atomic paramters like atom accessible surfaces, van der Waals volums and partial charges. Step-wise multiple regression on a test set of 400 orgtanic compounds were carried out. The model was then tested by cross-validation. The final correlation coefficient for the whole data set fitting and for cross -validation is 0.982 and 0.971, respectively. This shows that the model obtained is valid both at data fitting and at prediction. Compared to other algorithm, this method can discriminate a common atom or fragment in different environment.
基金Project supported by the National Natural Science Foundation of China
文摘<正> Solid state Michael addition reaction of indole with α,β-unsaturaled carbonyl compounds was carried out,by which a series of compounds containing three different heterocyclic groups binding to one carbon atom were obtained.In the presence of Lewis acid,indole could undergo the solid state condensation reaction with aromatic ketones and aldehydes or quinones.The solid state reaction showed higher selectivity and yield than solution reaction The structures of products were identified by IR,1H NMR,MS,elemental analysis and X-ray crystal analysis.The reaction mechanism was also proposed.
基金Project supported by the National Natural Science Foundation of China （Nos. 20625205, 20332030 and 20572027）.
文摘A facile triphenylphosphine-catalyzed Michael addition of alcohols to acrylic compounds was described. The reaction was carried out in open air at refluxing temperature in the presence of 10 mol% PPh3. Michael addition of saturated and unsaturated alcohols to acrylonitrile or acrylates has been examined. The reaction gave β-alkoxy derivatives with isolated yields of 5%-79%. PPh3 is cheaper and more stable than those trialkylphosphines previously used for the similar reactions, and the products can be easily separated from the reaction mixture via distillation.
文摘Polyhydroxy enyne compound （＋）-（1＇S, 2R, 3S, 5S, 6S）-5,6-dimethoxy-5, 6-dimethyl- 2-（1＇-hydroxylpropyl-2-ne）-3-vinyl-l,4-dioxane has been synthesized from D-（-）-tartaric acid. A new chiral center was established by nucleophilic addition with 87% de. The modified Mosher＇s method was employed to confirm the absolute configuration of 17, which assigned the S-configuration at the new chiral center.
文摘An efficient synthetic procedure for the functionalized spiro[furan-3,3＇-indoline] derivatives was successfully developed by domino reactions of N-phenacylpyridinium bromides or N-ethoxycarbonylmethylenepyridinium bro- mide with isatinylidene acetoacetate in the presence of triethylamine in ethanol at room temperature. The mecha- nism included sequential Michael addition of the in situ generated pyridinium ylide and intramolecular substitution of enolate.
