The enantioselective double Michael reaction of benzofuranone with dienones catalyzed by Cinchona-based primary amines was developed. A number of optically active spirocyclic benzofuranones were obtained in up to 89% ...The enantioselective double Michael reaction of benzofuranone with dienones catalyzed by Cinchona-based primary amines was developed. A number of optically active spirocyclic benzofuranones were obtained in up to 89% yield and 91% ee.展开更多
采用高效液相色谱仪建立了测定苯并呋喃酮的定量定性分析方法。采用C18不锈钢柱(150 mm×4.6 mm i.d.,5μm)和二极管阵列检测器,乙腈、甲醇和0.1%磷酸水溶液为流动相,梯度洗脱,在268 nm波长下对苯并呋喃酮进行分离和定量分析。结果...采用高效液相色谱仪建立了测定苯并呋喃酮的定量定性分析方法。采用C18不锈钢柱(150 mm×4.6 mm i.d.,5μm)和二极管阵列检测器,乙腈、甲醇和0.1%磷酸水溶液为流动相,梯度洗脱,在268 nm波长下对苯并呋喃酮进行分离和定量分析。结果表明,该方法测得苯并呋喃酮的保留时间为10.1 min,线性相关系数为0.9999,标准偏差为0.09,变异系数为0.13%,平均回收率为100.02%。该方法具有操作简便、快速稳定、结果准确等特点,可满足苯并呋喃酮生产过程中的定量分析和质量控制要求。展开更多
A quinine-derived thiourea-catalyzed inter-/intramolecular Michael cycloaddition of chromoneoxindole/benzofuranone synthons with 3-substituted methylenebenzofuranones has been established,which constructed enantiomeri...A quinine-derived thiourea-catalyzed inter-/intramolecular Michael cycloaddition of chromoneoxindole/benzofuranone synthons with 3-substituted methylenebenzofuranones has been established,which constructed enantiomerically pure bispiro[benzofuran-oxindole/benzofuran-chromanone]s bearing five consecutive stereocenters including two spiro quaternary carton centers in good yields(up to 93%) with high diastereoselectivities(up to>20:1 dr) and good enantioselectivities(up to>99% ee).Moreover,this is the first example of bifunctional chromone-benzofuranone synthon directed organocatalytic tandem reaction,and also the first example of the bispiro[benzofuran-oxindole] and bispirobenzofuranone,potentially useful in medicinal chemistry.展开更多
The rate constants for the hydrogen donation of three 3-aryl-benzofuranone compounds with tert-butoxyl radicals have been cal-culated through laser flash photolysis (LFP) technique, which were used to evaluate the hyd...The rate constants for the hydrogen donation of three 3-aryl-benzofuranone compounds with tert-butoxyl radicals have been cal-culated through laser flash photolysis (LFP) technique, which were used to evaluate the hydrogen donating abilities of those 3-aryl-benzofuranone compounds. The antioxidant activities of those 3-aryl-benzofuranone compounds in polypropylene (PP) have been studied using the oxidation induction time (OIT) of PP stabilized by those 3-aryl-benzofuranone compounds too. It has been found that the methyl group on the 2'-position can prevent the hydrogen donation of 3-aryl-benzofuranone with tert-butoxyl radicals and weakens the antioxidant activity of 3-aryl-benzofuranone in the oxidation of PP, i.e., the greater is the hydrogen do-nating ability of 3-aryl-benzofuranone with radicals, the better is the antioxidant activity of 3-aryl-benzofuranone in the oxidation of PP in the presence of oxygen.展开更多
基金Acknowledgement This work was supported by National Natural Science Foundation of China （Nos. 20802075 and No. 21042006）.
文摘The enantioselective double Michael reaction of benzofuranone with dienones catalyzed by Cinchona-based primary amines was developed. A number of optically active spirocyclic benzofuranones were obtained in up to 89% yield and 91% ee.
基金financial support from the National Nature Science Foundation of China(Nos.81760625,81660576 and81560563)Projects of Guizhou Province(Nos.[2016]5623,JG[2016]06,[2019]1402,[2017]5609 and[2018]5781)。
文摘A quinine-derived thiourea-catalyzed inter-/intramolecular Michael cycloaddition of chromoneoxindole/benzofuranone synthons with 3-substituted methylenebenzofuranones has been established,which constructed enantiomerically pure bispiro[benzofuran-oxindole/benzofuran-chromanone]s bearing five consecutive stereocenters including two spiro quaternary carton centers in good yields(up to 93%) with high diastereoselectivities(up to>20:1 dr) and good enantioselectivities(up to>99% ee).Moreover,this is the first example of bifunctional chromone-benzofuranone synthon directed organocatalytic tandem reaction,and also the first example of the bispiro[benzofuran-oxindole] and bispirobenzofuranone,potentially useful in medicinal chemistry.
基金supported by the National Natural Science Foundation of China (Grant No 20806023)East China University of Science and Technology (Grant No YA0157107)
文摘The rate constants for the hydrogen donation of three 3-aryl-benzofuranone compounds with tert-butoxyl radicals have been cal-culated through laser flash photolysis (LFP) technique, which were used to evaluate the hydrogen donating abilities of those 3-aryl-benzofuranone compounds. The antioxidant activities of those 3-aryl-benzofuranone compounds in polypropylene (PP) have been studied using the oxidation induction time (OIT) of PP stabilized by those 3-aryl-benzofuranone compounds too. It has been found that the methyl group on the 2'-position can prevent the hydrogen donation of 3-aryl-benzofuranone with tert-butoxyl radicals and weakens the antioxidant activity of 3-aryl-benzofuranone in the oxidation of PP, i.e., the greater is the hydrogen do-nating ability of 3-aryl-benzofuranone with radicals, the better is the antioxidant activity of 3-aryl-benzofuranone in the oxidation of PP in the presence of oxygen.
