Axially chiral binaphthol have achieved great success in asymmetric catalysis.Compared toα-binaphthol,axially chiral aryl-β-naphthol are far less reported.Here,we report a method of asymmetric catalysis to construct...Axially chiral binaphthol have achieved great success in asymmetric catalysis.Compared toα-binaphthol,axially chiral aryl-β-naphthol are far less reported.Here,we report a method of asymmetric catalysis to constructβ-naphthol with up to 99%yield,95.5:4.5 enantiomeric ratio,using alkynyl esters as precursors and chiral phosphonic acid(CPA)/Lewis acid as catalysts.Key steps involve oxygen transfer and de novo arene formation to set up the chiral axis.Moreover,this methodology provides a versatile platform for structurally divergent synthesis of atroposelectiveβ-naphthol analogs,which are widely found in bioactive molecules and asymmetric catalysts.展开更多
建立了适用于湖南安化黑茶的高效液相色谱指纹图谱分析方法。样品用水在90℃恒温水浴中浸提20min,以C18色谱柱(250 mm×4.6 mm,5μm)分离,甲醇-0.1%磷酸溶液为流动相梯度洗脱,检测波长为270nm,流速为1.0 m L/min,黑茶的各种组分得...建立了适用于湖南安化黑茶的高效液相色谱指纹图谱分析方法。样品用水在90℃恒温水浴中浸提20min,以C18色谱柱(250 mm×4.6 mm,5μm)分离,甲醇-0.1%磷酸溶液为流动相梯度洗脱,检测波长为270nm,流速为1.0 m L/min,黑茶的各种组分得到较好分离,共确定18个色谱峰作为安化黑茶的特征指纹峰,并通过对照品分析对其中12个峰进行确证。运用相似度评价、主成分分析、正交偏最小方差判别分析(Orthogonal partial least squares discriminant analysis,OPLS-DA)和随机森林法对78个黑茶样品指纹图谱进行了化学模式识别研究和变量重要性判定。结果表明联合指纹图谱分析法和随机森林法可有效区分湖南安化黑茶和其他产地的黑茶。该方法操作简单,精密度、稳定性和重现性良好,为安化黑茶的鉴别和质量控制提供了实验依据。展开更多
基金financial support from the National Natural Science Foundation of China(Nos.22071062,22001077 and 22271096)Guangdong Science and Technology Department(Nos.2021A1515012331,2023A1515011001)+1 种基金the Fundamental Research Funds for the Central Universities(No.2022ZYGXZR016)South China University of Technology for start-up funds。
文摘Axially chiral binaphthol have achieved great success in asymmetric catalysis.Compared toα-binaphthol,axially chiral aryl-β-naphthol are far less reported.Here,we report a method of asymmetric catalysis to constructβ-naphthol with up to 99%yield,95.5:4.5 enantiomeric ratio,using alkynyl esters as precursors and chiral phosphonic acid(CPA)/Lewis acid as catalysts.Key steps involve oxygen transfer and de novo arene formation to set up the chiral axis.Moreover,this methodology provides a versatile platform for structurally divergent synthesis of atroposelectiveβ-naphthol analogs,which are widely found in bioactive molecules and asymmetric catalysts.
文摘建立了适用于湖南安化黑茶的高效液相色谱指纹图谱分析方法。样品用水在90℃恒温水浴中浸提20min,以C18色谱柱(250 mm×4.6 mm,5μm)分离,甲醇-0.1%磷酸溶液为流动相梯度洗脱,检测波长为270nm,流速为1.0 m L/min,黑茶的各种组分得到较好分离,共确定18个色谱峰作为安化黑茶的特征指纹峰,并通过对照品分析对其中12个峰进行确证。运用相似度评价、主成分分析、正交偏最小方差判别分析(Orthogonal partial least squares discriminant analysis,OPLS-DA)和随机森林法对78个黑茶样品指纹图谱进行了化学模式识别研究和变量重要性判定。结果表明联合指纹图谱分析法和随机森林法可有效区分湖南安化黑茶和其他产地的黑茶。该方法操作简单,精密度、稳定性和重现性良好,为安化黑茶的鉴别和质量控制提供了实验依据。
