A new nucleophilic 1,3-rearrangement is observed when treating 2-methoxyquinolino-3-lithium with an α-C substituted deoxybenzoin,and this rearrangement yielded an unusual 3,4-disubstituted 3,4-dihydroquinoline.Severa...A new nucleophilic 1,3-rearrangement is observed when treating 2-methoxyquinolino-3-lithium with an α-C substituted deoxybenzoin,and this rearrangement yielded an unusual 3,4-disubstituted 3,4-dihydroquinoline.Several similar reactions were designed and executed to investigate this novel 1,3-rearrangement,and a mechanism involving a nucleophilic addition and a following 1,3-rearrangement with an unusual dearomatization on the quinoline ring is proposed.展开更多
An electrocatalytic 3,3-rearrangement/cyclization approach has been developed for the transformation of arylsubstituted propargylic aryl ethers to naphtho[1,2-b]furan-2-carbaldehyde and naphtho[2,1-b]furan-2-carbaldeh...An electrocatalytic 3,3-rearrangement/cyclization approach has been developed for the transformation of arylsubstituted propargylic aryl ethers to naphtho[1,2-b]furan-2-carbaldehyde and naphtho[2,1-b]furan-2-carbaldehyde derivatives.The reaction proceeded efficiently under mild conditions in the absence of metal-and chemicaloxidant,yielding the desired products with good substrate scope and functional group tolerance via a radical pathway.Furthermore,the control experiment revealed that the phenylselenyl-substituted secondary alcohol might be intermediate,and the ^(18)O labeling reaction indicated the oxygen source in the product possibly deriving from water.Significantly,further transformations of the product were conducted to showcase the utility of this electrosynthesis strategy.展开更多
目的建立气相色谱-串联质谱法(gas chromatography-tandem mass spectrometry,GC-MS/MS)快速测定婴幼儿配方奶粉、冷冻饮品及食用油中2-氯-1,3-丙二醇(2-monochloropropane-1,3-diol,2-MCPD)和3-氯-1,2-丙二醇(3-monochloropropane-1,2-...目的建立气相色谱-串联质谱法(gas chromatography-tandem mass spectrometry,GC-MS/MS)快速测定婴幼儿配方奶粉、冷冻饮品及食用油中2-氯-1,3-丙二醇(2-monochloropropane-1,3-diol,2-MCPD)和3-氯-1,2-丙二醇(3-monochloropropane-1,2-diol,3-MCPD)的分析方法。方法本研究基于苯基硼酸作为衍生试剂,样品经氯化钠水溶液提取,玻璃硅藻土小柱净化,高速冷冻离心,加入一定量水去除过量苯基硼酸进行测定。以5%苯基-甲基聚硅氧烷毛细管色谱柱(30 m×0.25 mm,0.25μm)进行分离,质谱采用电子轰击源(electron bombardment ion source,EI)电离,选择反应监测(selected reaction monitoring,SRM)模式对婴幼儿配方奶粉、冷冻饮品及食用油中2-MCPD和3-MCPD进行定性和定量分析。结果该方法在婴幼儿配方奶粉、冷冻饮品及食用油3种基质中,方法线性范围为10~400 ng/mL,相关系数均在0.99以上,平均回收率在84.0%~107.8%之间,相对标准偏差(relative standard deviations,RSDs)在1.1%~9.3%之间。婴幼儿配方奶粉和冷冻饮品中2-MCPD和3-MCPD检出限均为10μg/kg;食用油中2-MCPD和3-MCPD检出限为30μg/kg;婴幼儿配方奶粉和冷冻饮品中2-MCPD和3-MCPD定量限均为25μg/kg;食用油中2-MCPD和3-MCPD定量限为100μg/kg。结论本方法样品前处理快速、简单,净化效果好,结果准确性高,适用于婴幼儿配方奶粉、冷冻饮品及食用油中2-MCPD和3-MCPD快速检测分析。展开更多
基金‘‘The National High-Tech Research and Development Program (‘‘863’’Program) of China’’No. 2012AA020302) for financial support
文摘A new nucleophilic 1,3-rearrangement is observed when treating 2-methoxyquinolino-3-lithium with an α-C substituted deoxybenzoin,and this rearrangement yielded an unusual 3,4-disubstituted 3,4-dihydroquinoline.Several similar reactions were designed and executed to investigate this novel 1,3-rearrangement,and a mechanism involving a nucleophilic addition and a following 1,3-rearrangement with an unusual dearomatization on the quinoline ring is proposed.
基金National Natural Science Foundation of China(Nos.22301128 and 22301272)the Natural Science Foundation of Hunan Province(No.2022JJ40353)for financial support.
文摘An electrocatalytic 3,3-rearrangement/cyclization approach has been developed for the transformation of arylsubstituted propargylic aryl ethers to naphtho[1,2-b]furan-2-carbaldehyde and naphtho[2,1-b]furan-2-carbaldehyde derivatives.The reaction proceeded efficiently under mild conditions in the absence of metal-and chemicaloxidant,yielding the desired products with good substrate scope and functional group tolerance via a radical pathway.Furthermore,the control experiment revealed that the phenylselenyl-substituted secondary alcohol might be intermediate,and the ^(18)O labeling reaction indicated the oxygen source in the product possibly deriving from water.Significantly,further transformations of the product were conducted to showcase the utility of this electrosynthesis strategy.
文摘目的建立气相色谱-串联质谱法(gas chromatography-tandem mass spectrometry,GC-MS/MS)快速测定婴幼儿配方奶粉、冷冻饮品及食用油中2-氯-1,3-丙二醇(2-monochloropropane-1,3-diol,2-MCPD)和3-氯-1,2-丙二醇(3-monochloropropane-1,2-diol,3-MCPD)的分析方法。方法本研究基于苯基硼酸作为衍生试剂,样品经氯化钠水溶液提取,玻璃硅藻土小柱净化,高速冷冻离心,加入一定量水去除过量苯基硼酸进行测定。以5%苯基-甲基聚硅氧烷毛细管色谱柱(30 m×0.25 mm,0.25μm)进行分离,质谱采用电子轰击源(electron bombardment ion source,EI)电离,选择反应监测(selected reaction monitoring,SRM)模式对婴幼儿配方奶粉、冷冻饮品及食用油中2-MCPD和3-MCPD进行定性和定量分析。结果该方法在婴幼儿配方奶粉、冷冻饮品及食用油3种基质中,方法线性范围为10~400 ng/mL,相关系数均在0.99以上,平均回收率在84.0%~107.8%之间,相对标准偏差(relative standard deviations,RSDs)在1.1%~9.3%之间。婴幼儿配方奶粉和冷冻饮品中2-MCPD和3-MCPD检出限均为10μg/kg;食用油中2-MCPD和3-MCPD检出限为30μg/kg;婴幼儿配方奶粉和冷冻饮品中2-MCPD和3-MCPD定量限均为25μg/kg;食用油中2-MCPD和3-MCPD定量限为100μg/kg。结论本方法样品前处理快速、简单,净化效果好,结果准确性高,适用于婴幼儿配方奶粉、冷冻饮品及食用油中2-MCPD和3-MCPD快速检测分析。
