A hexafluoroisopropanol(HFIP)-catalyzed highly diastereoselective formal[4+2]cyclization between ortho-hydroxyphenyl para-quinone methides and difluoroenoxysilanes is developed.This tandem protocol provides a simple a...A hexafluoroisopropanol(HFIP)-catalyzed highly diastereoselective formal[4+2]cyclization between ortho-hydroxyphenyl para-quinone methides and difluoroenoxysilanes is developed.This tandem protocol provides a simple and straightforward approach to assemble diverse multiply functionalized difluorinated chromans with high to excellent diastereoselectivity by employing difluoroenoxysilane as a new C2 synthon.展开更多
The first HFIP-promoted catalyst-free cascade reactions for the synthesis of biologically relevant 3,3-di(indolyl)indolin-2-ones(27 examples,up to 98% yield) from readily available indoles and isatin derivatives are d...The first HFIP-promoted catalyst-free cascade reactions for the synthesis of biologically relevant 3,3-di(indolyl)indolin-2-ones(27 examples,up to 98% yield) from readily available indoles and isatin derivatives are described.This protocol shows well tolerance of different functional groups and features mild reaction conditions such as short reaction time(~1 h),no usage of catalyst,easy operation and product isolation.Of particular intere st is the formation of two C-C bonds and one all-carbon quaternary center.This protocol could serve as an alternative strategy to synthesize biologically important 3,3-di(indolyl)indolin-2-ones for biological testing.展开更多
Hexafluoroisopropanol(HFIP)-induced sodium dodecyl sulfate/dodecyltrimethylammonium bromide(SDS/DTAB) catanionic surfactant coacervate extraction method coupled with high performance liquid chromatography(HPLC) was us...Hexafluoroisopropanol(HFIP)-induced sodium dodecyl sulfate/dodecyltrimethylammonium bromide(SDS/DTAB) catanionic surfactant coacervate extraction method coupled with high performance liquid chromatography(HPLC) was used to detect the migration of phthalates from disposable tablewares to drinking water. The concentration factors are larger than 82 and extraction recoveries over 53% for water samples spiked with 100 or 200 ng/m L phthalates. Limit of detection is in the range of 1.0–2.6 ng/m L.Good linearity with correlation coefficients larger than 0.9985 is obtained in the concentration of20–1500 or 40–3000 ng/m L. Relative recoveries are from 82.4% to 123.6% for water samples spiked with30/60, 250/500, and 1500/3000 ng/m L phthalates, respectively. Relative standard deviations(RSDs) are0.4%–7.4% for intraday precision(n = 5) and 0.6%–7.8% for interday precision(n = 3). Four of studied phthalates are found in the drinking water samples prepared from four kinds of tablewares.展开更多
基金the financial support from the Natural Science Foundation of Zhejiang Province(No.LQ20B020005)Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(No.2019R01005)Joint Fund of Zhejiang Provincial Natural Science Foundation(No.LTZ21B020001)。
文摘A hexafluoroisopropanol(HFIP)-catalyzed highly diastereoselective formal[4+2]cyclization between ortho-hydroxyphenyl para-quinone methides and difluoroenoxysilanes is developed.This tandem protocol provides a simple and straightforward approach to assemble diverse multiply functionalized difluorinated chromans with high to excellent diastereoselectivity by employing difluoroenoxysilane as a new C2 synthon.
基金supported by the National Natural Science Foundation of China(Nos.81773562,81703326 and 81973177)The Open Project of State Key Laboratory of Natural Medicines(No.SKLNMKF202005)China Postdoctoral Science Foundation(Nos.2018M630840 and 2019T120641)。
文摘The first HFIP-promoted catalyst-free cascade reactions for the synthesis of biologically relevant 3,3-di(indolyl)indolin-2-ones(27 examples,up to 98% yield) from readily available indoles and isatin derivatives are described.This protocol shows well tolerance of different functional groups and features mild reaction conditions such as short reaction time(~1 h),no usage of catalyst,easy operation and product isolation.Of particular intere st is the formation of two C-C bonds and one all-carbon quaternary center.This protocol could serve as an alternative strategy to synthesize biologically important 3,3-di(indolyl)indolin-2-ones for biological testing.
基金the National Natural Science Foundation of China(Grant no.81373045)the Provincial Natural Science Foundation of Hubei of China(Grant no.2015CFA139)
文摘Hexafluoroisopropanol(HFIP)-induced sodium dodecyl sulfate/dodecyltrimethylammonium bromide(SDS/DTAB) catanionic surfactant coacervate extraction method coupled with high performance liquid chromatography(HPLC) was used to detect the migration of phthalates from disposable tablewares to drinking water. The concentration factors are larger than 82 and extraction recoveries over 53% for water samples spiked with 100 or 200 ng/m L phthalates. Limit of detection is in the range of 1.0–2.6 ng/m L.Good linearity with correlation coefficients larger than 0.9985 is obtained in the concentration of20–1500 or 40–3000 ng/m L. Relative recoveries are from 82.4% to 123.6% for water samples spiked with30/60, 250/500, and 1500/3000 ng/m L phthalates, respectively. Relative standard deviations(RSDs) are0.4%–7.4% for intraday precision(n = 5) and 0.6%–7.8% for interday precision(n = 3). Four of studied phthalates are found in the drinking water samples prepared from four kinds of tablewares.
