The Experts below are selected from a list of 1077 Experts worldwide ranked by ideXlab platform
Jidong Lou - One of the best experts on this subject based on the ideXlab platform.
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an efficient and selective oxidation of benzylic and aromatic allylic alcohols with manganese dioxide supported on Kieselguhr under solvent free conditions
Research on Chemical Intermediates, 2013Co-Authors: Liyun Zhu, Zhiyuan Lou, Jianan Lin, Wenjin Zheng, Changhe Zhang, Jidong LouAbstract:An efficient and selective oxidation of benzylic and aromatic allylic alcohols to the corresponding aldehydes and ketones with manganese dioxide supported on Kieselguhr at 50–55 °C under solvent-free conditions in yields between 82 and 96 % is described. All the reactions are completed within 4 h. The merits of the present procedure by comparing with those reporting manganese dioxide oxidation are listed and the possible oxidation mechanism is also described. Aliphatic primary alcohols remain intact by this method.
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an environmentally benign method for oxidation of oximes with potassium permanganate supported on Kieselguhr under solvent free conditions
Research on Chemical Intermediates, 2013Co-Authors: Liyun Zhu, Zhiyuan Lou, Jianan Lin, Wenjin Zheng, Changhe Zhang, Jidong LouAbstract:A rapid and highly efficient procedure for oxidative cleavage of oximes to their parent aldehydes and ketones by grinding with potassium permanganate supported on Kieselguhr at room temperature under solvent-free conditions with yields between 82 and 96 % is described. This method has advantages over previous methods used with potassium permanganate oxidation.
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new reagent manganese dioxide supported on Kieselguhr for effective oxidation of benzoins
Synthetic Communications, 2011Co-Authors: Lihong Huang, Jidong Lou, Qiang Wang, Changhe ZhangAbstract:Abstract A new reagent, manganese dioxide supported on Kieselguhr, for effective oxidation of benzoins into corresponding benzils under heterogeneous and reflux conditions is described. The present oxidations are completed within 10 h with yields of 86–95%. The main advantages of the present procedure are that the preparation of supported reagent is more convenient and the reaction times are relatively short.
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oxidation of benzoins with ferric iii nitrate supported on Kieselguhr
Synthesis and Reactivity in Inorganic Metal-organic and Nano-metal Chemistry, 2008Co-Authors: Guoqiang Wang, Changhe Zhang, Negin Vatanian, Jidong LouAbstract:Efficient and selective oxidation of benzoins to corresponding benzils with ferric(III) nitrate nonahydrate supported on Kieselguhr reagent under heterogeneous conditions and reflux is described. The present oxidations are completed within 2 h with the yield between 85 and 95%. The main advantage of this oxidation is that the reaction time is much shorter as compared to the other reported ferric(III) nitrate nonahydrate–based reagents.
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ferric iii nitrate supported on Kieselguhr a new reagent for selective oxidation of alcohols
Synthetic Communications, 2006Co-Authors: Jidong Lou, Longhua ZhuAbstract:Abstract A selective and effective oxidation of alcohols into the corresponding aldehydes and ketones, respectively, with a new reagent, ferric(III) nitrate supported on Kieselguhr, under heterogeneous conditions is reported.
Zhigang Fang - One of the best experts on this subject based on the ideXlab platform.
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solvent free oxidation of alcohols catalyzed by kmno4 adsorbed on Kieselguhr
Catalysis Communications, 2003Co-Authors: Jidong Lou, Miao Wang, Liyun Zhu, Zhigang FangAbstract:Abstract Efficient and selective oxidation of primary and secondary alcohols to the corresponding aldehydes and ketones catalyzed by potassium permanganate supported on Kieselguhr reagent under solvent free conditions are reported.
Liyun Zhu - One of the best experts on this subject based on the ideXlab platform.
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an efficient and selective oxidation of benzylic and aromatic allylic alcohols with manganese dioxide supported on Kieselguhr under solvent free conditions
Research on Chemical Intermediates, 2013Co-Authors: Liyun Zhu, Zhiyuan Lou, Jianan Lin, Wenjin Zheng, Changhe Zhang, Jidong LouAbstract:An efficient and selective oxidation of benzylic and aromatic allylic alcohols to the corresponding aldehydes and ketones with manganese dioxide supported on Kieselguhr at 50–55 °C under solvent-free conditions in yields between 82 and 96 % is described. All the reactions are completed within 4 h. The merits of the present procedure by comparing with those reporting manganese dioxide oxidation are listed and the possible oxidation mechanism is also described. Aliphatic primary alcohols remain intact by this method.
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an environmentally benign method for oxidation of oximes with potassium permanganate supported on Kieselguhr under solvent free conditions
Research on Chemical Intermediates, 2013Co-Authors: Liyun Zhu, Zhiyuan Lou, Jianan Lin, Wenjin Zheng, Changhe Zhang, Jidong LouAbstract:A rapid and highly efficient procedure for oxidative cleavage of oximes to their parent aldehydes and ketones by grinding with potassium permanganate supported on Kieselguhr at room temperature under solvent-free conditions with yields between 82 and 96 % is described. This method has advantages over previous methods used with potassium permanganate oxidation.
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solvent free oxidation of alcohols catalyzed by kmno4 adsorbed on Kieselguhr
Catalysis Communications, 2003Co-Authors: Jidong Lou, Miao Wang, Liyun Zhu, Zhigang FangAbstract:Abstract Efficient and selective oxidation of primary and secondary alcohols to the corresponding aldehydes and ketones catalyzed by potassium permanganate supported on Kieselguhr reagent under solvent free conditions are reported.
Erich Heftmann - One of the best experts on this subject based on the ideXlab platform.
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Thin-layer chromatography of steroidal sapogenins.
Journal of Chromatography A, 2001Co-Authors: Raymond D. Bennett, Erich HeftmannAbstract:Abstract The application of thin-layer chromatography to the separation of mixtures of steroidal sapogenins and their esters has been investigated. Not only sapogenins differing in the number and kind of polar groups, but also those differing in A/B ring junction and in configuration of hydroxyl and C-25 methyl groups have been resolved. A rapid method for partition chromatography on thin layers of Kieselguhr G was developed. Mixed silica gel-Kieselguhr layers were also found useful, as was a method for acylating hydroxyl groups directly on the thin-layer plate.
Chang Samuel Hsu - One of the best experts on this subject based on the ideXlab platform.
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supercritical carbon dioxide extraction of petroleum on Kieselguhr
Fuel, 2015Co-Authors: Chang Samuel Hsu, Peter J Lee, Jeffrey Wright, Rui Chen, Quan ShiAbstract:Carbon dioxide-based supercritical fluid extraction (CO2 SFE) has been an excellent alternative to solvent extraction in many industries. In this study, a heavy crude oil was adsorbed to Kieselguhr and performed for comparison of different extraction processes. The oil extract by dichloromethane Soxhlet extraction was used as a benchmark. Another batch of the sample was subjected to sequential short-time and longer-time CO2 SFE, and subsequent dichloromethane Soxhlet extraction, yielding three distinct extracts. All of these four extracts were then fractionated by a standard saturates/aromatics/resin/asphaltene (SARA) method. Each SARA fraction was then analyzed by high temperature gas chromatography simulated distillation (SIMDIS), gas chromatography–mass spectrometry (GC–MS) and Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS). It was found that CO2 SFE selectively extracts relatively low molecular weight compounds with low degrees of molecular condensation. The remaining un-extracted components are mainly in polar resin and asphaltene fractions, containing the chemical species with large carbon numbers and high degrees of molecular condensation. Most of these components are in low volatility with boiling points higher than 500 C, beyond the upper temperature limit of common GC columns. CO2 SFE can serve as an environmental-friendly alternative to Soxhlet solvent extraction if the goal of the analysis is to determine petroleum biomarker or compositional analysis by GC–MS. In addition, CO2 SFE for extracts only volatile compounds of small molecular weight has an advantage of leaving most non-volatile components that would be detrimental to the GC systems.
