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Investigation of Alcohols and Thiols Oxidation Via DABCO-Tribromide Catalyst Supported on Silica and Magnetic Iron Oxide Nanoparticles
Saryazdi, Setareh | 2012
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- Type of Document: M.Sc. Thesis
- Language: Farsi
- Document No: 43970 (03)
- University: Sharif University of Technology
- Department: Chemistry
- Advisor(s): Matloubi Moghaddam, Firouz
- Abstract:
- Oxidation reactions in organic chemistry were applied as one of the most important methods to change the functional groups to desired one. Oxidation of alcohols to aldehydes or oxidative coupling of thiols to disulfids is two well-known examples of these conversions. The mention reactions are using commonly because of availability and simple synthesis of the alcohols and thiols. Recently the application of immobilized reagents in solid surfaces is increased because of environmental advantages.
In this study, The 1,4-diazabicyclo[2.2.2] octane (DABCO) tribromide was immobilized on two different supports by employing 3-chloropropyltrimethoxy silane: Silica Support (SS), and Nanoparticles Support (NS). They have been applied in catalytic conversion of thiols to disulfides and alcohols to corresponding aldehydes and ketones. Two methods were employed for recovering the catalysts after the reaction: adding molecular bromine after each cycle (as a common method for recycling of supported tribromide species), and reusing the catalysts directly without adding molecular bromine. A comparison between reactivity and recyclability of these two catalysts was made. Oxidation of alcohols yields in 52-95% and Oxidative coupling reactions of thiols yield in 74-99%. Both catalysts could be recycled three times with two mentioned methods - Keywords:
- Oxidation ; Silicagel ; Thiols ; Magnetic Nanodot ; Magnetic Iron Oxide Nonoparticle
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