University of Tehran Journal of Sciences, Islamic Republic of Iran 1016-1104 26 3 2015 09 01 Poly (vinylpyrrolidone)-Grafted Silica as a Polymeric Cosolvent Catalyst for Organic Transformations in Organic and Aqueous Media 223 231 55310 EN S. Ghasemi Department of Chemistry, Faculty of Sciences, Shiraz University, Shiraz 7194684795, Islamic Republic of Iran B. Tamami Department of Chemistry, Faculty of Sciences, Shiraz University, Shiraz 7194684795, Islamic Republic of Iran R. Teymoori Department of Chemistry, Faculty of Sciences, Shiraz University, Shiraz 7194684795, Islamic Republic of Iran H. Allahyari Department of Chemistry, Faculty of Sciences, Shiraz University, Shiraz 7194684795, Islamic Republic of Iran Journal Article 2015 04 20 <span>Poly (vinylpyrrolidone)-grafted silica as an organic-inorganic hybrid material was used as an effective heterogeneous polymeric cosolvent catalyst in organic reactions. This modified silica catalyzed nucleophilic displacement of alkyl halides for easy preparation of alkyl thiocyanates, alkyl cyanides, alkyl azides and alkyl aryl ethers. Furthermore, the catalyst was applied for the conversion of epoxides to thiranes, thiocyanohydrins and azidohydrins. These reactions were performed in acetonitrile and aqueous media to produce the corresponding products in high yields and short reaction times. The catalyst can be recovered and reused several times.</span> https://jsciences.ut.ac.ir/article_55310_115583b73a7ed3b54b99894b05ecf63e.pdf