title: Propargylic substitution reactions with various nucleophilic compounds using efficient and recyclable mesoporous silica spheres embedded with FeCo/graphitic shell nanocrystals.
abstract: Phosphomolybdic acid (PMA, H3PMo12O40) functioned as a catalyst for reactions of secondary propargylic alcohols and nucleophiles. Highly stable and magnetically recyclable mesoporous silica spheres (MMS) embedded with FeCo-graphitic carbon shell nanocrystals (FeCo/GC@MSS) were fabricated by a modified Stöber process and chemical vapor deposition (CVD) method. The FeCo/GC@MSS were loaded with phosphomolybdic acid (PMA@FeCo/GC@MSS), and their catalytic activity was investigated. Propargylic reactions of 1,3-diphenyl-2-propyn-1-ol with a wide range of nucleophiles bearing activating substituents were catalyzed under mild conditions. It was found that the MMS possess mesoporosities and have enough inner space to load FeCo and phosphomolybdic acid. The FeCo/GC@MSS were found to be chemically stable against acid etching and oxidation. This suggests that the nanocrystals can be used as a support for an acid catalyst. Moreover, the magnetic property of the nanocrystals enabled the facile separation of catalysts from the products.
authors: Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, Busan, 609-735 South Korea.
authors: Seongwan
authors: S
authors: Jang
authors: Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, Busan, 609-735 South Korea.
authors: A Young
authors: AY
authors: Kim
authors: Department of Chemistry, Sogang University, Seoul, 121-742 South Korea.
authors: Won Seok
authors: WS
authors: Seo
authors: Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, Busan, 609-735 South Korea.
authors: Kang Hyun
authors: KH
authors: Park
keywords: FeCo/GC; Magnetic; Phosphomolybdic acid; Propargylic substitution; Recyclable