Propargylic substitution reactions with various nucleophilic compounds using efficient and recyclable mesoporous silica spheres embedded with FeCo/graphitic shell nanocrystals

Seongwan Jang; A Young Kim; Won Seok Seo; Kang Hyun Park

doi:10.1186/1556-276X-10-2

Propargylic substitution reactions with various nucleophilic compounds using efficient and recyclable mesoporous silica spheres embedded with FeCo/graphitic shell nanocrystals

Nanoscale Res Lett. 2015 Jan 23:10:2. doi: 10.1186/1556-276X-10-2. eCollection 2015.

Authors

Seongwan Jang¹, A Young Kim¹, Won Seok Seo², Kang Hyun Park¹

Affiliations

¹ Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, Busan, 609-735 South Korea.
² Department of Chemistry, Sogang University, Seoul, 121-742 South Korea.

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.

Keywords: FeCo/GC; Magnetic; Phosphomolybdic acid; Propargylic substitution; Recyclable.