Nanomagnetic double-charged diazoniabicyclo[2.2.2]octane dichloride silica as a novel nanomagnetic phase-transfer catalyst for the aqueous synthesis of benzyl acetates and thiocyanates

摘要

Nanomagnetic double-charged diazoniabicydo[2.2.2]octane dichloride silica hybrid (Fe3O4@SiO2/DABCO) was used as an efficient and magnetically recoverable phase-transfer catalyst (PTC) for nucleophilic substitution reactions of benzyl halides for the synthesis of benzyl acetates and thiocyanates in good to excellent yields at 100 °C in water. No evidence for the formation of by-products, for example, isothiocyanate or benzyl alcohol was observed and the products were obtained in pure form without further purification. The catalyst was easily separated with the assistance of an external magnetic field from the reaction mixture and reused for several consecutive runs without significant loss of its catalytic efficiency.