SnCl_2/nano SiO_2: A green and reusable heterogeneous catalyst for the synthesis of polyfunctionalized 4H-pyrans

摘要

A highly effcient and general method for the synthesis of polyfunctionalized 4H-pyrans is established through a one-pot multicomponent cyclocondensation of aromatic aldehydes with CH acids,malononitrile and ethyl acetoacetate using nano silica supported tin(II) chloride as a catalyst. In this method SnCl2/nano SiO2was used as green and reusable catalyst. Excellent yields, short reaction times, simple workup, and inexpensiveness and commercially availability of the catalyst are the advantages of this method.