Amine-functionalized hyper-crosslinked polyphenanthrene as a metal-free catalyst for the synthesis of 2-amino-tetrahydro-4H-chromene and pyran derivatives

Abstract

The hyper-crosslinked microporous polyphenanthrene spheres were fabricated simply by the polymerization of phenanthrene using bromomethyl methyl ether as a bridging agent in the absence of any templates. The organic spheres were subjected to amine-functionalizing on the periphery of them using unreacted bromomethyl groups. The amine-functionalized microporous polyphenthrene could be employed as a highly effective and stable solid basic catalyst for the syntheses of functionalized 2-amino-tetrahydro-4H-chromene and pyran derivatives. The significant features of these reactions are high product yields, environmental benignity, short reaction time, broad substrate scope, and non-requirement of toxic solvents. Furthermore, the catalyst can be reused up to four times without significant loss of activity.