Chemoselective Protection of hydroxyl and amine functional groups catalysed by MOFs

     The Friedel–Crafts reactions are a set of reactions developed to attach substituents to an aromatic ring. There are two main types of Friedel–Crafts reactions: Alkylation and Acylation reactions. The acylation of alcohols, phenols, amines and aromatic compounds with using acetic anhydride, acyl chloride and acetic acid is one of the most important reactions in organic synthesis. Particularly, chemo-selectivity and the curious reactivity preferences of functional groups in chain reactions, like protection of alcohols and amines has received much attention [1]. Recently, different heterogeneous catalysts have been employed to catalyst this reaction [2].

     In this work, we used Metal Organic Frameworks (MOFs) as heterogeneous catalyst for protection reactions of hydroxyl and amine functional groups. MOFs are porous crystalline materials in which metal ions are joined by organic linkers.

     Cu-MOF, Ni-MOF, Co-MOF were separately utilized as efficient and green catalysts for the protection of alcohols and amines with suppliers source of acethyl (Benzyl alcohol/acetic anhydride) to afford protected compounds. Products were obtained in excellent yields within short times under microwave irradiation. The catalyst was recovered without significant decrease in its catalytic activity.