Engineering of Active Sites in Metal Organic Frameworks for Friedel‐Crafts Alkylation

Abstract

Friedel‐Crafts alkylation reaction is one of the well‐known C‐C bonds forming reactions in organic chemistry catalyzed by homogeneous or heterogeneous catalysts. Aluminosilicates and zeolites have been extensively employed as heterogeneous catalysts between Lewis and Bronsted acids as active sites for this reaction. In this line, metal organic frameworks (MOFs) have also been receiving considerable attention for this reaction in the last two decades. Thus, this review aims to present the catalytic performance of MOFs with Lewis acid/Bronsted acid sites or hydrogen bonding donor sites as potential catalysts to promote the widely employed Friedel‐Crafts alkylation to form C‐C bonds between arenes and electron poor olefins, alcohols, or alkyl bromides. Such acid active sites are present either at the organic linkers or inorganic clusters of the crystalline porous framework, resulting in well‐dispersed heterogeneous active sites able to compete with well‐established homogeneous mineral and organocatalysts. The available literature data grouped based on the nature of active sites. Whenever possible, the comparison of the activity of MOFs with other heterogeneous and homogeneous catalysts is provided to illustrate the possible benefits of MOFs compared to other catalysts. The concluding section provides our views and future developments in this field.