Metal- and covalent organic frameworks as catalyst for organic transformation: Comparative overview and future perspectives

As two newly emerging classes of highly porous compounds, metal–organic frameworks (MOFs) and covalent organic frameworks (COFs), introduced in 1999 and 2005 respectively, have shown promising results for several applications. These materials are now being extensively studied and explored by both academic and industrial scientists as a result of their distinctive properties. Both materials have the advantages of structural tuneability, diversity and high porosity that endow them with tremendous possibilities for multiple applications. The countless combination of building units (metal ions and organic linkers) offers immense structural properties to obtain advanced porous materials. Still, the structural design and advanced applications of these materials are relatively unexplored and deserve further investigation. This review represents the recent development of MOFs and COFs from their syntheses and structural properties to enhanced applications. The unique possibility to introduce a wide range of functionalities to the framework of the materials is comprehensively investigated. We further describe the catalytic sites in MOFs and COFs ranging from metal-free COFs as highly active catalysts to metal-decorated MOFs and COFs. An emphasized application of MOFs/COFs as efficient catalysts is oxidative reactions which is regarded as a crucial transformation in organic synthesis.