A robust heterogeneous Co-MOF catalyst in azide–alkyne cycloaddition and Friedel–Crafts reactions as well as hydrosilylation of alkynes

Abstract

Organic reactions using metal–organic frameworks (MOFs) as catalysts are promising with regard to their environmentally friendly features and potential catalyst recyclability. A robust Co(II)-MOF {[Co₂(L-mac)(4,4-bpt)(H₂O)]·3.5H₂O}_n (1) and its enantiomer {[Co₂(D-mac)(4,4-bpt)(H₂O)]·3.5H₂O}_n (2) (L/D-mac = basic forms of L/D-malic acid, 4,4-Hbpt = 3,5-di(pyridin-4-yl)-4H-1,2,4-triazole) have been gram-scale prepared under solvothermal conditions. Structural analysis reveals that mac manages Co(II) ions to form 1-D chains, which are further extended via 4,4-bpt connectors into a noninterpenetrating 3D framework architecture. It was found that 1 can be as a heterogeneous catalyst for multiple organic reactions, such as azide-alkyne cycloaddition and Friedel–Crafts reactions with good isolated yields and good recycle runs (at least five times without substantial degradation). Additionally, 1 can promote hydrosilylation of alkynes under harsh conditions with moderate yield.