A new type of heterogeneous catalysis strategy for organic reactions: Ugi-3CR catalyzed by highly stable MOFs with exposed carboxyl groups

Abstract

A mild, highly efficient, and simple Ugi-3CR using a novel organic framework material Cu-COOH@MOF-6 as the catalyst has been developed, which provides facile access to α-amino amides. Cu-COOH@MOF-6 features exposed carboxyl groups in a highly porous metal–organic framework, which explains the relationship between the acid active sites and the catalytic performance of the five-coordinated copper framework. The catalyst used basically maintains its catalytic efficiency after being reused 6 times, and the powder XRD image of the catalyst remained unchanged after the reaction, thus indicating that this catalyst is stable under the reaction conditions.