Oriented Controllable Fabrication of Metal-Organic Frameworks Membranes as Solid Catalysts for Cascade lndole Acylation-Nazarov Cyclization for Cyclopentenone[b]indoles

摘要

Creating ordered metal-organic frameworks (MOFs) membranes with a scalable fabrication for continuous and homogeneous nanoarchitecture represents a category of tunable and functionalizable heterogeneous catalysts. In this work, we demonstrate a facile synthetic strategy for controlling Cu-MOF (1) to fabricate highly oriented MOF membranes (1a) with good controllability in membranes thickness on the macroporous Ni foam as the supporting scaffold, which can promote the growth of the uniform and high-quality MOF-based membranes with the benefit of readily accessible active sites. Nanoscale crystals of lb also can be acquired by using surfactants as templates without Ni foam as surface-supported. Furthermore, MOFsbased 1-1b have indicated to be efficient heterogeneous catalysts to promote cascade indole acylation-Nazarov cyclization for producing cyclopentenone[b]indoles skeletons. In particular, their unique membrane structure of la, containing ordered structure and molecular tunability, affords a well-defined platform to highly effectively facilitate cyclization reactions by enhancing the diffusional rate and permeability with the minimum diffusion distance but does little for their selectivity.