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

Abstract

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 1b 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 1a, 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.

Reversible Structural Transformations of Metal–Organic Frameworks as Artificial Switchable Catalysts for Dynamic Control of Selectively Cyanation Reaction

“…H 3 CPCDC was synthesized through ap rocedure modi-fied from the literature. [41] 1 HNMR spectroscopy was performed on aB ruker Avance-400 spectrometer.P XRD was executed on a Bruker D8 Advance X-ray diffractometer with Cu Ka 1 radiation. XPS determination was measured on an ESCALAB 250Xi-type instrument.…”

“…[22,33,37,38] In addition, reversible structuralt ransformationso fM OFs could be envisaged as as caffold similar to that of passive transport in enzymes,o f which the arrangemento fs econd and tertiary structuresc ould be acquired to realize trigger-induced effects. [39][40][41] Despite the successful construction of MOF-based catalysts and reversible structural transformations of MOFs, [15-18, 31, 32] MOF-based switchable catalysts that use atomically precise structures are still at an early stage of development. Therefore, new rational synthetic strategies are neededt oa chieve MOF-based artificial switching catalysts in ap redictable fashion.…”

“…Moreover, to mimic the actions of channel enzymes, particular effort has been dedicated to adjusting and controlling reversible structural transformations of heterogeneous catalysts to discern the molecular structure of stimuli‐controlled processes, to provide information on a more distinct catalytic mechanism and richer perspective on the functional performances to illuminate fundamental manmade catalytic chemistry . In addition, reversible structural transformations of MOFs could be envisaged as a scaffold similar to that of passive transport in enzymes, of which the arrangement of second and tertiary structures could be acquired to realize trigger‐induced effects . Despite the successful construction of MOF‐based catalysts and reversible structural transformations of MOFs, MOF‐based switchable catalysts that use atomically precise structures are still at an early stage of development.…”

Synthesis of Heteroarene‐Fused Cyclopentadienes and Related Compounds Suitable for Metallocene Preparation

“…[81,178] 292 and 268 b were obtained in the reaction of Ntosylindole with carboxylic acids in the presence of MOF-based membranes fabricated on porous Ni foam (Scheme 47). [182] The Fischer rearrangement of cyclopentenone arylhydrazones would appear to be a convenient method for the synthesis of indole-fused cyclopentadienes. However, all attempts to implement this approach failed.…”

“…Preparation of N-tosyl-2,3-dihydrocyclopenta[b]indol-1(4H)-ones. [182] Scheme 48. Synthesis of 1,2-dihydrocyclopenta[b]indol-3(4H)ones using the Fischer rearrangement.…”