Metal–Organic Layers Hierarchically Integrate Three Synergistic Active Sites for Tandem Catalysis

Abstract

We report the design of abifunctional metal-organic layer (MOL), Hf 12-Ru-Co,c omposed of [Ru(DBB)(bpy) 2 ] 2+ [DBB-Ru, DBB = 4,4'-di(4-benzoato)-2,2'-bipyridine;b py = 2,2'-bipyridine] connecting ligand as ap hotosensitizer and Co(dmgH) 2 (PPA)Cl (PPA-Co,d mgH = dimethylglyoxime; PPA = 4-pyridinepropionic acid) on the Hf 12 secondary building unit (SBU) as ah ydrogen-transfer catalyst. Hf 12-Ru-Co efficiently catalyzedacceptorless dehydrogenation of indolines and tetrahydroquinolines to affordindoles and quinolones.We extended this strategy to prepare Hf 12-Ru-Co-OTf MOL with a[ Ru(DBB)(bpy) 2 ] 2+ photosensitizer and Hf 12 SBU capped with triflate as strong Lewis acids and PPA-Co as ahydrogen transfer catalyst. With three synergistic active sites,Hf 12-Ru-Co-OTfc ompetently catalyzedd ehydrogenative tandem transformations of indolines with alkenes or aldehydes to afford3alkylindoles and bisindolylmethanes with turnover numbers of up to 500 and 460, respectively,illustrating the potential use of MOLs in constructing novel multifunctional heterogeneous catalysts.

Construction and application of base-stable MOFs: a critical review

“…Besides gas capture, storage, and separation, one extensively explored application of MOFs is catalysis. 41,69–72,189–199 As a solid platform, the functional molecular catalysts, like porphyrin and salen, can be easily incorporated into the materials through post-synthetic modification of the frameworks or organic syntheses of the ligands. Moreover, with the development of reticular chemistry, there are more and more reports about inorganic clusters that can only be obtained as secondary building blocks in MOFs.…”

Intermolecular Nucleophilic Addition Reaction of a C-7 Anion from N-[Bis(dimethylamino)phosphoryl]indole to Electrophiles/Arynes: Synthesis of 7-Substituted Indoles

“…NH4Cl solution. After work up and purification, pure 7methyl indole (3a) 11 was obtained as a clear viscous liquid in quantitative yield (99%).…”

“…After interval of 15 minutes, iodomethane (2a; 2.2 equiv), as an electrophile, was added and the mixture was stirred for a further 30 minutes. The reaction was then quenched with aqueous NH 4 Cl and, after workup and purification, 7-methyl-1Hindole (3a) 11 was obtained as a clear viscous liquid in quantitative yield (99%).…”

Compartmentalization and Photoregulating Pathways for Incompatible Tandem Catalysis

“…Scientists have developed multicompartmental catalytic systems based on various strategies including the use of sol–gels, Pickering emulsion droplets, supramolecular metal complex architectures, , and polymers. , Catalytic frameworks fabricated from these materials have realized compartmentalization for multiple active catalytic sites, as epitomized by the cell, and enabled multistep nonorthogonal transformations. − ,− Incorporating responsive elements into the support structures has rendered them “smart”, i.e., allowing for reversible alterations of the physical and chemical properties in response to external stimuli such as temperature, , pH, light, , or enzymes. , The properties of the resulting smart materials impart an additional bioinspired control over single-step catalytic transformations. ,− Manipulation of multicatalytic tandem sequences, however, remains challenging and restricted to the regulation of reactivities via temperature actuation. , This limitation significantly affects the choice of catalysts and limits the feasibility of performing one-pot tandem catalysis at arbitrary temperature ranges. To date, no “smart” catalytic system can use or control different switchable states to tune and activate a desired synthetic pathway among many possible ones during a multistep synthesis.…”