In an approach to design selectives olid catalysts we start fromt he knowledge,atthe molecularlevel,ofthe reactiontobecatalyzed.Thenhypothesisa re made on then atureo ft he actives itesr equired.A tt hisp oint we are readytosynthesizesolid materials, in where therequiredactivesitesare introduced as well definedentities.On topofthatthe adsorption propertiesof thesolid are taylored to optimizethe interactions between reactants, catalyst andproducts.Following this methodologyw ill presents olid catalysts in where thea ctive sitescorrespondtowelldefinedtransitionmetal complexesand organocatalysts thata re either graftedo rs tructurally builded into solids.In this case, ther oleo ft he solid can go beyond as imple support, since it is designed to interveneinthe reactioneither by stabilizing transitionstatesorbyintroducingadditionalactivesites.Well definedsingleormultiple activesitescan also be introduced into crystallinen anoporous materialsw ith controlleda dsorptionp roperties, andt his allows to perform newacidand redox,one step or multistepreactions.Finallyw ill show that by depositingm etal nanoparticles( Au, Pd,P t) on proactivesupports(CeO 2 ,Fe 2 O 3 , MgO,hydrotalcites,etc.) we can open new catalytic reactionroutesf or C-Cbond formation, oxidations andreductions.These catalytic system allowt he design of multifunctionals olid catalysts, that are able to carryo ut multistepp rocess through cascadet yper eactions that were not possiblebefore.
Eva Meeus opened discussion of the paper by Helma Wennemers: I was wondering whether you could "revert" this process? More specifically, can you equip your peptide-based template to enable length-controlled scissions of oligomers to facilitate, for example, monomer recycling? Helma Wennemers answered: Yes, this i
Abstract Relying on ubiquitous alkenes, carboamination reactions enable the difunctionalization of the double bond by the concurrent formation of a C−N and a C−C single bond. In the past years, several groups have reported on elegant strategies for the carboamination of alkenes relying on homogeneous catalysts or enzymes. Herein, we report on an artificial metalloenzyme for the enantioselective carboamination of dihydrofuran. Genetic optimization, combined with a Bayesian optimization of catalytic performance, afforded the disubstituted tetrahydrofuran product in up to 22 TON and 85 % ee. X‐ray analysis of the evolved artificial carboaminase shed light on critical amino acid residues that affect catalytic performance.
Data underlying the figures in the publication “Synthesis of N-Substituted Indoles via Aqueous Ring-Closing Metathesis?”, published in Catal. Lett.,2021, 151, 1–7. https://doi.org/10.1007/s10562-020-03271-3 Table of contents: 1. Dataset 1; Word file containing the synthetic protocols, catalysis studies and characterization of the compounds.
Thiamine diphosphate (ThDP)-dependent enzymes possess the unique ability to generate a carbene within their active site. In this study, we sought to harness this carbene to produce a Au(I) N-heterocyclic complex directly in the active site of ThDP enzymes, thereby establishing a novel platform for artificial metalloenzymes. Because direct metalation of ThDP proved challenging, we synthesized a ThDP mimic that acts as a competitive inhibitor with a high affinity (Ki = 1.5 μM). Upon metalation with Au(I), we observed that the complex became a more potent inhibitor (Ki = 0.7 μM). However, detailed analysis of the inhibition mode, native mass spectrometry, and size exclusion experiments revealed that the complex does not bind specifically to the active site of ThDP enzymes. Instead, it exhibits unspecific binding and exceeds the 1:1 stoichiometry. Similar binding patterns were observed for other Au(I) species. These findings prompt an important question regarding the inherent propensity of ThDP enzymes to bind strongly to Au. If this phenomenon holds true, it could pave the way for the development of Au-based drugs targeting these enzymes.
Enzymes catalyze a wide variety of chemical reactions with high selectivity and activity under mild conditions. The research strategy in the construction of artificial metalloenzyme relies on noncovalent attachment of the metal moiety using biotin-(strept)avidin technology. The construction of artificial metalloenzyme can be carried out by anchoring a metal moiety within a protein scaffold with the help of an anchoring group. This chapter presents the results obtained upon applying this strategy toward the generation of artificial metalloenzymes for various enantioselective transformations. The palladium-catalyzed asymmetric allylic alkylation (AAA) is a powerful tool for the elaboration of enantiopure high-added value compounds. The current hypothesis is that proteins with a given catalytic function are difficult to use as host for the creation of artificial metalloenzymes. Proteins which merely act as transporters (myoglobin, serum albumins, (strept)avidin, etc.) may be more suited for the creation of artificial metalloenzymes.
