12 results on '"Otte, Matthias"'
Search Results
2. Nitrogen Atom Transfer Catalysis by Metallonitrene C−H Insertion: Photocatalytic Amidation of Aldehydes.
- Author
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Schmidt‐Räntsch, Till, Verplancke, Hendrik, Lienert, Jonas N., Demeshko, Serhiy, Otte, Matthias, Van Trieste, Gerard P., Reid, Kaleb A., Reibenspies, Joseph H., Powers, David C., Holthausen, Max C., and Schneider, Sven
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AMIDATION ,ALDEHYDES ,CATALYSIS ,ATOMS ,AMINATION ,NITROGEN ,BENZAMIDE ,PHASE-transfer catalysis - Abstract
C−H amination and amidation by catalytic nitrene transfer are well‐established and typically proceed via electrophilic attack of nitrenoid intermediates. In contrast, the insertion of (formal) terminal nitride ligands into C−H bonds is much less developed and catalytic nitrogen atom transfer remains unknown. We here report the synthesis of a formal terminal nitride complex of palladium. Photocrystallographic, magnetic, and computational characterization support the assignment as an authentic metallonitrene (Pd−N) with a diradical nitrogen ligand that is singly bonded to PdII. Despite the subvalent nitrene character, selective C−H insertion with aldehydes follows nucleophilic selectivity. Transamidation of the benzamide product is enabled by reaction with N3SiMe3. Based on these results, a photocatalytic protocol for aldehyde C−H trimethylsilylamidation was developed that exhibits inverted, nucleophilic selectivity as compared to typical nitrene transfer catalysis. This first example of catalytic C−H nitrogen atom transfer offers facile access to primary amides after deprotection. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
3. Highly efficient epoxidation of vegetable oils catalyzed by a manganese complex with hydrogen peroxide and acetic acid
- Author
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Chen, Jianming, De Liedekerke Beaufort, Marc, Gyurik, Lucas, Dorresteijn, Joren, Otte, Matthias, Klein Gebbink, Robertus J.M., Sub Organic Chemistry and Catalysis, Organic Chemistry and Catalysis, Sub Organic Chemistry and Catalysis, and Organic Chemistry and Catalysis
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010405 organic chemistry ,Epoxide ,chemistry.chemical_element ,Homogeneous catalysis ,Manganese ,010402 general chemistry ,01 natural sciences ,Pollution ,0104 chemical sciences ,Catalysis ,chemistry.chemical_compound ,Surface coating ,Acetic acid ,Vegetable oil ,chemistry ,Environmental Chemistry ,Organic chemistry ,Hydrogen peroxide - Abstract
Epoxidized vegetable oils (EVOs) are versatile building blocks for lubricants, plasticizers, polyvinyl chloride (PVC) stabilizers, and surface coating formulations. In this paper, a catalytic protocol for the efficient epoxidation of vegetable oils is presented that is based on a combination of a manganese catalyst, H 2 O 2 as an oxidant, and acetic acid as an additive. This protocol relies on the use of a homogeneous catalyst based on the non-noble metal manganese in combination with a racemic mixture of the N,N′-bis(2-picolyl)-2,2′-bispyrrolidine ligand (rac-BPBP). The optimized reaction conditions entail only 0.03 mol% of the manganese catalyst with respect to the number of double bonds (ca. 0.1 wt% with respect to the oil) and ambient temperature. This epoxidation protocol is highly efficient, since it allows most of the investigated vegetable oils, including cheap waste cooking oil, to be fully epoxidized to EVOs in more than 90% yield with excellent epoxide selectivities (>90%) within 2 h of reaction time. In addition, the protocol takes place in a biphasic reaction medium constituted by the vegetable oil itself and an aqueous acetic acid phase, from which the epoxidized product can be easily separated via simple extraction. In terms of efficiency and reaction conditions, the current epoxidation protocol outperforms previously reported catalytic protocols for plant oil epoxidation, representing a promising alternative method for EVO production.
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- 2019
4. A Cptt‐Based Trioxo‐Rhenium Catalyst for the Deoxydehydration of Diols and Polyols
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Li, Jing, Lutz, Martin, Otte, Matthias, Klein Gebbink, Robertus J. M., Sub Organic Chemistry and Catalysis, Sub Crystal and Structural Chemistry, Organic Chemistry and Catalysis, and Crystal and Structural Chemistry
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ligand design ,chemistry.chemical_element ,Mucic acid ,Homogeneous catalysis ,010402 general chemistry ,01 natural sciences ,Catalysis ,Inorganic Chemistry ,chemistry.chemical_compound ,deoxydehydration ,Glycerol ,Organic chemistry ,Physical and Theoretical Chemistry ,Allyl alcohol ,010405 organic chemistry ,organic chemicals ,Organic Chemistry ,trioxo-rhenium complexes ,Nuclear magnetic resonance spectroscopy ,Rhenium ,homogenous catalysts ,bio-mass conversion ,0104 chemical sciences ,3. Good health ,Solvent ,chemistry - Abstract
Trioxo‐rhenium complexes are well known catalysts for the deoxydehydration (DODH) of vicinal diols (glycols). In this work, we report on the DODH of diols and biomass‐derived polyols using CpttReO3 as a new catalyst (Cptt=1,3‐di‐tert‐butylcyclopentadienyl). The DODH reaction was optimized using 2 mol % of CpttReO3 and 3‐octanol as both reductant and solvent. The CpttReO3 catalyst exhibits an excellent activity for biomass‐derived polyols. Specifically, glycerol is almost quantitatively converted to allyl alcohol and mucic acid gives 75 % of muconates at 91 % conversion. In addition, the loading of CpttReO3 can be reduced to 0.1 mol % to achieve a turn‐over number as high as 900 per Re when using glycerol as substrate. Examination of DODH reaction profiles by NMR spectroscopy indicates that catalysis is related to Cp‐ligand release, which raises questions on the nature of the actual catalyst.
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- 2018
5. Size-Selective Molecular Flasks
- Author
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Otte, Matthias, Sub Organic Chemistry and Catalysis, Organic Chemistry and Catalysis, Sub Organic Chemistry and Catalysis, and Organic Chemistry and Catalysis
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010405 organic chemistry ,Chemistry ,cavities ,Supramolecular chemistry ,Substrate (chemistry) ,General Chemistry ,size-selective catalysis ,010402 general chemistry ,01 natural sciences ,Combinatorial chemistry ,supramolecular chemistry ,Catalysis ,0104 chemical sciences ,Synthetic materials ,organic cages ,Laboratory flask ,Size selectivity ,Organic chemistry ,confined space ,Size selective ,Selectivity - Abstract
Molecular flasks are compounds that are able to mediate or catalyze chemical transformations inside their cavities. The development of such compounds is often inspired by nature. Enzymes, nature’s catalysts, are able to convert a certain substrate with very high turnover number and selectivity. In addition to their very high chemo-, regio-, and stereoselectivity, enzymes are also able to distinguish their substrates on the basis of size, resulting in size selectivity. To date, many synthetic materials such as metal–organic frameworks are used to accomplish size-selective transformations. However, also the number of molecular flasks known to mediate or catalyze size-selective transformations is increasing. In this perspective an overview on classic and the most recent examples of size-selective molecular flasks is given. In addition, an outlook on promising developments in cavity chemistry that may lead to the development of additional size-selective molecular flasks is given.
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- 2016
6. The B(C6F5)3-Catalyzed Tandem Meinwald Rearrangement–Reductive Amination
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Tiddens, Martine R, Klein Gebbink, Robertus J M, Otte, Matthias, Organic Chemistry and Catalysis, and Sub Organic Chemistry and Catalysis
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Tandem ,010405 organic chemistry ,Organic Chemistry ,Imine ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Combinatorial chemistry ,Reductive amination ,0104 chemical sciences ,Catalysis ,chemistry.chemical_compound ,chemistry ,Taverne ,Organic chemistry ,Physical and Theoretical Chemistry ,Amination - Abstract
A system of three coupled catalytic cycles enabling the one-pot transformation of epoxides to amines via Meinwald rearrangement, imine condensation, and imine reduction is described. This assisted tandem catalysis is catalyzed by B(C6F5)3 resulting in the first tandem Meinwald rearrangement-reductive amination protocol. The reaction proceeds in nondried solvents and yields β-functionalized amines. In particular, β-diarylamines are obtained in high yields.
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- 2016
7. Non-Heme Iron Catalysts with a Rigid Bis-Isoindoline Backbone and Their Use in Selective Aliphatic C−H Oxidation
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Chen, Jianming, Lutz, Martin, Milan, Michela, Costas, Miquel, Otte, Matthias, Klein Gebbink, Bert, Organic Chemistry and Catalysis, Crystal and Structural Chemistry, Sub Organic Chemistry and Catalysis, Sub Crystal and Structural Chemistry, Organic Chemistry and Catalysis, Crystal and Structural Chemistry, Sub Organic Chemistry and Catalysis, and Sub Crystal and Structural Chemistry
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Silylation ,product selectivity ,010405 organic chemistry ,Ligand ,CH oxidation ,hydrogen peroxide ,General Chemistry ,Isoindoline ,bioinspired catalysis ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,0104 chemical sciences ,Catalysis ,chemistry.chemical_compound ,iron ,chemistry ,Taverne ,Organic chemistry ,Non heme iron ,Hydrogen peroxide ,Selectivity ,Benzene - Abstract
Iron complexes derived from a bis-isoindoline-bis-pyridine ligand platform based on the BPBP ligand (BPBP = N,N′-bis(2-picolyl)-2,2′-bis-pyrrolidine) have been synthesized and applied in selective aliphatic C–H oxidation with hydrogen peroxide under mild conditions. The introduction of benzene moieties on the bis-pyrrolidine backbone leads to an increased preference of tertiary over secondary C–H bond oxidation (3°/2° ratio up to 33). On the other hand, substituting the meta-position of the pyridines with bulky silyl groups affords enhanced secondary C–H oxidation selectivity and generally leads to higher product yields and mass balances.
- Published
- 2017
8. Mimicry of the 2-His-1-Carboxylate Facial Triad Using Bulky N,N,O-Ligands: Non-Heme Iron Complexes Featuring a Single Facial Ligand and Easily Exchangeable Co-Ligands
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Folkertsma, Emma, De Waard, Esther F., Korpershoek, Gerda, Van Schaik, Arnoldus J., Solozabal Mirón, Naiara, Borrmann, Mandy, Nijsse, Sjoerd, Moelands, Marcel, Lutz, Martin, Otte, Matthias, Moret, Marc-etienne, Klein Gebbink, Robertus J. M., Crystal and Structural Chemistry, Organic Chemistry and Catalysis, Sub Organic Chemistry and Catalysis, Sub Chem Biol & Organic Chem begr 1-6-12, and Sub Crystal and Structural Chemistry
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Steric effects ,Benzimidazole ,N,O ligands ,Stereochemistry ,Metalloenzymes ,Iron ,Epoxidation ,Crystal structure ,010402 general chemistry ,01 natural sciences ,Catalysis ,Inorganic Chemistry ,chemistry.chemical_compound ,O ligands ,Taverne ,medicine ,Moiety ,Carboxylate ,010405 organic chemistry ,Ligand ,Enzyme models ,Triad (anatomy) ,0104 chemical sciences ,medicine.anatomical_structure ,chemistry ,Non-heme iron - Abstract
Mononuclear iron(II) complexes with facially coordinating N,N,O-ligands were synthesized as accurate structural mimics of the 2-His-1-carboxylate facial triad found in mononuclear non-heme iron enzymes. Mimicking of the facial triad is achieved by designing sterically demanding ligands providing two histidine-like benzimidazole moieties and a coordinating carboxylate or ester moiety. The new methyl-substituted analogue of the bis(benzimidazolyl)propionate ligand, BMBMeIP and its ester analogue, BMBMeIPnPr are designed to prevent the formation of previously reported coordinatively saturated FeL2 type complexes. The crystal structure of [Fe(BMBMeIPnPr)(OTf)2] shows a facial N,N,O-coordination that is very similar to the structure of the enzyme active sites. Both [Fe(BMBMeIPnPr)(OTf)2] and [Fe(BMBMeIP)(OTf)(MeCN)n] catalyze the epoxidation of olefins using H2O2, reaching turnover numbers up to 5.8 per iron. These results represent the first examples of iron complexes bearing a single facial and rigid N,N,O-coordinating ligand and three readily available coordination sites showing catalytic activity in oxidation reactions.
- Published
- 2016
9. Encapsulation of Metalloporphyrins in a Self-Assembled Cubic M8L6 Cage: A New Molecular Flask for Cobalt-Porphyrin-Catalysed Radical-Type Reactions.
- Author
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Otte, Matthias, Kuijpers, Petrus F., Troeppner, Oliver, Ivanović‐Burmazović, Ivana, Reek, Joost N. H., and de Bruin, Bas
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MICROENCAPSULATION , *METALLOPORPHYRINS , *NUCLEAR magnetic resonance spectroscopy , *COBALT porphyrins , *TRANSITION metal complexes , *CATALYSIS , *DIAZO compounds - Abstract
The synthesis of a new, cubic M8L6 cage is described. This new assembly was characterised by using NMR spectroscopy, DOSY, TGA, MS, and molecular modelling techniques. Interestingly, the enlarged cavity size of this new supramolecular assembly allows the selective encapsulation of tetra(4-pyridyl)metalloporphyrins (MII(TPyP), M=Zn, Co). The obtained encapsulated cobalt-porphyrin embedded in the cubic zinc-porphyrin assembly is the first example of a catalytically active encapsulated transition-metal complex in a cubic M8L6 cage. The substrate accessibility of this system was demonstrated through radical-trapping experiments, and its catalytic activity was demonstrated in two different radical-type transformations. The reactivity of the encapsulated CoII(TPyP) complex is significantly increased compared to free CoII(TPyP) and other cobalt-porphyrin complexes. The reactions catalysed by this system are the first examples of cobalt-porphyrin-catalysed radical-type transformations involving diazo compounds which occur inside a supramolecular cage. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
10. ChemInform Abstract: Size-Selective Molecular Flasks.
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Otte, Matthias
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ORGANIC chemistry research , *CHEMINFORMATICS , *PHASE-transfer catalysis , *ORGANIC synthesis , *MOLECULARITY - Abstract
Review: 154 refs. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
11. ChemInform Abstract: Encapsulated Cobalt-Porphyrin as a Catalyst for Size-Selective Radical-Type Cyclopropanation Reactions.
- Author
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Otte, Matthias, Kuijpers, Petrus F., Troeppner, Oliver, Ivanovic‐Burmazovic, Ivana, Reek, Joost N. H., and de Bruin, Bas
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SUPRAMOLECULAR chemistry , *ENCAPSULATION (Catalysis) , *COBALT porphyrins , *CYCLOPROPANATION kinetics , *PHASE-transfer catalysis - Abstract
A supramolecular cage catalyst, generated by encapsulation of Co(tetra(4-pyridyl)porphyrin) into a Nitschke-type M8L6 cubic cage is utilized in these reactions. [ABSTRACT FROM AUTHOR]
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- 2014
- Full Text
- View/download PDF
12. ChemInform Abstract: Metalloradical Approach to 2H-Chromenes.
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Paul, Nanda D., Mandal, Sutanuva, Otte, Matthias, Cui, Xin, Zhang, X. Peter, and de Bruin, Bas
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CHEMICAL formulas , *CHEMISTRY - Abstract
Chemical formulas explaining the metalloradical technique to develop 2H-chromenes are presented.
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- 2014
- Full Text
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