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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. Less is more! Diols and biomass‐derived polyols, sustainable starting materials, were efficiency converted to very useful industrial olefin building blocks by using CpttReO3 as catalyst and a secondary alcohol as reductant. Remarkably, 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. [ABSTRACT FROM AUTHOR]

A three-dimensional (3-D) elastic registration algorithm has been developed to find a veridical transformation that maps activation patterns from functional magnetic resonance imaging (fMRI) experiments onto a 3-D high-resolution anatomical dataset. The proposed algorithm uses trilinear Bezier-splines and a 3-D voxel-based optimization technique to determine the transformation that maps the functional data onto the coordinate system of the anatomical dataset. Simple conditions are presented which guarantee that the data are mapped one-to-one on each other. Two voxel-based similarity measures, the linear correlation coefficient and the entropy correlation coefficient, are used. Their performance with respect to the registration of fMRI data is compared. Tests on simulated and real data have been performed to evaluate the accuracy of the method. Our results demonstrate that subvoxel accuracy can be achieved even for noisy low-resolution multislice datasets with local distortions up to 10 mm. Although the method is optimized for the registration of functional and anatomical MR images, it can also be used for solving other elastic registration problems. Index Terms--Bezier splines, elastic registration, fMRI, one-to-one transformations.

Keywords: bioinorganic chemistry; confined space; organocatalysis; self-assembly; size-selective catalysis EN bioinorganic chemistry confined space organocatalysis self-assembly size-selective catalysis 1 1 1 05/11/23 20230508 NES 230508 B The Front Cover b illustrates the self-assembly of a cartoon parachute group conducting experiments. Bioinorganic chemistry, confined space, organocatalysis, self-assembly, size-selective catalysis Front Cover: Reactions in Endohedral Functionalized Cages (Eur. J. Org. [Extracted from the article]

A method for the regioselective transformation of dienes to carbonyl compounds has been developed. Electron-rich olefins react selectively to yield valuable aldehydes and ketones. The method is based on the catalyst [Fe(OTf)2(mix-BPBP)] with an oxidant combination of H2O2 (1.0 equiv.) and NaIO4 (1.5 equiv.); it uses mild conditions and short reaction times, and it outperforms other olefin cleavage methodologies. [ABSTRACT FROM AUTHOR]

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]

A system for coupling catalytic radical cyclization and Ir-catalyzed hydrogen atom transfer (HAT) is described. It is essential that the HAT catalyst activates H2 quickly and is not a hydrogenation catalyst. Vaska's complex was found to fulfill both purposes efficiently. [ABSTRACT FROM AUTHOR]

A method for the regioselective transformation of dienes to carbonyl compounds has been developed. Electron-rich olefins react selectively to yield valuable aldehydes and ketones. The method is based on the catalyst [Fe(OTf)2(mix-BPBP)] with an oxidant combination of H2O2 (1.0 equiv.) and NaIO4 (1.5 equiv.); it uses mild conditions and short reaction times, and it outperforms other olefin cleavage methodologies. [ABSTRACT FROM AUTHOR]

Various aldehydes and ketones are selectively obtained by cleavage of internal double bonds under mild reaction conditions without significant over-oxidation. [ABSTRACT FROM AUTHOR]

The active site of particulate methane monooxygenase (pMMO) and its mechanism of action are not known. Recently, the Cu C site emerged as a potential active site, but to date it lacks any study on biomimetic resemblance of the coordination environment provided by the enzyme. Here, the synthesis of a cage ligand providing such an environment is reported. Copper is incorporated, and coordination occurs by the two imidazole and one carboxylate group offered by the ligand. Depending on the oxidation state, it can adopt different coordination modes, as evidenced by the solid-state structures and computational investigation. The copper(I) state readily reacts with dioxygen and thereby undergoes CH activation. Moreover, the catalytic aerobic oxidation of hydroquinones as ubiquinol mimics is shown. Clean one-electron oxidation occurs under mild conditions and EPR analysis of the copper(II) state in the presence of water reveals striking similarities to the data obtained from pMMO., (© 2022 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

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 Pd II . Despite the subvalent nitrene character, selective C-H insertion with aldehydes follows nucleophilic selectivity. Transamidation of the benzamide product is enabled by reaction with N 3 SiMe 3 . 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., (© 2021 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

An azide masked amine is used to obtain a cage of lower symmetry that possess one terpy-group in an exo -position. This group can coordinate to iron(ii), yielding selectively an easy to purify Fe(terpy-cage) 2 dumbbell. The dumbbell can also be obtained in a one pot reaction, which proceeded without isolation of the exo -functionalized cage., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

A conceptual approach for the synthesis of quasi-heteroleptic complexes with properly endo-functionalized cages as ligands is presented. The cage ligand reported here is of a covalent organic nature, it has been synthesized via a dynamic combinatorial chemistry approach, making use of a masked amine. Inspired by enzymatic active sites, the described system bears one carboxylate and two imidazole moieties as independent ligating units through which it is able to coordinate to transition metals. Analysis of the iron(II) complex in solution and the solid state validates the structure and shows that no undesired but commonly observed dimerization process takes place. The solid-state structure shows a five-coordinate metal center with the carboxylate bidentately bound to iron, which makes Fe@2 an unprecedentedly detailed structural model complex for this kind of non-heme iron oxygenases. As, as confirmed by the crystal structure, sufficient space for other organic ligands is available, the biologically relevant ligand α-ketoglutarate is implemented. We observe biomimetic reaction behavior towards dioxygen that opens studies investigating Fe@2 as a functional model complex., (© 2021 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

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 Cp tt ReO 3 as a new catalyst (Cp tt =1,3-di- tert -butylcyclopentadienyl). The DODH reaction was optimized using 2 mol % of Cp tt ReO 3 and 3-octanol as both reductant and solvent. The Cp tt ReO 3 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 Cp tt ReO 3 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., Competing Interests: The authors declare no conflict of interest.

A cobalt-porphyrin catalyst encapsulated in a cubic M8 L6 cage allows cyclopropanation reactions in aqueous media. The caged-catalyst shows enhanced activities in acetone/water as compared to pure acetone. Interestingly, the M8 L6 encapsulated catalyst reveals size-selectivity. Smaller substrates more easily penetrate through the pores of the "molecular ship-in-a-bottle catalysts" and are hence converted faster than bigger substrates. In addition, N-tosylhydrazone sodium salts are easy to handle reagents for cyclopropanation reactions under these conditions., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

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 (M(II)(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 Co(II)(TPyP) complex is significantly increased compared to free Co(II)(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., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)