A cobalt-(salen)-catalyzed γ-C-H hydrazination of alcohols is unveiled, merging a double hydrogen atom transfer (HAT) and a proton-coupled electron transfer (PCET) within a single catalytic cycle. The transformation harnesses metal-hydrogen atom transfer-induced radical translocation and electrophilic azodicarboxylate coupling to achieve remote C-H functionalization under mild and sustainable conditions. Mechanistic investigations (EPR, UV-vis, and spin-trapping) reveal cobalt oxidation state modulation and transient radical intermediates, while DFT analysis elucidates the double HAT/PCET pathway and site selectivity. This strategy offers an efficient and sustainable route from simple alcohols to γ-hydrazino and γ-amino alcohols.

Three bisphosphine ligands based on propargyl-type alkyne complexes [Tp*W(CO)(OR){eta 2-C2(CH2PPh2)(PPh2)}] {Tp* = hydridotris(3,4,5-trimethylpyrazolyl)borate} with R = Me, Et, i Pr have been synthesized and characterized. The pK b values of the two phosphine groups were determined by conversion into the selenide derivative and determination of the 31P/77Se coupling constants. The methoxy-substituted compound was utilized as a metalla-ligand for preparation of a dinuclear bisphosphine kappa 2-PdCl2 complex. The electrochemical properties were investigated using cyclic voltammetry (CV) and IR spectroelectrochemistry (IR-SEC). The CV experiments of both the ligand and the Pd complex showed an electrochemically reversible W(II/III) redox couple, indicating that the W(III) species is stable on the voltammetry timescale. However, in both cases, IR-SEC measurements disclosed a follow-up process upon oxidation, showing that the W(III) compound undergoes a fast chemical transformation. Pure component decomposition of the IR-SEC data was performed for kinetic analysis of the reaction profile. IR and mass spectrometric monitoring after stoichiometric oxidation as well as DFT calculations point to the formation of a [W=O] moiety by cleavage of the methoxy group leading to a subsequent disproportionation equilibrium.

We report the epoxidation of Cashmeran followed by a domino Baeyer‐Villiger oxidation and a previously unrecognized acid‐catalyzed rearrangement, furnishing a novel α‐carbonyl δ‐spirolactone. Nuclear Magnetic Resonance (NMR) spectroscopic studies and single crystal X‐ray diffraction analysis confirmed the formation of the δ‐spirolactone. Furthermore, the proposed reaction mechanism was investigated by computational methods supporting a stereoselective transannular transesterification as key step in the formation of the novel δ‐spirolactone.

The growing importance of polyethylene furanoate (PEF) as a potential biobased substitute for PET is sparking interest in developing strategies for the chemical recycling of PEF. Access to appropriate model compounds is desirable for the development of depolymerization methods as well as for studying molecular properties and reactivity of PEF models. Herein, we describe a bottom-up strategy for the efficient and selective preparation of specific chain fragments from 2,5-furandicarboxylic acid (FDCA) and monoethylene glycol (MEG). Since conventional esterification methods according to Fischer and Steglich proved to be ineffective for certain target compounds, a sequence that consists of one-sided FDCA protection, Mukaiyama esterification, and subsequent deprotection was developed. The strategy was successfully applied to the preparation of various model compounds, including examples that have not yet been described in the literature.

The heterodinuclear zirconocene/titanocene complexes, [Cp2Zr(μ-Me)(μ-C2R)(TiCp2)] where R = SiMe3 and R = Ph, were prepared using the previously reported comproportion reaction of the zirconocene alkynyl methyl complex with Rosenthal's zirconocene source. Examination of the molecular structure revealed alkynyl group migration from Zr to Ti, as confirmed by single-crystal x-ray analysis, nuclear magnetic resonance spectroscopy, and quantum chemical calculations. The homodinuclear (Zr/Zr) and heterodinuclear (Ti/Zr) complexes were activated with [Ph3C][B(C6F5)4], B(C6F5)3, and a mixture of B(C6F5)3 with excess Et3SiH (SiHB system) as aluminium-free activators and tested in ethylene polymerization. Depending on the type of activator, unique reactivity was observed, resulting in either electron or methyl abstraction and the formation of cationic species. The catalytically active species are proposed to have dinuclear character, forming linear polyethylenes with unsaturated groups predominantly on the Zr cationic center. In contrast, the Ti cationic center generated by a SiHB system only in dichloromethane produced silicon-terminated polyethylenes.

The title compound, C27H27NP2, is a new potential asymmetric P,P,N ligand and consists of a diphenylphosphino and a tert-butyl(pyridin-2-yl)phosphino group bridged by a 1,2-phenylene backbone. The dihedral angles between the central and pendant aromatic rings are 83.07 (6), 85.99 (5) and 82.80 (6)°. In the extended structure, weak C—H...π interactions link the molecules.

The title compound, C27H27NP2, is a new potential asymmetric P,P,N ligand and consists of a di-phenyl-phosphino and a tert-but-yl(pyridin-2--yl)phosphino group bridged by a 1,2-phenyl-ene backbone. The dihedral angles between the central and pendant aromatic rings are 83.07 (6), 85.99 (5) and 82.80 (6)°. In the extended structure, weak C-H⋯π inter-actions link the mol-ecules.

The dinuclear title compound [(Cp2Zr)2(μ-Me)(μ-C2Ph)] 5 was prepared from a zirconocene alkynyl methyl complex and Rosenthal's zirconocene source [Cp2Zr(py)(η2-Me3SiC2SiMe3)] in a formal comproportionation reaction. This complex shows catalytic activity for the dehydrocoupling of amine boranes, with a dinuclear hydride-bridged alkynyl complex 6 being formed as a catalytically relevant species. The structure of this complex was confirmed for the first time by single-crystal X-ray analysis. The reaction of complex 5 with hydrogen results in hydrogenation of the alkynyl ligand, yielding a highly labile trinuclear hydride-bridged complex as a possible intermediate of zirconocene dihydride/ethylbenzene formation. This complex shows an unusual distorted planar tetracoordinate environment at the central carbon atom positioned between the three Zr centers. The reaction of complex 5 with 2-cyanopyridine and acetonitrile is characterized by a reduction of the substrates. The herein reported reactivity of complex 5 demonstrates the remarkable potential of well-established dinuclear zirconocenes to stabilize unusual bond situations, which were analyzed comprehensively using spectroscopic, structural, and computational methods.

The title compound, [Ru(C47H51O6P3)(C4H6)]·0.5C4H10O, consists of an RuII atom coordinated by 1,1,1-tris{[bis(4-methoxyphenyl)phosphanyl]methyl}ethane in κ3-coordination mode and an η4-coordinating trimethylenemethane ligand. The complex molecule is co-crystallized with a diethyl ether solvent molecule. A half diethyl ether molecule was considered, whereas additional disordered solvent molecules were removed from the diffraction data with the SQUEEZE procedure in PLATON [Spek (2015). Acta Cryst. C71, 9–18].

The solvated title compound, [Pd(C5H5NO2)(C28H38N2O2P2)]·0.5C7H8, consists of a palladium(0) atom coordinated by a chelating α,α′-bis[(tert-butyl)(6-methoxypyridin-2-yl)phosphino]o-xylene ligand and an η2-coordinating N-methylmaleinimide molecule to generate a 16 electron complex in which the metal atom has a pseudo-square-planar coordination environment. The co-crystallized toluene solvent molecule is disordered about an inversion centre by symmetry. Weak C—H...O and C—H...N hydrogen bonds connect the components in the extended structure.

Isomerization of C-C double bonds is an efficient tool for converting bulk olefins into high-value compounds. Herein we describe a newly developed homogeneous cobalt-based system which enables the isomerization of allylamines to enamines with similar activity and selectivity to noble metal catalysts. The catalyst activity was bound to the presence of furan-2-yl substituents of the phosphine ligand, while the selectivity was increased with the number of benzofuran-2-yl groups. The resulting cobalt(0) catalysts allowed the isomerization of various aliphatic and aromatic allylamines, including the synthesis of industry-relevant products with high catalytic activity. Potential industrial application of our system was substantiated by the scale-up experiment, which provided 311 g of citronellal in 96% yield. We proposed a plausible mechanism based on EPR and NMR analysis combined with deuterium labeling, radical trapping experiments, and kinetic studies.

Starting from the alkyne complex Cp2Zr(py)(η2-Me3SiC2SiMe3) (Cp = η5-cyclopentadienyl, py = pyridine), the synthesis and complete characterisation of a zirconocene(IV) triazenido hydride complex and its use in the activation of small molecules is reported. The reaction with CO2 led to the formation of a zirconocene(IV) triazenido-formate complex, which was further investigated for its stability towards different bases with respect to the formation of formic acid. The experimentally observed reaction pathway was investigated computationally using DFT methods, revealing the favourable role of pyridine coordination in the hydrogen transfer from the triazene to the alkyne unit of the zirconocene reagent.

A new electron-rich, bidentate phosphine, 1,2-bis­[di­(benzo­furan-2-yl)phosphan­yl]ethane, was synthesized and structurally characterized by single-crystal X-ray diffraction.

A new class of amino acids, so-called fatty amino acids, which integrate the typical structural motif of another important class of natural products, fatty acids, is presented. By applying palladium-catalyzed amidocarbonylation, diverse new N-acyl fatty amino acids are synthesized in one step in a 100% atom-efficient manner. Utilizing a small amount (0.5 mol%) of simple commercial Pd(OAc)2, the desired products can be synthesized in good to high yields, up to multi-g-scale. The shown products represent a combination of two essential classes of natural products and provide new bio-based building blocks with potential for many applications.

The title compound, C34H24O4P2, consists of an ethylene-bridged diphosphine with benzofuran residues, where the P—C—C—P backbone exhibits an anti-conformation. The asymmetric unit contains one half molecule, which is completed by inversion symmetry.

The title compound, C9H8BrClO, crystallizes in the monoclinic space group P21/n with four molecules in the unit cell. The molecular structure consists of almost planar molecules with the chlorine atom protruding from this plane.

The dinuclear title compound [(Cp 2 Zr) 2 ( μ ‐Me)( μ ‐C 2 Ph)] 5 was prepared from a zirconocene alkynyl methyl complex and Rosenthal's zirconocene source [Cp 2 Zr(py)( η 2 ‐Me 3 SiC 2 SiMe 3 )] in a formal comproportionation reaction. This complex shows catalytic activity for the dehydrocoupling of amine boranes, with a dinuclear hydride‐bridged alkynyl complex 6 being formed as a catalytically relevant species. The structure of this complex was confirmed for the first time by single‐crystal X‐ray analysis. The reaction of complex 5 with hydrogen results in hydrogenation of the alkynyl ligand, yielding a highly labile trinuclear hydride‐bridged complex as a possible intermediate of zirconocene dihydride/ethylbenzene formation. This complex shows an unusual distorted planar tetracoordinate environment at the central carbon atom positioned between the three Zr centers. The reaction of complex 5 with 2‐cyanopyridine and acetonitrile is characterized by a reduction of the substrates. The herein reported reactivity of complex 5 demonstrates the remarkable potential of well‐established dinuclear zirconocenes to stabilize unusual bond situations, which were analyzed comprehensively using spectroscopic, structural, and computational methods.

The title compound, 3-chloro-propio-phenone (or 3-chloro-1-phenyl-propan-1-one), C9H9ClO, consists of an almost planar mol-ecule that is charaterized by very small torsion angles within the alkyl side chain (torsion angles < 6.3°). No hydrogen bonds are observed in the crystal packing. The compound exhibits a melting point of 54°C.

The title compound, 3-chloro­propio­phenone C9H9ClO, consists of an almost planar mol­ecule that is charaterized by very small torsion angles within the alkyl side chain (torsion angles < 6.3°).

The title compound, C9H8BrClO, crystallizes in the monoclinic space group P21/n with four mol-ecules in the unit cell. The mol-ecular structure consists of almost planar mol-ecules with the chlorine atom protruding from this plane.