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Zinc carboxylate complexes are widely utilized as artificial models of metalloenzymes and as secondary building units of PCPs/MOFs. However, the relationship between the structure of the monodentate carboxylato ligand and the molecular arrangement of multinuclear zinc carboxylate complexes is not fully understood because of the coordination flexibility of the Zn ion and carboxylato ligands. Herein, we report the structural analysis of a series of complexes derived from zinc (meth)acrylate which has a linear infinite chain structure. The molecular structure of μ4‐oxido‐bridged tetranuclear complexes [Zn4(μ4‐O)(OCOR)6] revealed a distorted Zn4O core. Crystallization of zinc acrylate under aqueous conditions afforded a μ3‐hydroxido‐containing pentanuclear complex [Zn5(μ3‐OH)2(OCOR)8] as the repeating unit of an infinite sheet‐like structure in the solid state. It was also obtained by the hydrolysis of the μ4‐oxido‐bridged tetranuclear complex. In sharp contrast, the methacrylate analog retained the methacrylato ligands under aqueous crystallization conditions to form a macrocyclic dodecanuclear complex with methacrylato as the sole ligand. [ABSTRACT FROM AUTHOR]

Carbon‐fluorine bonds are stable and have demonstrated sluggishness against various chemical manipulations. However, selective transformations of C−F bonds can be achieved by developing appropriate conditions as useful synthetic methods in organic chemistry. This review focuses on C−C bond formation at monofluorinated sp3‐hybridized carbons via C−F bond cleavage, including cross‐coupling and multi‐component coupling reactions. The C−F bond cleavage mechanisms on the sp3‐hybridized carbon centers can be primarily categorized into three types: Lewis acids promoted F atom elimination to generate carbocation intermediates; nucleophilic substitution with metal or carbon nucleophiles supported by the activation of C−F bonds by coordination of Lewis acids; and the cleavage of C−F bonds via a single electron transfer. The characteristic features of alkyl fluorides, in comparison with other (pseudo)halides as promising electrophilic coupling counterparts, are also discussed. [ABSTRACT FROM AUTHOR]

This article discusses the synthesis of different shapes of complexes using zinc (meth)acrylate. The recrystallization of zinc methacrylate resulted in a macrocyclic dodecanuclear complex, while zinc acrylate formed a sheet-like pentanuclear core. Treating zinc (meth)acrylate with ZnO produced a tetranuclear complex. The article provides more detailed information on these findings. [Extracted from the article]

A simple and efficient methodology for the synthesis of 2-aryl-perfluorobenzoxazoles was developed via a direct dual C–F functionalization of perfluorobenzene with arylformamide in the presence of a Fe(II)/NaH/DMSO system. Various substituted aryl formamides are tolerated giving good yields. The preliminary fluorescence properties (up to 99% fluorescence quantum yield of 3d) of the products and their applications in the synthesis of uniform cubic platinum nanoparticles indicate that these perfluorobenzoxazole derivatives may have certain potential applications in materials chemistry. [ABSTRACT FROM AUTHOR]

3,5-Dimethylpyrazole (Pz*H) in well-defined Cp*RhIII (Cp* = 1,2,3,4,5-pentamethylcyclopentadienyl) complexes, or as an additive to [Cp*RhCl2]2 enhances catalytic activity in the dehydrogenation of dimethylamine-borane (DMAB) at room-temperature. Mechanistic studies indicate that the Lewis acidic RhIII-centre and dangling N-atom of the Pz* fragment operate cooperatively in accepting a hydride and proton from DMAB, respectively, leading directly to dimethylamino-borane and a RhIII–H complex. The rate limiting step involves protonation of the RhIII–H by the proximal NH fragment of the Pz*H moiety. [ABSTRACT FROM AUTHOR]

Changes in the photophysical properties of pyrene (Py)‐octafluoronaphthalene (OFN) co‐crystals (Py⋅OFN) upon mechanical stimuli are described herein. The Py⋅OFN co‐crystal showed a mechano‐induced bathochromic shift in emission, and a similar tendency was observed for the 1,3,6,8‐tetramethylpyrene‐OFN co‐crystal. These shifts are due to disruption of the microscopic molecular orientation in the co‐crystal, which allows for excimer formation. In sharp contrast to the parent Py⋅OFN and methyl‐substituted Py‐OFN co‐crystals, no mechano‐induced bathochromic shift was observed when longer alkyl chains were introduced to the 1‐, 3‐, 6‐, and 8‐positions of the Py chromophore. This photophysical opposability against mechanical stimuli could be explained by the orthogonally oriented alkyl groups on the Py ring, which existed between two Py cores like pillars. This fixed OFN to maintain the face‐to‐face alternatively stacked structure of the co‐crystal and thus prevented the formation of the Py excimer. The pillar effect demonstrated herein provides a rational design for co‐crystalline systems that are photophysically stable against mechanical stresses. [ABSTRACT FROM AUTHOR]

The relationship between the photophysical properties and molecular orientation of 1,3,6,8‐tetraalkylpyrenes in the solid state is described herein. The introduction of alkyl groups with different chain structures (in terms of length and branching) did not affect the photophysical properties in solution, but significantly shifted the emission wavelengths and fluorescence quantum yields in the solid state for some samples. Pyrenes bearing ethyl, isobutyl, or neopentyl groups at the 1‐, 3‐, 6‐, and 8‐positions showed similar emission profiles in both the solution and solid states. In contrast, pyrenes bearing other alkyl groups exhibited an excimer emission in the solid state, similar to that of the parent pyrene. On studying the photophysical properties in the solid state with respect to the obtained crystal structures, the observed solid‐state photophysical properties were found to depend on the relative position of the pyrene chromophores. The solid‐state photophysical properties can be controlled by the alkyl groups, which provide changing crystal packing. Among the pyrenes tested, 1,3,6,8‐tetraethylpyrene showed the highest fluorescence quantum yield of 0.88 in the solid state. [ABSTRACT FROM AUTHOR]

Glycoengineering strategy is applied for glucagon-like peptide 1 (7-36) amide (GLP-1) in order to improve its proteolytic stability and in vivo blood glucose-lowering activity. The effect of glycosylation on proteolytic resistance is examined by using synthetic glycopeptides having homogeneous glycoforms.

The article discusses a new approach, where in several zinc-catalyzed cycloisomerization reactions are conducted for the synthesis of different furans and furopyrimidine nucleosides. The methodology is shown to be extremely effective and advantageous, as it is inexpensive with small reaction time.

The tetranuclear zinc cluster [Zn.sub.4][(OCOC[F.sub.3]).sub.6]O as catalyst was used to develop a general and highly efficient transesterification method of various methyl esters. The Zn catalyst was found to have high tolerance of functional groups, low catalyst toxicity, and ease of operation.

Zn cluster-catalyzed transesterification reaction is used for developing a highly O-selective acylation in the presence of primary and secondary alkyl amines. The results have shown that the strategy of assembling metal ions as the core structure of an artificial enzyme has a high potential to increase reactivity as well as to change the azaphilic nature of late transition metals, leading to further enzyme-like chemoselective reactions.

We report herein a Rh(III)‐catalyzed oxidative coupling reaction of 2‐phenylpyridine derivatives with arylsilane reagents. In this reaction, AgF plays important roles as both oxidant and C−Si bond activator. Addition of the catalytic amount of pivalic acid was found to be the key to achieve high yields of the desired products in short reaction times. [ABSTRACT FROM AUTHOR]

Abstract: An iterative Ni‐catalyzed C(sp3)−C(sp3) cross‐coupling reaction of a novel cis‐cyclopropane containing bifunctional building blocks with alkyl halides and alkyl Grignard reagents enabled the introduction of a cyclopropane ring into the desired position(s) of saturated carbon frameworks, providing a straightforward synthetic route to cyclopropane fatty acids. The present method creates a direct route for the construction of saturated carbon frameworks, and can avoid the tedious multistep operations based on unsaturated functional group manipulations that are often employed in conventional synthetic routes. This method could be applicable to the synthesis of trans‐cyclopropane fatty acids and enantioenriched cyclopropane fatty acids. Formal synthesis of α‐mycolic acid was achieved by the C(sp3)−C(sp3) cross‐coupling reaction of cyclopropane‐containing bifunctional building blocks. [ABSTRACT FROM AUTHOR]

Cover Picture: Cross- and Multi-Coupling Reactions Using Monofluoroalkanes (Chem. Rec. 9/2023) Alkyl fluoride, C-F bond cleavage, cross-coupling reaction, multi-component coupling reaction, Friedel-Crafts reaction Keywords: alkyl fluoride; C-F bond cleavage; cross-coupling reaction; multi-component coupling reaction; Friedel-Crafts reaction EN alkyl fluoride C-F bond cleavage cross-coupling reaction multi-component coupling reaction Friedel-Crafts reaction 1 1 1 09/12/23 20230901 NES 230901 The cover picture shows concept of utilizing monofluoroalkanes for C-C bond formations by C-F bond cleavage, where the fluorine leaving group (blue hermit crab) exuberantly shifts toward a cationic reagent/catalyst (empty shell), and the remaining alkyl group (red shell) forms new C-C bond with an incoming nucleophilic coupling counterpart (red hermit crab). [Extracted from the article]

A Ni-catalyzed oxidative C–H/C–H cross-dehydrogenative coupling (CDC) reaction was developed for constructing various highly functionalized alkyl (aryl)-substituted thiophenes. This method employs thiophenes and aliphatic (aromatic) amides that contain an 8-aminoquinoline as a removable directing group in the presence of a silver oxidant. The approach enables the facile one-step synthesis of substituted thiophenes with high functional group compatibility via double C–H bond cleavage without affecting C–Br and C–I bonds. DFT calculations verify the importance of KH2PO4 as an additive for promoting C–H bond cleavage and support the involvement of a Ni(iii) species in the reaction. [ABSTRACT FROM AUTHOR]

Iron-catalyzed cross-coupling reaction of vinylic ethers with aryl Grignard reagents is described. The reaction proceeded at room temperature with catalytic amounts of an iron salt without the aid of costly ligands and additives. In this catalytic system, vinylic C−O bonds were preferentially cleaved over aromatic C−O bonds of aryl ethers or aryl sulfonates. [ABSTRACT FROM AUTHOR]

In the presence of a nickel catalyst, 1,3-butadiene undergoes selective dimerization and alkylarylation with alkyl fluorides and aryl Grignard reagents to give 1,6-octadienes with alkyl and aryl groups at the 3- and 8-positions, respectively, by the consecutive formation of three carbon-carbon bonds. The formation of an anionic nickel complex plays an important role in forming C−C bonds with alkyl fluorides. [ABSTRACT FROM AUTHOR]

Copper complexes generated in situ from CuCl2, alkyl Grignard reagents, and 1,3-dienes play important roles as catalytic active species for the 1,2-hydroalkylation of 1,3-dienes by alkyl fluorides through CF bond cleavage. The alkyl group is introduced to an internal carbon atom of the 1,3-diene regioselectively, thus giving rise to the branched terminal alkene product. [ABSTRACT FROM AUTHOR]

Copper complexes generated in situ from CuCl2, alkyl Grignard reagents, and 1,3-dienes play important roles as catalytic active species for the 1,2-hydroalkylation of 1,3-dienes by alkyl fluorides through CF bond cleavage. The alkyl group is introduced to an internal carbon atom of the 1,3-diene regioselectively, thus giving rise to the branched terminal alkene product. [ABSTRACT FROM AUTHOR]

ABSTRACT Decarbonylative rearrangement of seleno- and tellurocarbamates carrying an allenyl group on the nitrogen was found to proceed in the presence of a palladium catalyst to afford 3-chalcogeno-1-azadienes. This transformation may involve oxidative addition of Pd to a carbon-chalcogen bond, decarbonylation from a carbamoylpalladium unit (R2N-C(O)-PdChPh: Ch = Se or Te), Pd shift, and reductive elimination. [ABSTRACT FROM AUTHOR]