ACS Organic & Inorganic Au最新文献

The integration of fluorine into medicinal compounds has become a widely used strategy to improve the biochemical and therapeutic properties of drugs. Inclusion of -CF₂H and -OCF₃ fluoroalkyl groups has garnered attention due to their bioisosteric properties, enhanced lipophilicity, and potential hydrogen-bonding capability in bioactive substances. In this study, we prepared a series of stable Cu[CF(OCF₃)(CF₂H)]L _n complexes by insertion of commercially available perfluoro(methyl vinyl ether), CF₂=CF(OCF₃), into Cu-H bonds derived from Stryker's reagent, [CuH(PPh₃)]₆, using ancillary ligands L. Notably, certain of these complexes effectively transfer the fluoroalkyl group to aroyl chlorides. Through reaction optimization and computational analysis, we identified dimethylsulfoxide as a pivotal coligand, playing a distinctive role in enabling the fluoroalkylation of a range of aroyl chlorides and aryl iodides. The latter also benefits from addition of CuBr to abstract PPh₃, generating solvent-stabilized Cu[CF(OCF₃)(CF₂H)]. These methodologies allow for the introduction of geminal -OCF₃ and -CF₂H groups in a single transformation.

The integration of fluorine into medicinal compounds has become a widely used strategy to improve the biochemical and therapeutic properties of drugs. Inclusion of −CF₂H and −OCF₃ fluoroalkyl groups has garnered attention due to their bioisosteric properties, enhanced lipophilicity, and potential hydrogen-bonding capability in bioactive substances. In this study, we prepared a series of stable Cu[CF(OCF₃)(CF₂H)]L_n complexes by insertion of commercially available perfluoro(methyl vinyl ether), CF₂═CF(OCF₃), into Cu–H bonds derived from Stryker’s reagent, [CuH(PPh₃)]₆, using ancillary ligands L. Notably, certain of these complexes effectively transfer the fluoroalkyl group to aroyl chlorides. Through reaction optimization and computational analysis, we identified dimethylsulfoxide as a pivotal coligand, playing a distinctive role in enabling the fluoroalkylation of a range of aroyl chlorides and aryl iodides. The latter also benefits from addition of CuBr to abstract PPh₃, generating solvent-stabilized Cu[CF(OCF₃)(CF₂H)]. These methodologies allow for the introduction of geminal −OCF₃ and −CF₂H groups in a single transformation.

The first-coordination sphere of catalysts is known to play a crucial role in reaction mechanisms, but details of how equatorial ligands influence the reactivity remain unknown. Heteroatom ligated to the equatorial position of iron centers in nonheme iron metalloenzymes modulates structure and reactivity. To investigate the impact of equatorial heteroatom substitution on chlorite oxidation, we synthesized and characterized three novel mononuclear nonheme iron(II) complexes with a pentadentate bispidine scaffold. These complexes feature systematic substitutions at the equatorial position in the bispidine ligand framework where the pyridine group is replaced with NMe₂, SMe, and OMe groups. The three iron(II)–bispidine complexes were subjected to studies in chlorite oxidation reactions as a model pathway for oxygen atom transfer. Chlorine oxyanions, which have the halide in an oxidation state ranging from +1 to +7, have numerous applications but can contaminate water bodies, and this demands urgent environmental remediation. Chlorite, a common precursor to chlorine dioxide, is of particular interest due to the superior antimicrobial activity of chlorine dioxide. Moreover, its generation leads to fewer harmful byproducts in water treatment. Here, we demonstrate that these complexes can produce chlorine dioxide from chlorite in acetate buffer at room temperature and pH 5.0, oxidizing chlorite through the in situ formation of high-valent iron(IV)–oxo intermediates. This study establishes how subtle changes in the coordination sphere around iron can influence the reactivity.

Metal complexes with t-Bu-substituted allyl ligands are relatively rare, especially compared to their conceptually similar trimethylsilyl-substituted analogs. The scarcity partially stems from the few general synthetic entry points for the t-Bu versions. This situation was studied through a modified synthesis for the allyl ligand itself and by forming several mono(allyl)nickel derivatives. After 2,2,6,6-tetramethyl-4-hepten-3-one was converted to the related 5-bromo-2,2,6,6-tetramethylhept-3-ene (A^2tBr), a mixture of Ni(COD)₂ and A^2tBr in the presence of a neutral donor ligand such as MeCN was found to produce the dark red dimeric π-allyl complex [{A^2tNiBr}₂]. Both NMR and X-ray crystallographic data confirmed that the t-Bu substituents are in a syn, syn-conformation, like that in the previously described [{A′NiBr}₂] (A′ = 1,3-(TMS)₂C₃H₃) complex. [{A^2tNiBr}₂] will form adducts with neutral donors such as PPh₃ and IMes (IMes = 1,3-dimesitylimidazol-2-ylidene), but the resulting [A^2tNi(PPh₃)Br] complex is not as stable as its trimethylsilyl analog. The [A^2tNi(IMes)Br] complex crystallizes from hexanes as a monomer, with an η³-coordinated [A^2t] ligand, and in contrast to the starting arrangement in [{A^2tNiBr}₂], the t-Bu groups on the A^2t ligand are in a syn, anti-relationship. This structure is paralleled in the trimethylsilyl analog [A′Ni(IMes)Br]. DFT calculations were used to compare the structures of t-Bu- and related trimethylsilyl-substituted complexes.

Anion-exchange membranes (AEMs), known for enabling the high conductivity of hydroxide anions through dense polymeric structures, are pivotal components in fuel cells, electrolyzers, and other important electrochemical systems. This paper unveils an unprecedented utilization of AEMs in an electrochemical oxygen separation process, a new technology able to generate enriched oxygen from an O₂/N₂ mixture using a small voltage input. We demonstrate a first-of-its-kind AEM-based electrochemical device that operates under mild conditions, is free of liquid electrolytes or sweep gases, and produces oxygen of over 96% purity. Additionally, we develop and apply a one-dimensional time-dependent and isothermal model, which accurately captures the unique operational dynamics of our device, demonstrates good agreement with the experimental data, and allows us to explore the device’s potential capabilities. This novel technology has far-reaching applications in many industrial processes, medical oxygen therapy, and other diverse fields while reducing operational complexity and environmental impact, thereby paving the way for sustainable on-site oxygen generation.