Modern pentafluorosulfanyl (SF5) chemistry has an Achilles heel: synthetic accessibility. Herein, we present the first approach to aryl‐SF4Cl compounds (key intermediates in state‐of‐the‐art aryl‐SF5 synthesis) that overcomes the reliance on hazardous fluorinating reagents and/or gas reagents (e.g. Cl2) by employing easy‐to‐handle trichloroisocyanuric acid, potassium fluoride, and catalytic amounts of acid. These simple, mild conditions allow direct access to aryl‐SF4Cl intermediates that either have not been or cannot be demonstrated using previous methods. Furthermore, the same approach provides access to aryl‐SF3 and aryl‐SeF3 compounds, which extend the applications of this chemistry beyond arene SF5‐functionalization, and demonstrate its ability to address a more general oxidative fluorination problem.

The TeF5 group is significantly underexplored as a highly fluorinated substituent on an organic framework, despite it being a larger congener of the acclaimed SF5 group. In fact, only one aryl‐TeF5 compound (phenyl‐TeF5) has been reported to date, synthesized using XeF2. Our recently developed mild TCICA/KF approach to oxidative fluorination provides an affordable and scalable alternative to XeF2. Using this method, we report a scope of extensively characterized aryl‐TeF5 compounds, along with the first SC‐XRD data on this compound class. The methodology was also extended to the synthesis and structural study of heretofore unknown aryl‐TeF4CF3 compounds. Additionally, preliminary reactivity studies unveiled some inconsistencies with previous literature regarding phenyl‐TeF5. Although our studies conclude that the arene‐based TeF5 (and TeF4CF3) group is not quite as robust as the SF5 group, we find that the TeF5 group is more stable than previously thought, thus opening a door to explore new applications of this motif.

The crystal structures of different perfluoroorganyl iodanes are described, including those of four new benziodoxole derivatives with RF = n‐C3F7, n‐C4F9, n‐C8F17, and C6F5. In all of the compounds, the iodine atom shows significant Lewis acidity, and the fourth coordination site is readily filled by secondary bonding interactions to produce square‐planar coordination. Although this geometry is a good model for benziodoxoles, benziodoxolone derivatives tend to aggregate further through additional weak I···O or I···aryl contacts. The different interactions lead to the formation of various assemblies with different dimensions in the solid state. The protonation of the reagents results in the formation of entirely different supramolecular structures, which are supported by hydrogen bonding. The structural features of the reagents in the solid state reflect well their behavior in solution, and the I–C(RF) bond is influenced by the coordination of Lewis basic solvents to the iodine atom and by hydrogen bonding with protic solvents. These solvent effects are more pronounced for reagents containing the trifluoromethyl fragment than for derivatives with longer RF chains.

Moderne Pentafluorosulfanyl(SF5)‐Chemie hat eine entscheidende Schwachstelle: synthetische Zugänglichkeit. In dieser Arbeit präsentieren wir die erste Methode für die Herstellung von Aryl‐SF4Cl‐Verbindungen (Schlüsselintermediate für die Aryl‐SF5‐Synthese), die durch Einsatz von einfach zu handhabender Trichlorisocyanursäure, Kaliumfluorid und katalytischer Mengen an Säure, ohne die Verwendung von gefährlichen Fluorierungsmitteln und oder Gasen als Reaktanden, auskommt. Diese simplen, milden Bedingungen erlauben den direkten Zugang zu Aryl‐SF4Cl‐Intermediaten die mit bisherigen Methoden entweder noch nicht synthetisiert wurden oder nicht synthetisiert werden konnten. Des Weiteren eröffnet diese Methode den Zugang zu Aryl‐SF3‐ und Aryl‐SeF3‐Verbindungen, was die Anwendung dieser Chemie über die Grenzen der SF5‐Funktionalisierung hinaus erweitert und somit eine Lösung zum komplexen Problem der oxidativen Fluorierung anbietet.

This mild TCICA/KF oxidative fluorination approach provides controllable access to aryl-IF2 and aryl-IF4 compounds, thus allowing detailed structural studies.