Die SF₅‐Gruppe zugänglicher gemacht: Eine gasfreie Synthese von Aryl‐Tetrafluor‐λ⁶‐Sulfanyl‐Chloriden

Abstract

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.

Improved Access to Organo‐Soluble Di‐ and Tetrafluoridochlorate(I)/(III) Salts

“…Consequently, we avoided the isolation of larger quantities of [NEt Trifluoromethyl and pentafluorosulfanyl derivatives have a growing importance in pharmaceutical-and agrochemistry. [23,24,25] Recently, Togni and co-workers reported on a non-gaseous reagent to access aryl tetrafluorido-l 6 -sulfanyl chlorides (Ar-SF 4 Cl), a key intermediate for the synthesis of pentafluorosulfanyl aryls (Ar-SF 5 ). [24] Beier and co-workers recently studied the direct fluorination with dilute elemental fluorine and disulfides to directly obtain pentafluorosulfanyl aryls, a process with industrial application.…”

“…[23,24,25] Recently, Togni and co-workers reported on a non-gaseous reagent to access aryl tetrafluorido-l 6 -sulfanyl chlorides (Ar-SF 4 Cl), a key intermediate for the synthesis of pentafluorosulfanyl aryls (Ar-SF 5 ). [24] Beier and co-workers recently studied the direct fluorination with dilute elemental fluorine and disulfides to directly obtain pentafluorosulfanyl aryls, a process with industrial application. [25] As a proof of concept we exposed diphenyl disulfide, Ph 2 S 2 , to a solution of [NEt 3 Me][ClF 4 ] in propionitrile at À50 8C to directly obtain phenylsulfur pentafluoride, PhSF 5 .…”

Chemoselective Hydro(Chloro)pentafluorosulfanylation of Diazo Compounds with Pentafluorosulfanyl Chloride

“…The resulting solution of SF 5 Cl in n ‐hexane could be stored on the bench for months without noticeable decomposition. Finally, the reaction was easily scaled up in an average yield of 47 % from 0.46 mmol [14] to 32 mmol.…”

Chemoselective Hydro(Chloro)pentafluorosulfanylation of Diazo Compounds with Pentafluorosulfanyl Chloride

“…[13] Togni observed the formation of SF 5 Cl from the mixture of sulfur powder, dry KF, and trichloroisocyanuric acid (TCCA) in MeCN using trifluoroacetic acid (TFA) as the catalyst. [14] Although Tognis protocol is very intriguing in terms of gasreagent-free conditions, neither the yield nor purification process of SF 5 Cl was provided. To develop a synthetically useful method in common research laboratories, we optimized Tognis procedure (Scheme 1).…”