Activation of SF₆ at Platinum Complexes: Formation of SF₃ Derivatives and Their Application in Deoxyfluorination Reactions

Abstract

The activation of SF6 at [Pt(PR3)2] R=Cy, iPr complexes in the presence of PR3 led selectively and in an unprecedented reaction route to the generation of the SF3 complexes trans‐[Pt(F)(SF3)(PR3)2]. These can also be synthesized from SF4 and the SF2 derivative trans‐[Pt(F)(SF2)(PCy3)2][BF4] was characterized by X‐ray crystallography. trans‐[Pt(F)(SF3)(PR3)2] complexes are useful tools for deoxyfluorination reactions and novel fluorido complexes bearing a SOF ligand are formed. Based on these studies a process for the deoxyfluorination of ketones was developed with SF6 as fluorinating agent.

Activation of SF6 at a Xantphos-Type Rhodium Complex

“…Within this context, an efficient and controlled depletion of SF 6 under mild conditions is of current interest. ,,, An interesting approach consists of SF 6 degradation reactions at transition metal complexes. While SF 6 was degraded or recycled in the past decade mainly by adsorption, separation, and decomposition methods usually under harsh conditions, reports on the activation of SF 6 at transition metal complexes are still scarce. ,− , Degradation reactions of SF 6 are described at low-valent Ti, V, Cr, and Zr as well as at Fe and reduced Ni complexes. ,,, Sulfur-containing products were only identified in the reactions of SF 6 with [Cr­(C 5 Me 5 ) 2 ] and [Ti­(1,3- t Bu 2 C 5 H 3 )­(6,6-dmch)­(PMe 3 )] (6,6-dmch = 6,6-dimethylcyclohexadienyl) as well as with K 2 [(L t Bu Ni I ) 2 (μ–η 1 :η 1 -N 2 2– )] (L t Bu = [(HC­(C t BuNC 6 H 3 ( i Pr) 2 ) 2 ] − ), which yielded, among other compounds, [{Cr­(C 5 Me 5 )­(μ 2 -F)} 3 (μ 3 -S)] + [Cr­(C 5 Me 5 )­(F) 3 ] − , SPMe 3 or [(L t Bu Ni II ) 2 (μ-S)]. We previously reported on the activation of SF 6 at a binuclear rhodium complex as well as on the catalytic degradation of SF 6 to give phosphinesulfides and fluorosilanes with [Rh­(H)­(PEt 3 ) 4 ] in the presence of PEt 3 and silane. − Furthermore, it was demonstrated that SF 6 can be activated at [Pt­(PR 3 ) 2 ] (R = Cy, i Pr) complexes generating the SF 3 complex trans -[Pt­(F)­(SF 3 )­(PR 3 )]. , In addition, SF 6 was recently applied as a fluorinating agent, e.g., in a photoredox process for deoxyfluorination reactions using an iridium-based photocatalyst and diisopropylethyl amine as reductant to induce a fluorination of allylic alcohols. ,,,, Herein, we describe the reactivity of the pincer complex [Rh­(H)­{ t Bu xanPOP}] ( 1 ; t Bu xanPOP = 9,9-dimethyl-4,5-bis­(di tert -butylphosphino)-xanthene) toward SF 6 .…”

Non‐coordinated and Hydrogen Bonded Phenolate Anions as One‐Electron Reducing Agents

“…Clearly, methods for the successful degradation of sulfur hexafluoride are urgently required. Numerous papers are addressing SF 6 activation with transition metal complexes of titanium, [32] rhodium, [33] platinum, [34] chromium and vanadium, [35] as well as of nickel [36] . In all cases the principal reactions lead to corresponding sulfido and fluoride metal complexes.…”

Photoredox Catalytic α‐Alkoxypentafluorosulfanylation of α‐Methyl‐ and α‐Phenylstyrene Using SF6

“…In contrast, reports on non-toxic SF 6 in synthesis are rare although this would have strong environmental advantages. [9][10][11][12][13][14][15] SF 6 is still indispensable as an insulating gas in technical applications, like high-voltage gears, and as a protecting gas in the production of metals. SF 6 acts as an extremely potent greenhouse gas, [16] so the use of SF 6 as chemical reagent would be sustainable because the gas would be trapped and converted into potentially valuable chemical building blocks.…”