Elemental Fluorine and HOF·CH₃CN in Service of General Organic Chemistry

Abstract

At present, HOF·CH3CN complex is the best oxygen transfer agent that chemistry has to offer. It is readily made by passing dilute fluorine through aqueous acetonitrile and does not require any isolation or purification. It is stable in aqueous acetonitrile solution for a few hours at room temperature, providing ample opportunities for various reactions. Epoxidation of regular olefins as well as of very electron‐depleted ones proceeds smoothly. HOF·CH3CN transfer oxygen also to heteroatoms, especially sulfur and nitrogen. Even very electron‐depleted sulfides such as RfSAr that are very difficult to oxidize, are converted into the respective sulfones in a matter of minutes. On the other hand, since the reaction conditions are very mild, the reagent can oxidize various thiophenes and amino acids to the corresponding S,S‐dioxides and α‐nitro acid derivatives. HOF·CH3CN was also instrumental in ending the 50 years quest for making the elusive 1,10‐phenanthroline N,N‐dioxide and for the novel transformation of azides to nitro derivatives. The use of BrF3 for making symmetric esters and of tBuOF as an electrophilic tert‐butoxylation agent is also mentioned. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

Elemental fluorine in organic chemistry (1997–2006)

“…This review will cover published literature concerning the use of elemental fluorine for the synthesis of carbon-fluorine bonds in organic systems over the period 1997-2006, updating our earlier review [8] on this subject in a similar format and complementing other recent discussions in this area [9][10][11]. The fluorination of fullerenes has been reviewed [12,13] and will not be discussed here whilst the chemistry of reagents that are synthesised from fluorine, such as reagents of the N-F class [6,14] and HOF [15], is also beyond the scope of this review.…”

9.03 Organic Synthesis in Small Scale Continuous Flow: Flow Chemistry

“…One effective powerful oxidizing agent is HOF Á CH 3 CN, 68 which is formed by passing dilute fluorine gas into a solution of wet acetonitrile (20 v% water). The substrate is then typically added to this solution for oxidation.…”

Liquid phase oxidation chemistry in continuous-flow microreactors

“…326 However, having a half-life of approximately four hours at room temperature, the use HOF.MeCN in batch reactions is still underdeveloped. Since the complex should be produced 'on demand', Sandford et al considered that the implementation of microreactors could offer an effective way of generating and consuming HOF.MeCN in situ.…”