Xenon difluoride in the organic laboratory: a tale of substrates, solvents and vessels

Abstract

This Account summarises a series of studies of the reactions of xenon difluoride with organic substrates. It is concluded that xenon difluoride has two initial modes of reaction with organic substrates: single electron transfer (SET) and electrophilic addition. Reactions of aryltrimethylsilanes, carboxylic acids and esters, and trimethylsilyl enol ethers are discussed. The mode of reaction is determined by a combination of the solvent, the reaction vessel material and the presence of an acid catalyst. Pyrex, in the form of a flask surface, is a very effective catalyst for electrophilic reactions but this effect is inhibited by use of acetonitrile as solvent. Trimethylsilyl derivatives are particularly convenient substrates as these avoid the formation of HF, which may catalyse side-reactions. Some studies using [ 18 F]-XeF 2 are described.

The influence of electronegativity on linear and triangular three-centre bonds

“…Table 2. Electronegativity differences (Δ XY ) between Y and X in molecules X-Y-X In contrast to Kr, 17 and Xe, 18,19 the difluoride of argon has not been reported. The Δ XY value of 0.95 (Table 2, Entry 4) implies that ArF 2 will be significantly less stable then KrF 2 .…”

Vessel effects in organic chemical reactions; a century-old, overlooked phenomenon

“… 97 The results have recently been described in an account reviewing their results in detail and giving an extended overview of the influence of vessel material and solvents on the outcome of reactions with XeF 2 . 98 …”

Strategy for Selective Csp2–F and Csp2–Csp2 Formations from Organoplatinum Complexes

“…23 It has limited lifetime in various common organic solvents and different type of vessels. 24 Also, it is a hazardous compound in a way that it is corrosive to exposed tissues and releases toxic compounds in contact with moisture (MSDS: xenon difluoride). So, all these limitations and precautions for using this compound even in lab scale make it an inappropriate candidate for usual reagent in common chemical transformation.)…”