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

2013 ARKIVOC  
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
more » ... sence 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. Molecules associated with [3c-4e] bonds cannot be fully represented by conventional 2-centre, 2electron [2c-2e] covalent bonds and are usually represented by dipolar or hypervalent structures. Examples commonly encountered in organic chemistry are 1,3-dipoles and hypervalent reagents of Group 15-18 elements. 1,3-Dipoles are usually represented by dipolar structures of the general Reviews and Accounts ARKIVOC 2014 (i) 109-126
doi:10.3998/ark.5550190.p008.436 fatcat:kvgdjy4qazhtphzzujdvnfulvq