Synthesis,Characterization,and Reaction of Crown Ether Complexes of Aqua(hydroxy)(aryl)iodonium Ions

摘要

The Koser reagent,[hydroxy(tosyloxy)iodo]benzene (1;Ts = p-toluenesulfonyl),is a useful oxidizing agent for a range of organic substrates.It has been reported that upon dissolution in water the gamma~3-iodane undergoes complete ionization to give the hydroxy(phenyl)iodonium cation (PhI~+OH).The hydroxy(phenyl)iodonium ion does not form an ion pair with a tosylate ion and is presumed to be ligated with at least one water molecule at an apical site of the iodine(III) center.This aqua(hydroxy)(phenyl)iodonium ion 2 (L = H_2O) is highly soluble in water with a pK_a value of 4.30 at 20 deg C.