Preparation, structure, and reactivity of ortho-hydroxy-substituted aryliodonium salts, precursors to ortho-iodo-substituted diaryl ethers

ortho-Hydroxy-substituted aryliodonium salts were prepared by a two-step one-pot synthesis based on the reaction of 2-alkoxy-1-[(diacetoxy)iodo]arenes with arylboronic acids involving the initial formation of 2alkoxyphenyl(aryl)iodonium salts and followed by deprotection of the intermediate product by boron tribromide.This procedure works well with halogen-, cyano-, 2-hydroxy-, 3-hydroxy-, 4-hydroxy-, methyl-, or trifluoromethyl-substituted arylboronic acids.Structures of three 2-hydroxyphenyl(aryl)iodonium bromides were confirmed by single crystal X-ray crystallography.The prepared 2-hydroxyphenyl(aryl)iodonium salts can be further converted to ortho-iodo-substituted diaryl ethers by treatment with a base via intermediate formation of the unstable aryliodonium betaines.R I + OH 13 examples X-ray for R = H, 2-Cl, and 4-OH Br - R O I I OMe AcO OAc K 2 CO 3 (10 eq.) R B(OH) 2 1) 2) BBr 3