Reductive Cleavage Mechanism of Diphenyl Ether and Apparent Ipso Trapping of an Intermediate Radical Anion with a Silyl Ether

Article abstract of DOI:10.1021/jo00143a014

Chemical evidence for a radical anion mechanism in the case of reductive cleavage of diphenyl ether under Na/HMPA conditions is reported.The product phenyl radical abstracts a hydrogen atom instead of successive capture of an electron.Other ethers (dibenzyl, benzyl phenyl, and methyl phenyl) are also cleaved under these reductive conditions.The initially formed radical anion of diphenyl ether is apparently largely trapped before cleavage by trimethylsilyl ethers leading ultimately to ipso phenyl substitution.The mechanism of ipso substitution is discussed.