Diazo Ethers: Formation and Decomposition in the Course of Reactions Between Arenediazonium Ions and Different Alcohols

The present review is aimed to summarize recent research on the O-coupling reactions of arenediazonium, ArN2 +, ions with different alcohols under acidic conditions. Encapsulating in a nutshell their mechanisms, it appears that two possible products may be formed depending on experimental conditions, namely a highly unstable aryl cation, Ar+, that yields substitution products and a reactive diazo ether, namely Ar-N=N-O-R, which initiates a radical mechanism through the formation of aryl radicals Ar• to yield reduction products.