Nitrous oxide as diazo transfer reagent.

Nitrous oxide, commonly known as "laughing gas", is formed as a by-product in several industrial processes. It is also readily available by thermal decomposition of ammonium nitrate. Traditionally, the chemical valorization of N 2 O is achieved via oxidation chemistry, where N 2 O acts as a selective oxygen atom transfer reagent. Recent results have shown that N 2 O can also function as an efficient diazo transfer reagent. Synthetically useful methods for synthesizing triazenes, N-heterocycles, and azo- or diazo compounds were developed. This review article summarizes significant advancements in this emerging field.