2-Azadienes 1 bearing a trialkylsilyloxy group on position 3 can be regarded as carboxylic acid synthons. Their cycloadditions with several classes of nitroso compounds have been studied in details as well as the transformation of the adducts into α-amino acids. This study showed that arylnitroso compounds such as nitrosobenzene reacted with 2-azadienes to give adducts that are potential precursors