Metal-free synthesis of 1, N 6 -ethenoadenines from N 6 -propargyl-adenines via NIS mediated radical cascade reaction.

In the present paper, an efficient approach for the construction of 1, N 6 -ethenoadenines from conveniently prepared N 6 -propargyl-adenines is developed. This reaction merges N -iodosuccinimide radical initiation and aerobic aminooxygenation in dioxane. This mild, 5-exo-dig , and metal-free cascade reaction could be applied to a wide substrate scope to provide 1, N 6 -ethenoadenines in moderate to good yields. The reaction mechanism was proposed and tested using radical inhibitor (butylated hydroxytoluene) and isotopic labelling ( 18 O 2 ) experiments.