An I2-mediated aerobic oxidative annulation of amidines with tertiary amines via C-H amination/ C-N cleavage for the synthesis of 2,4-disubstituted 1,3,5-triazines

An iodine-mediated formal oxidative cycloaddition of amidines with tertiary amines was first demonstrated in air. Both symmetrical and unsymmetrical 2,4-disubstituted 1,3,5-triazines were obtained in up to 85% yields. It is noted that a tertiary amine was employed as a one carbon synthon of 1,3,5-triazines and two C-N bonds were formed in one pot. Control experiments revealed that the reaction underwent a radical pathway promoted by I+. The method is transition-metal-free, peroxide-free, and operationally simple to implement with a wide scope of substrates.