Base-free synthesis of 1,3,5-triazines via aerobic oxidation of alcohols and benzamidine over a recyclable OMS-2 catalyst

By using 4Na(2)SO(4)center dot 2H(2)O(2)center dot NaCl as a reductant, manganese oxide octahedral molecular sieve (OMS-2) with enhanced surface area and mixed valence was prepared successfully. OMS-2 showed excellent catalytic ability towards aerobic oxidative synthesis of 1,3,5-triazines from benzyl alcohols and benzamidine. Methyl benzenes, DMF and DMSO could also be employed as substrates to react with benzamidine offering triazines under the heterogeneous conditions. The catalytic system features base-free conditions, broad substrate scope, high chemoselectivity, operational simplicity, catalyst recyclability and utilization of O-2 as the green oxidant.