Divergent Sc(OTf)3‐Catalyzed Tandem Cyclization of o‐Hydroxyphenyl Enaminones with 1,3,5‐Triazinanes: Access to C3‐Aminomethyl Chromones and Tetrahydropyrimidines

Abstract A Sc(OTf) 3 ‐catalyzed tandem cyclization reaction of o ‐hydroxyphenyl enaminones with 1,3,5‐triazinanes has been developed to generate two distinct annulated products in moderate to good yields, which is dominated by the electronic characteristics of the 1,3,5‐triazinanes. The 1,3,5‐triaryl‐1,3,5‐triazinane reacted as C−N synthon to produce C3‐aminomethyl chromone, while the 1,3,5‐trialkyl‐1,3,5‐triazinane acted as C−N−C−N synthons to deliver N , N ‐dialkyl tetrahydropyrimidine with a free hydroxyl group.