Divergent Palladium- and Platinum-Catalyzed Intramolecular Hydroamination/Hydroarylation of O-Propargyl-2-aminophenols

A fruitful divergent cyclization of terminal alkynes arising from 2-aminophenols depending on the transition metal employed is reported. Under palladium- and platinum-catalysis, the total regioselective carbon–nitrogen or carbon–carbon bonds formation afforded 1,4-benzoxazines or benzopyrans, through different reaction pathways. The subsequent functionalization of the benzopyran scaffold paved the way for a new synthesis of the tricyclic pyrano[3,2-h]quinolines.