1,2,3-Triazines and their Benzo Derivatives

Carbon‐metalated triazines and tetrazines: Synthesis and reactivity

“…[14] Unsubstituted 1,2,3-triazine, as well as 4-and 5-phenyl-1,2,3-triazines 13 and 20 afforded very complex mixtures of products upon reaction with LiTMP or a mixture LiTMP/TMSCl or ArCHO already at low temperatures (Schemes 3 and 4). [11] Mainly, functionalized acyclic derivatives, such as alkenes 16 to 19, 23, 24 were isolated. Such reactions may involve the ring opening of the metalated six-membered aromatic rings 21 or 14 with subsequent extrusion of nitrogen molecules.…”

“…[9] Several brief notes regarding this class of organometallic heterocyclic derivatives were presented occasionally since then in general reviews and monographs. [10][11][12] Due to the variety of transformations that carbon-metalated triazines and tetrazines can undergo, the apparent synthetic potential and their potent practical significance, it seems clear now that there is a need for the first comprehensive organization of the published data. The growing number of original literature sources considering the N-metalated derivatives (including transition metal complexes [13] ) is also a positive underlying trend, however, these will not be discussed herein.…”

Copper-Catalyzed Domino Annulation Approaches to the Synthesis of Benzoxazoles under Microwave-Accelerated and Conventional Thermal Conditions

“…Classical methods for the synthesis of benzoxazoles 4 involve the formation of the O1−C2 and N3−C2 bonds, via the condensation of a 2-aminophenol 5 with either a carboxylic acid derivative under strong acid/high temperature conditions or an aldehyde, followed by oxidation (Figure a and b) . Such reactions have also been applied in automated sequential synthesis, such as Player’s report of the microwave-accelerated coupling of 2-aminophenols with acyl chlorides (210 °C for 15 min) .…”