Diels-Alder Reaction of 1,2,3-Benzotriazine with Enamine: Application to the Synthesis of Alkaloids, 2-Propylquinoline and 2-Pentylquinoline.

Synthesis of aromatic heterocycles

“…242 A cycloaddition process that is mainly of mechanistic interest is the Diels-Alder reaction of 1,2,3-benzotriazine with enamines, from which 2-and 3-substituted quinolines were isolated in low yields. 243 …”

Six‐Membered Heterocycles: Quinoline and Isoquinoline

“…Hetero-Diels-Alder reaction of 1,2,3-benzotriazine in the presence of dienophiles produces quinoline derivatives after extrusion of N 2 . 1,2,3-Benzotriazine intermediate 80 can be obtained by oxidative rearrangement of 1-aminobenzotriazole (Scheme 17.52) [130].…”

Quinoline, quinazoline and acridone alkaloids

“…The Diels-Alder reaction of the pyrrolidine enamines of pentan-2-one or heptan-2-one with 1,2,3-benzotriazine 16 (formed in situ by oxidation of 1-amino-1H-indazole with lead tetraacetate) gave the simple alkaloids 2-propylquinoline 17 and 2-pentylquinoline 18 respectively in low yield. 36 2-Phenylquinoline 19 has been prepared in 90% yield by nickel(0)-catalysed cross-coupling of 2-chloroquinoline with phenylboronic acid. 37 Both 19 and the related compound dubamine 20 were produced in one-pot syntheses involving palladium-catalysed coupling of 2-iodoaniline with 1-arylpropargyl alcohols followed by palladium-induced cyclisation of the o-aminophenyl-substituted alkynol intermediates 21.…”