Domino Aza-Michael-ih-Diels–Alder Reaction to Various 3-Vinyl-1,2,4-triazines: Access to Polysubstituted Tetrahydro-1,6-naphthyridines

Abstract

A straightforward domino aza-Michael-inverse-electron-demand-hetero-Diels-Alder/retro-Diels-Alder reaction between primary and secondary propargylamine derivatives and 3-vinyl-1,2,4-triazines is developed highlighting not only the uniqueness of this dual-heterocyclic platform but also a novel and unprecedented path to polysubstituted tetrahydro-1,6-naphthyridine scaffolds.

Gold(I)-Catalyzed Reactivity of Furan-ynes with N-Oxides: Synthesis of Substituted Dihydropyridinones and Pyranones

“…To provide a glimpse of the synthetic value of the products of our Au(I)-catalyzed methodology, we subjected 2a to the synthetic manipulations reported in Scheme 4 . Remarkably, the Michael addition of thiophenol, catalyzed by Et 3 N, 15 proceeded smoothly at room temperature with complete selectivity for the exocyclic double bond over the endocyclic one, thus obtaining sulfide 5 . Similarly to the Michael addition, also the hydrogenation over Pd/C was selective for the exocyclic double bond, affording the partially saturated compound 6 .…”

Synthesis of 3‐Keto Pyridines from the Conjugated Allenone – Alkynylamine Oxidative Cyclization Catalyzed by Supported Au Nanoparticles

“…Allenyl ester 18 is commercially available, while compounds 16 and 19 were prepared following a known procedure . Apart from the commercially available propargylamine and homopropargylamine, their aryl‐substituted counterparts were synthesized as described in the Supporting Information, using known literature procedures …”

“…[29] Apart from the commercially available propargylamine and homopropargylamine, their aryl-substituted counterparts were synthesized as described in the Supporting Information, using known literature procedures. [21,30] General procedure of the Au/TiO 2 -catalyzed cyclization: To a vial containing a solution of 0.2 mmol of allenone or allenyl ester in toluene (0.5 mL) are added 0.22 mmol of the alkynylamine. After stiring for 10 min at 25°C, Au/TiO 2 (74 mg, 2.0 mol% in Au) is added and the mixture is heated to 110°C for a certain period of time until the reaction was complete (see Tables 1 and 2).…”

The Riveting Chemistry of Poly‐aza‐heterocycles Employing Microwave Technique: A Decade Review

“…A domino aza‐Michael‐retro Diels‐Alder reaction of primary or secondary propargyl amines with triazine 59 ; accomplished the unprecedented path to functionalized tetrahydro‐1,6‐naphthyridine scaffolds 60 . The reaction started at ambient temperature in methanol (polar‐protic solvent) led to aza‐Micheal addition product 59 i without detection of domino product 60 for 24 h. Perhaps, the reaction in non‐polar solvents at room temperature was inappropriate, but heating at 180 °C under microwave irradiation for 3.5 h in THF exclusively afforded domino product 1,6‐naphthyridines ( 60 ) in good yields [32a] . In the reaction protocol, N ‐alkoxy propargyl amines were also efficiently used with trifluoromethanesulfonimide as an organocatalyst [32b] .…”