FeCl₃-Promoted ring size-dictating diversity-oriented synthesis (DOS) of N-heterocycles using in situ-generated cyclic imines and enamines

Abstract

The FeCl3-promoted ring size-controlled oxidative activation of o-alkynylanilines opens up a complementary appealing protocol for poly-N-heterocycle synthesis.

Annulation of 2‐Alkynylanilines: The Versatile Chemical Compounds

“…5-Me as R 2 , and H as R 1 and R 3 showed the best results in terms of reaction time and the product yield. [49] Synthesis of 2,2'-diphenyl-2,3'-biindolin-3-ones 21 was accomplished via parallel indole and indoline-3-one 20 synthesis in the presence of gold/copper-co-catalyst. The t-butyl hydroperoxide acts as an oxygen source to promote the formation of intermediate 19, which is oxidized to 20 in the presence of Cu(II).…”

“…In this reaction, different substitutions were subjected in both 2‐alkynylaniline ring and indenone's phenylene ring. 5‐Me as R 2 , and H as R 1 and R 3 showed the best results in terms of reaction time and the product yield [49] …”

“…In another research, 2‐alkynylanilines 8 were treated with cyclohexanone 94 under oxidative condition by the use of FeCl 3 in DMSO to promote formation of bis‐imine 95 , then 6‐ exo‐dig cyclization furnishing the corresponding dibenzo[ b , j ][1,10]phenanthroline compounds 96 (Scheme 30). The obtained acridines were completely unsaturated due to under aza‐allyl oxidation condition [49] . These structure are valuable due to their electronic properties to be used in different fields of science like chemosensors, dyes, and OLEDs [82] .…”

“…[81] In another research, 2-alkynylanilines 8 were treated with cyclohexanone 94 under oxidative condition by the use of The obtained acridines were completely unsaturated due to under aza-allyl oxidation condition. [49] These structure are valuable due to their electronic properties to be used in different fields of science like chemosensors, dyes, and OLEDs. [82] Marsicano et al employed Brønsted acid to catalyze this reaction and could achieve 2,2,3-substituted-2,3-dihydroquinolin-4(1H)-ones 97 via the proposed mechanism shown in Scheme 31.…”

Acid-Promoted Intramolecular Decarbonylative Coupling Reactions of Unstrained Ketones: A Modular Approach to Synthesis of Acridines and Diaryl Ketones

“…The role of the solvent in these C–C bond activation reactions is crucial, because a high yield was only obtained when polar aprotic solvents were employed (Supporting Information Table S1). Moreover, the DMSO played a dual role as both an oxidant and a solvent . The low-temperature reaction failed to furnish the decarbonylated product (entry 12).…”