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

Abstract

Herein, we reported Lewis acid- or Brønsted acid-promoted intramolecular C­(sp2)-C­(sp2) bond cleavage and a novel C­(sp2)-C­(sp2) bond-forming cascade reaction to synthesize the acridine motif. The metal-free oxidation of the alkyne motif generated the in situ ketone group extracted via a decarbonylation reaction. The mechanistic studies revealed that the electrophilic N-iodo species triggered key decarbonylation reactions via consecutive dearomatization/aromatization reactions. In addition, we exploited this acid-promoted C–C bond activation system with internal alkynes to synthesize bis­(heteroaryl) ketones.

Fe3O4@Sap/Cu(ii): an efficient magnetically recoverable green nanocatalyst for the preparation of acridine and quinazoline derivatives in aqueous media at room temperature

“…30 Therefore, due to the broad application of acridine and quinazoline derivatives, their synthesis is very important in synthetic organic chemistry. 31 In the last few decades, a variety of synthetic methodologies have been expanded for the preparation of acridine and quinazoline derivatives. 32 In this regard, it can be a point to the reactions such as domino synthetic protocols, 33 aza-Diels-Alder reactions, 34 oxidative cyclization, 35 cyclo condensation reactions, and Bernthsen synthesis.…”

2‐(Alkynyl)anilines and Derivatives — Versatile Reagents for Heterocyclic Synthesis

“…An impressive decarbonylative domino sequence, furnishing dihydrobenzo[c]acridines 101 was recently developed by Wang and co‐workers [117] . This oxidative transformation was promoted by BF 3• OEt 2 or TfOH and carried out in the presence of PIDA and oxygen.…”

Annulation of 2‐Alkynylanilines: The Versatile Chemical Compounds

“…Decarbonylative process is accelerated by phenyliodine(III) diacetate (PIDA) and gives the target structure 102 through a rearrangement passing from 101 (Scheme 32). The use of 2,3‐dihydro‐1 H ‐inden‐1‐one ( 98 , n=0) gave no desire product [84] . Sivaraman and Perumal employed 1,3‐diketones to react with 2‐ethynylanilines, achieving 4‐methyl‐2,3‐disubstituted quinolines [85] …”

“…The use of 2,3-dihydro-1Hinden-1-one (98, n = 0) gave no desire product. [84] Sivaraman and Perumal employed 1,3-diketones to react with 2-ethynylanilines, achieving 4-methyl-2,3-disubstituted quinolines. [85] Not only ketones, but also aldehydes can be treated with 2-alkynylanilines.…”