Solvent-controlled divergent annulation of ynones and (iso)quinoline N-oxides: of 3-((iso)quinolin-1-yl)-4H-chromen-4-ones and 13H-isoquinolino[2,1-a]quinolin-13-ones

Abstract

An effective annulation of ynones and (iso)quinoline N-oxides was developed to divergently prepare 3-((iso)quinolin-1-yl)-4H-chromen-4-ones and 13H-isoquinolino[2,1-a]quinolin-13-ones under transition-metal-free conditions.

Oxone-Promoted Synthesis of 4-(Chalcogenyl)isoquinoline-N-oxides from Alkynylbenzaldoximes and Diorganyl Dichalcogenides

“…Isoquinoline N -oxides and their derivatives represent an important structural unit found in several alkaloids and in compounds with relevant pharmacological activities, e.g., antiviral (HIV), antifungal, and anticancer activities . These compounds are usefully applied in organic synthesis as chiral organocatalysts and as precursors in olefination, cycloaddition, and alkynylation reactions . In addition, N -oxides have a large space in materials science and can be used as efficient dual channel fluorosensors for Li + , Mg 2+ , and Ca 2+ cations …”

Cascade Reaction of o‐Haloaryl Ynone and 2‐Hydroxy‐2‐Methylchromene: Synthesis of Chromone Derivative Enabled by Oxygen‐Migration

“…[9] In addition, the reactions of o-haloaryl ynones with other starting materials such as allylic alcohols and (iso)quinoline N-oxides have also been investigated. [10] It was also worthy to note that the comparison between o-haloaryl ynone and its analog without halogen was also demonstrated in some of the above-mentioned examples. On the other hand, 3-acyl-2-hydroxy-2-methylchromene as precursor for the preparation of chromene derivative has been utilized to participate in a variety of transformations.…”

“…Of the solvents tested, toluene and DCE brought negative results, whereas DMF, DMA and DMSO significantly enhanced the yield of product 3 a (Table 1, entries 2-6). We were sadly to find that the replacement of Cs 2 CO 3 with other organic and inorganic bases could not help to improve the reaction (Table 1, entries [7][8][9][10][11]. The experimental results demonstrated that the present reaction was very sensitive to reaction temperature.…”

Catalyst- and Additive-Free Annulation of Ynediones and (Iso)Quinoline N-Oxides: An Approach to Synthesis of Pyrrolo[2,1-a]Isoquinolines and Pyrrolo[1,2-a]Quinolines

“…Although the annulation of ynediones has been broadly explored, these reactions usually need catalyst or additive or high temperature. Recently, our group and other groups separately reported the reaction of alkynes and N -oxides to construct an array of functionalized derivatives under a transition-metal-free condition. Inspired by the mechanism for the reaction of ynones with (iso)­quinoline N -oxides, the cyclization reaction of ynediones, and our successful transitions of ynones, , we envisioned that pyrrolo­[2,1- a ]­isoquinolines and pyrrolo­[1,2- a ]­quinolines may be easily prepared from ynediones and (iso)­quinoline N -oxides through a tandem [3 + 2] cycloaddition/ring-opening/ N -nucleophilic addition reaction under catalyst- and additive-free condition (Scheme ).…”