18010-05-4Relevant articles and documents
Synthesis and photophysical insights of new fused N-heterocyclic derivatives with isoquinoline skeleton
Airinei, Anton,Craciun, Anda M.,Danac, Ramona,Gherasim, Carmen,Isac, Dragos Lucian,Mangalagiu, Ionel I.,Nicolescu, Alina,Tigoianu, Radu
, (2020)
Six new fused isoquinoline based compounds (compounds 5a–c with pyrrolo[2,1-a] isoquinoline structure and compounds 6a–c with imidazo[2,1-a]isoquinoline skeleton) have been synthesized using the [3 + 2] cycloaddition of the several in situ generated cycloimmonium ylides to ethyl propiolate or ethyl cyanoformate. All the synthesized compounds have been investigated in solution by UV–VIS absorption, steady and time-resolved fluorescence methods. The effect of the substituents on the spectral characteristics has been demonstrated. These derivatives displayed an intense emission between 360 and 420 nm. The emission quantum yields (Φ = 0.54–0.64) of pyrroloisoquinoline derivatives in dimethylsulfoxide (DMSO) were significantly higher than those of imidazoquinolines (0.03–0.16). The fluorescence decay of isoquinoline derivatives follows a biexponential law. A noticeable response of these isoquinoline derivatives to sodium hydroxide was observed.
Unprecedented access to functionalized pyrrolo[2,1-a]isoquinolines from the domino reaction of isoquinolinium ylides and electrophilic benzannulated heterocycles
Babu, Sheba Ann,A. R., Rajalekshmi,P. R., Nitha,Omanakuttan, Vishnu K.,P., Rahul,Varughese, Sunil,John, Jubi
, p. 1807 - 1817 (2021)
We have come across an unexpected reaction between electrophilic indoles and isoquinolinium methylides for accessing functionalized pyrrolo[2,1-a]isoquinolines. The reaction was found in general to yield the products in good yields. We also observed the f
Unified Synthesis of Azepines by Visible-Light-Mediated Dearomative Ring Expansion of Aromatic N-Ylides
Mailloux, Matthew J.,Fleming, Gabrielle S.,Kumta, Shruti S.,Beeler, Aaron B.
supporting information, p. 525 - 529 (2021/01/26)
Herein, we report a unified approach to azepines by dearomative photochemical rearrangement of aromatic N-ylides. Deprotonation of quaternary aromatic salts with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) or N,N,N′,N'-tetramethylquanidine (TMG) under visible light irradiation provides mono- and polycyclic azepines in yields up to 98%. This ring-expansion presents a new mode of access to functionalized azepines from N-heteroarenes using two straightforward steps and simple starting materials.
-Annulation of gem-Difluoroalkenes and Pyridinium Ylides: Access to Functionalized 2-Fluoroindolizines
Zhang, Jun-Qi,Hu, Dandan,Song, Jinyu,Ren, Hongjun
, p. 4646 - 4660 (2021/04/06)
A [3 + 2]-annulation of gem-difluoroalkenes and pyridinium ylides was developed employing ambient air as the sole oxidant in an open-vessel manner, affording a series of multifunctionalized 2-fluoroindolizines in moderate to good yields. In this reaction, gem-difluoroalkene acts as a C2 synthon and entirely avoids the competitive addition-elimination process, which provides facile access to 2-fluoroindolizines.
Diversified Transformations of Tetrahydroindolizines to Construct Chiral 3-Arylindolizines and Dicarbofunctionalized 1,5-Diketones
Feng, Xiaoming,He, Qianwen,Liu, Xiaohua,Pan, Chenjing,Su, Zhishan,Wu, Zhikun,Zhang, Dong,Zhou, Yuqiao
supporting information, p. 15975 - 15985 (2020/10/18)
Enantioselective diverse synthesis of a small-molecule collection with structural and functional similarities or differences in an efficient manner is an appealing but formidable challenge. Asymmetric preparation and branching transformations of tetrahydroindolizines in succession present a useful approach to the construction of N-heterocycle-containing scaffolds with functional group, and stereochemical diversity. Herein, we report a breakthrough toward this end via an initial diastereo- A nd enantioselective [3 + 2] cycloaddition between pyridinium ylides and enones, following diversified sequential transformations. Chiral N,N′-dioxide-earth metal complexes enable the generation of optically active tetrahydroindolizines in situ, across the strong background reaction for racemate-formation. In connection with deliberate sequential transformations, involving convenient rearomatic oxidation, and light-active aza-Norrish II rearrangement, the tetrahydroindolizine intermediates were converted into the final library including 3-arylindolizine derivatives and dicarbofunctionalized 1,5-dicarbonyl compounds. More importantly, the stereochemistry of four-stereogenic centered tetrahydroindolizine intermediates could be efficiently transferred into axial chirality in 3-arylindolizines and vicinal pyridyl and aryl substituted 1,5-diketones. In addition, densely functionalized cyclopropanes and bridged cyclic compounds were also discovered depending on the nature of the pyridinium ylides. Mechanism studies were involved to explain the stereochemistry during the reaction processes.
External oxidant-free oxidation/[3+2] cycloaddition/aromatization cascade: Electrochemical synthesis of polycyclic N-heterocycles
Wang, Qiang,Yuan, Ting,Liu, Qiang,Xu, Yong,Xie, Guanqun,Lv, Xin,Ding, Shujiang,Wang, Xiaoxia,Li, Chen
supporting information, p. 8398 - 8401 (2019/07/22)
Here, we describe an efficient and environmentally friendly synthesis of polycyclic N-heterocycles under electrochemical external oxidant-free conditions. The extent of the sequential electrochemical oxidative aromatization can be regulated with the assistance of redox mediators.
Pyrrolo[2,1-a]isoquinoline derivatives via 1,3-dipolar cycloaddition of isoquinolinium N-ylides (II)
Georgescu, Emilian,Dumitrescu, Denisa,Georgescu, Florentina,Draghici, Constantin,Dumitrascu, Florea
scheme or table, p. 691 - 695 (2012/04/04)
The reaction of N-isoquinolinium bromides 3 with acrylonitrile and crotononitrile as activated olefinic dipolarophiles gave in the presence of triethylamine and the oxidant tertrakis-pyridinecobalt(II) dichromate (TPCD), in DMF at 90 °C, 1-cyanopyrrolo[2,
1,2-Dihydroisoquinoline-N-Acetic Acid Derivatives as New Carriers for Specific Brain Delivery I: Synthesis and Estimation of Oxidation Kinetics Using Multivariate Calibration Method
Mahmoud, Sahar,Aboul-Fadl, Tarek,Sheha, Mahmoud,Farag, Hassan,Mouhamed, Abdel-Maaboud I.
, p. 573 - 584 (2007/10/03)
In order to overcome the slow oxidation of 1,2-dihydro-N-alkylisoquinoline, 1,2-dihydroisoquinoline-N-acetic acid derivatives (3 b-d) were designed and synthesized as new chemical delivery systems (CDS) for the brain. Molecular orbital calculations for th
Study of the reactivity of substituted phthalic acids and anhydrides in condensation reactions with N-carboxymethylpyridinium salts and the synthesis of novel N-(1H-indene-1,3(2H)-dion-2-yl)pyridinium betaines
Neilands,Shebenina,Pukitis
, p. 1443 - 1450 (2007/10/03)
Reaction of substituted phthalic acids or their anhydrides (including pyromellitic dianhydride) with salts of N-carboxymethylpyridinium and substituted N-carboxymethylpyridinium in the presence of acetic anhydride and triethylamine in acetonitrile or acetic acid solutions gave a series of novel N-(1H-indene-1,3(2H)-dion-2-yl)pyridinium betaines. Electron acceptor substitutents in the phthaloyl and pyridine rings were found to increase and electron donor substituents - to decrease the reactivity. 1999 Kluwer Academic/Plenum Publishers.
2-Methylpyridinium Salts as 1,4-Dinucleophiles. II. Westphal Condensation with Substituted Pyridinium Substrates
Ezquerra, J.,Alvarez-Builla, J.
, p. 1151 - 1157 (2007/10/02)
Condensation of α-methylpyridinium, quinolinium and isoquinolinium salts with 1,2-dicarbonyls in the presence of base, yielded quinolizinium derivatives.In an analogous process, α-benzyl derivatives produced 2,3-dihydroindolizin-2-ones by intramolecular c
