A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles
摘要:
An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions. (C) 2014 Elsevier Ltd. All rights reserved.
simple, efficient and transition metal-free strategy was established for the synthesis of highly functionalized, stericallyhindered allylarenes (6, 7 & 8) by base-mediated ring transformation of 2-oxo-6-aryl-4-(methylthio/sec-amino)-2H-pyran-3-carbonitriles (3/4) with 5-hexene-2-one (5). This provides a method for the synthesis of allylarenes functionalized with different electron donating and withdrawing
A simple, efficient and economical synthesis of dimethyl 3-amino-5-(2-oxo-2-arylethyl)thiophene-2,4-dicarboxylates has been reported by ring opening of methyl 3-amino-6-aryl-4-oxo-4H-thieno[3,2-c]pyran-2-carboxylates by alkoxide ions.
An expeditious synthesis of imidazo[1,2-a]pyridines through nucleophile induced ring transformation reactions of 6-aryl-4-methylsulfanyl-2H-pyran-2-one-3-carbonitriles
作者:Vishnu Ji Ram、Nidhi Agarwal、Ashoke Sharon、Prakas R Maulik
DOI:10.1016/s0040-4039(01)02112-8
日期:2002.1
An efficient and convenient synthesis of 2-(5-aryl-8-nitro-2,3-dihydroimidazo[1,2-a]pyridin-7(1H)-ylidene)acetonitriles (3) and 6-aryl-4-2-[(E)-nitromethylidene]-1-imidazolidinyl}-2-oxo-2H-pyran-3-carbonitriles (4) through nucleophile induced ring transformation of suitably functionalized 2H-pyran-2-one (1) from imidazoliden-2-ylidene nitromethane is delineated.
有效和方便地合成2-(5-芳基-8-硝基-2,3-二氢咪唑并[1,2 - a ]吡啶-7(1 H)-亚烷基)乙腈(3)和6-芳基-4- 2-[(E)-硝基亚甲基] -1-咪唑啉基} -2-氧代-2 H-吡喃-3-甲腈(4)通过亲核试剂诱导的适当官能化的2 H-吡喃-2-酮的环转化(1)描绘了由咪唑啉-2-亚甲基硝基甲烷衍生的产物。
A facile access to the synthesis of functionalised unsymmetrical biaryls from 2H-pyran-2-ones through carbanion induced C–C bond formation †
作者:Vishnu J. Ram、Mahendra Nath、Pratibha Srivastava、Sanjay Sarkhel、Prakas R. Maulik
DOI:10.1039/b005572g
日期:——
A convenient synthesis of highly functionalised biaryls 3 and 6 has been delineated throughcarbanion induced C–C bond formation from 6-aryl-3-cyano-4-substituted-2H-pyran-2-ones (1, 4) and acetone. Extension of this reaction, using aromatic ketones led to (4,6-diarylpyran-2-ylidene)acetonitrile (7) in lieu of the anticipated 2,4-diaryl-6-methylthiobenzonitrile (8). The structure of 2-methyl-6-methylthio-4-(3
Synthesis of Solution-Processable Donor–Acceptor Pyranone Dyads for White Organic Light-Emitting Devices
作者:Chandra P. Sharma、Neeraj M. Gupta、Jagriti Singh、Rohit Ashok Kumar Yadav、Deepak Kumar Dubey、Kundan S. Rawat、Ajay K. Jha、Jwo-Huei Jou、Atul Goel
DOI:10.1021/acs.joc.9b00293
日期:2019.6.21
A series of donor-acceptor pyranones (3a-m, 4a-h) were synthesized using alpha-oxo-ketene-S,S-acetal as the synthon for their application as emissive materials for energy-saving organic light-emitting devices (OLEDs). Among them, five pyranones 3f, 3g, 3h, 3m, and 4e exhibited highly bright fluorescence in the solid state and weak or no emission in the solution state. Photophysical analysis of these dyes revealed that only 3f and 3m showed aggregation-induced emission behavior in a THF/water mixture (0-99%) with varying water fractions (f(w)) leading to bright fluorescence covering the entire visible region, while other derivatives 3g, 3h, and 4e did not show any fluorescence signal. The computational studies of the compounds revealed that the longer wavelength absorption originates from HOMO to LUMO electronic excitation. These dyes exhibited good thermal stability with 5% weight loss temperature in the range of 218-347 degrees C. The potential application of the donor-acceptor pyranone dyads was demonstrated by fabrication of solution-processed OLEDs. Remarkably, OLED devices prepared using highly emissive compounds 6-(anthracen-9-yl)-4-(methylthio)-2-oxo-2H-pyran-3-carbonitrile (3m) and 6-(4-methoxyphenyl)-4-(methylthio)-2-oxo-2H-pyran-3-carbonitrile (3f) displayed pure white emission with CIE coordinates of (0.29, 0.31) and (0.32, 0.32), respectively. Additionally, the resultant devices exhibited external quantum efficiencies of 1.9 and 1.2% at 100 cd m(-2), respectively.