Regioselective Synthesis of Functionally Crowded Benzenes at Room Temperature through Ring Transformation of 2<i>H</i>-Pyran-2-ones
作者:Atul Goel、Fateh Singh、Vijay Kumar
DOI:10.1055/s-2007-984885
日期:——
An expeditious synthesis of highly substituted benzenes with electron-withdrawing or electron-donating substituents is described and illustrated by carbanion-induced ring transformation of 2H-pyran-2-one with malononitrile in excellent yield. The novelty of the reaction lies in the creation of an aromatic ring at room temperature from a six-membered lactone under mild reaction conditions.
Regioselective synthesis of 2-amino-isophthalonitriles through a ring transformation strategy
作者:Fateh V. Singh、Vijay Kumar、Brijesh Kumar、Atul Goel
DOI:10.1016/j.tet.2007.08.056
日期:2007.11
An expeditioussynthesis of several 2-amino-isophthalonitriles and their biaryl compounds is described and illustrated by carbanion-induced ring transformation of functionalized 2H-pyran-2-ones with malononitrile in excellent yields. The strength of the reaction lies in the creation of an aromatic ring at room temperature from six-membered lactones under mild reaction conditions. This approach is an
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.
New Fluoranthene FLUN-550 as a Fluorescent Probe for Selective Staining and Quantification of Intracellular Lipid Droplets
作者:Atul Goel、Ashutosh Sharma、Manoj Kathuria、Arindam Bhattacharjee、Ashwni Verma、Prabhat R. Mishra、Aamir Nazir、Kalyan Mitra
DOI:10.1021/ol403470d
日期:2014.2.7
A new class of live cell permeant, nontoxic fluoranthene-based fluorescent probe (FLUN-550) having a high Stokes shift in aqueous medium has been discovered. It showed selective staining of lipid droplets (LDs, dynamic cytoplasmic organelles) at a low concentration without background noise in in vitro live cell imaging of 3T3-L1 preadipocytes, J774 macrophages, MCF7 breast cancer cells, and single-celled, parasitic protozoa Leishmania donovani promastigotes and in vivo nonparasitic soil nematode C. elegans.