36 research outputs found
Copper-Catalyzed Simultaneous Activation of C–H and N–H Bonds: Three-Component One-Pot Cascade Synthesis of Multisubstituted Imidazoles
No full textA copper-catalyzed expedient, practical, and straightforward approach for the one-pot three-component modular synthesis of multisubstituted imidazoles has been described by using arylacetic acids, N-arylbenzamidines, and nitroalkanes. The reaction involves simultaneous activation of C–H and N–H bonds of arylacetic acids and N-arylbenzamidines, respectively. The use of inexpensive copper sulfate as a catalyst, readily available starting materials, and Celite-free workup makes this protocol economically viable. Multisubstituted imidazoles were obtained in moderate to good yields with significant functional group tolerance and high regioselectivity
An Efficient Synthesis of 1,2,4-Trisubstituted Imidazoles from Arylacetic Acids and N -Arylbenzamidines via Simultaneous C-H and N-H Bond Activation
No full textA convenient and effective FeCl3 catalyzed one-pot three
component protocol for the synthesis of 1,2,4-trisubstituted
imidazoles from arylacetic acids, N-arylbenzamidines and nitromethane
via simultaneous CH and NH bond activation has
been developed. The reaction involves CH activation of
arylacetic acid to form aromatic aldehyde which on condensation
with N-arylbenzamidine gives azadiene. Nitromethane on
Michael addition with azadiene produces ring annulated
intermediate which upon subsequent cyclization-elimination
sequence offers imidazole. The process utilizes readily available
arylacetic acids and inexpensive catalyst. This user friendly
protocol provided 1,2,4-trisubstituted imidazoles in moderate
to good yields with high functional group tolerance and ample
substrate scope
Tandem Protocol for the Synthesis of 3-Acyl Benzothiadiazine 1,1-Dioxides
No full textA metal-free and efficient tandem synthesis of 3-acyl 3,4-dihydro-2H-1,2,4-benzothiadiazine-1,1-dioxides and 3-acyl-2H-1,2,4-benzothiadiazine-1,1-dioxides has been developed via C−H functionalization of ethynylarenes and ethenylarenes followed by condensation with 2-aminobenzenesulfonamide. The reaction involves the formation of arylglyoxal as an intermediate from multiform substrates through Kornblum oxidation in the presence of iodine and DMSO. Use of simple and readily available starting materials, inexpensive reagent, broad substrate scope and a very simple operation are noteworthy features of this protocol. This method provides an easy access to pharmaceutically important 3-acyl-1,2,4-benzothiadiazine-1,1-dioxides in good yields
ChemInform Abstract: Direct Allylation of Alcohols Using Allyltrimethylsilane and a Move Towards an Economical and Ecological Protocol for C—C Bond Formation
No full textSynthesis and antibacterial activity of new oxadiazolo[1,3,5]-triazine, 1,2,4 triazolo and thiadiazolo 1,3,4 oxadiazole derivatives
No full text1710-17153-Formyl-4-hydroxycoumarin has been treated with semicarbazide to give 4-hydroxy-2-oxo-2H[1]-benzopyran-3-aldehyde semicarbazone 1a-d, which on oxidative cyclization with bromine in glacial acetic acid in the presence of anhydrous sodium acetate gives 3-(5-amino-1,3,4-oxadiazol-2-yl)-4-hydroxy-2H[1]-benzopyran-2-one 2a-d. 3-(5-amino-1,3,4-oxadiazol-2-yl)-4-hydroxy-2H[1]-benzopyran-2-one on reaction with benzaldehyde gives 4-hydroxy-3-(5-benzylidine imino 1,3,4-oxadiazol-2-yl)-2H[1]-benzopyran-2-one 3a-d. 3a-d on (4+2) cycloaddition with phenyl isothiocynate gives 3-(6,7-diphenyl-5-thioxo-6,7-dihydro-5H-[1,3,4]oxadiazolo[3,2-][1,3,5]triazin-2-yl)-4-hydroxy-2H[1]-benzopyran-2-one 4a-d. 2a-d undergoes regioselective condensation with KSCN in methanol to give N-[5-(4-hydroxy-2-oxo-2H[1]-benzopyran-3-yl)-1,3,4,-oxadiazol-2-yl]thiourea 5a-d whereas with phenyl isothiocynate it gives N-[5-(-4-hydroxy-2-oxo-2H[1]benzopyran-3-yl)-1,3,4-oxadiazole-2-yl]-N'-phenylthiourea 7a-d. 5a-d reacts with thionyl chloride in pyridine to give 4-hydroxy-3-(6-thioxo-5,6-dihydro[1,2,4]triazolo[5,1-b][1,3,4]oxadiazol-2-yl)-2H[1]-benzopyran-2-one 6a-d. 7a-d on treatment with ethanol and iodine yields 4-hydroxy-3-[6-phenylimino-6H-[1,2,4]-thiadiazolo[3,2-b][1,3,4]-oxadiazol-2-yl]-2H[1]benzopyran-2-one 8a-d
, and sp C—H Functionalization and Oxidative Cross Coupling with Benzamidines Hydrochloride: A Promising Approach for the Synthesis of α‐Ketoimides.
No full text
A novel twisted Donor-Acceptor structures with cyano substituents for advancements in Near-Infrared Red TADF Emitters
No full textThe designing and development of near-infrared (NIR) red emitters have attracted significant attention owing to the challenges of achieving the necessary energy levels for harvesting both singlet and triplet excitons and their unique requirements for this spectral range. Herein, we have reported the designing and synthesis of two novel red TADF emitters 4,4\u27-(3,6-bis(9,9-dimethylacridin-10(9H)-yl)dibenzo[a,c]phenazine-11,12-diyl)dibenzonitrile (Ac-PhCNDBPZ) and 4,4\u27-(3,6-di(10H-phenoxazin-10-yl)dibenzo[a,c]phenazine-11,12-diyl)dibenzonitrile (PXZ-PhCNDBPZ) having twisted donor-acceptor structures. A cyano substituent helps to increase the wavelength towards the redshift. These emitters show near-IR emissions at 602 and 698 nm. This work proves that the cyano substituent and rigid acceptor with a strong donor could be an effective approach to exploring high-efficiency red near-infrared TADF materials
Synergistic Insights into Pyrazinophenazine based Hybrid Materials for Advancing Optoelectronics
No full textWe have synthesized a two novel hybrid molecules 3-(4-(9,9-dimethylacridin-10(9H)-yl)phenyl)-12,13-diphenyldibenzo[a,c]pyrazino[2,3-i]phenazine (Ac-DibzPyrQx) and 3-(4-(3,6-di-tert-butyl-9H-carbazol-9-yl)phenyl)-12,13 diphenyldibenzo[a,c]pyrazino [2,3-i]phenazine (tCz-DibzPyrQx), comprising electron-donating (9,9-dimethyl-9,10-dihydroacridine, 3,6-di-tert-butyl-9H-carbazole) and electron accepting Pyrazinophenazine groups. The two different electron-donating groups with pyrazinophenazine were synthesized with the view to tune the photophysical and electrochemical properties of the hybrids. The photophysical study displayed absorption maxima in the range of 320-340 nm and 400-500 nm whereas emission maxima at 602 and 540 nm in toluene for these emitters respectively. These compounds showed high thermal and morphological stability, as well as appropriate frontier molecular orbital (FMO) energy levels. These synthesized molecules show very high decomposition temperatures (3000C and 3800C) and exhibited good glass transition temperatures (3280C and 3000C), indicating their significant stability and potential utility as a bipolar host material for efficient phosphorescent organic light-emitting diodes (PhOLEDs) and TADF molecules
