Synthesis of Green/Blue Light Emitting Quinolines by Aza-D-A Reaction Using InCl3 Catalyst

Abstract

An efficient InCl 3-catalyzed sequential reaction of aromatic amines, aromatic aldehydes and functionalized alkynes leading to the formation of new quinoline derivatives exhibiting significant fluorescence activities is described. The photophysical investigations of quinolines were carried out by absorption and photoluminescence measurements. One particular compound 4 h having maximum intensity, emitting green colour (Φ = 0.78) with average life time of 6.20 ns was the best amongst the tested compounds. The presence of the amino group at the 4-aryl substituent of the quinoline backbone played an important role in executing the Povarov cyclization successfully and enhancing the flourescence properties of the newly synthesized quinolines.

Arylselenyl Radical-Mediated Cyclization of N-(2-Alkynyl)anilines: Access to 3-Selenylquinolines

“…Intermediate 18 then oxidizes under the reaction conditions to produce a cationic species ( 19 ), which quickly rearomatizes to first provide a seleno-substituted dihydroquinoline ( 20 ) prior to the formation of 3a . This proposed pathway is in full agreement with previous reports in the literature that dihydroquinolines spontaneously oxidize, in air, to quinolines. ,, …”

“…This proposed pathway is in full agreement with previous reports in the literature that dihydroquinolines spontaneously oxidize, in air, to quinolines. 28,44,45 ■ CONCLUSIONS In summary, we successfully developed a novel and highly efficient method for accessing 3-selenylquinolines from acyclic, N-(2-alkynyl)aniline substrates upon their exposure to diaryl diselenide, CuCl…”

The Povarov Reaction: A Versatile Method to Synthesize Tetrahydroquinolines, Quinolines and Julolidines

“…Regarding the reaction medium, various polar and nonpolar solvents have been explored, for example, acetonitrile, 2,4,6,[22][23][24][36][37][38] THF, 159,161 DMSO, 160,162,163,166,173 ethanol, 146,[181][182][183] DMF, 158 acetic acid, 157 dichloromethane, 97,138,145,148,150,179,180,184 TFE, 137,152 diethyl ether, 185 dichloroethane, 140,142,151,153,165,186 chloroform 174 and toluene. 147,171,177 Greener alternatives were also reported such as the absence of a solvent 84,149,174,176,178 or the use of a DES (Scheme 13). For instance, Peña-Solórzano et al employed a low melting mixture of urea/zinc chloride as a DES in a multicomponent Povarov rea...…”

Annulation of 2‐Alkynylanilines: The Versatile Chemical Compounds

“…They used 2‐ethynylaniline 11 to react with imine 63 obtained from anilines and aldehydes in the presence of InCl 3 , passing from [4+2] cycloaddition reaction (Scheme 21). [70] …”

“…[67] Dimerization of 2-ethynylanilines was also catalyzed by the gold [68] and indium [69] ). [70] 2-Aryl-4-aminoquinolines 68 were synthesized through Pd(II)-catalyzed multicomponent domino reaction of 65, aryl iodides, primary amines, and carbon monoxide. Mechanisti- cally, this reaction includes two catalytic cycles to form intermediate 66 which is attacked by amine to give enamine 67.…”