Solvent-free copper-catalyzed click chemistry for the synthesis of N-heterocyclic hybrids based on quinoline and 1,2,3-triazole

Abstract

Copper-catalyzed mechanochemical click reactions using Cu(II), Cu(I) and Cu(0) catalysts have been successfully implemented to provide novel 6-phenyl-2-(trifluoromethyl)quinolines with a phenyl-1,2,3-triazole moiety at O-4 of the quinoline core. Milling procedures proved to be significantly more efficient than the corresponding solution reactions, with up to a 15-fold gain in yield. Efficiency of both solution and milling procedures depended on the p-substituent in the azide reactant, resulting in H < Cl < Br < I reactivity bias. Solid-state catalysis using Cu(II) and Cu(I) catalysts entailed the direct involvement of the copper species in the reaction and generation of highly luminescent compounds which hindered in situ monitoring by Raman spectroscopy. However, in situ monitoring of the milling processes was enabled by using Cu(0) catalysts in the form of brass milling media which offered a direct insight into the reaction pathway of mechanochemical CuAAC reactions, indicating that the catalysis is most likely conducted on the surface of milling balls. Electron spin resonance spectroscopy was used to determine the oxidation and spin states of the respective copper catalysts in bulk products obtained by milling procedures.

Quinoline and ferrocene conjugates: Synthesis, computational study and biological evaluations

“…Compounds 2‐(trifluoromethyl)quinolin‐4(1 H )‐one ( 3a ), 6‐methyl‐2‐(trifluoromethyl)‐quinolin‐4(1 H )‐one ( 3b ), 6‐phenyl‐2‐(trifluoromethyl)quinolin‐4(1 H )‐one ( 3d ), 1‐methylazidoferrocene and 1‐azidoethylferrocene were synthesized according to known procedure.…”

Novel Bis- and Mono-Pyrrolo[2,3-d]pyrimidine and Purine Derivatives: Synthesis, Computational Analysis and Antiproliferative Evaluation

“…Based on the known protocols [51] for CuAAC reaction that include the in situ generation of Cu(I) from a Cu(II) salt or the alternative direct utilization of a Cu(I) source using the combination of CuI/DIPEA/HOAc, which has been found to be a highly efficient catalytic system for this reaction [52], we performed an optimization of the CuAAC reaction using methods A-C.…”

Triazoles with long chain alkyl groups as a potential biological compounds

“…Compound [3] (1 equiv) was stirred contentiously with (1.1 equiv) of corresponding propargyl alcohol [5-8] and (0.01equiv) copper chloride and sodium ascorbate (0.1 equiv) in methanol when TLC indicates there are no traces of the azide. The reaction mixture iltrate through ciliate and the solvent removed under reducing pressure, the residue was puri ied through column chromatography using 9:1 chloroform: methanol as eluent to produce the target derivatives (Yáñez-Sedeño et al, 2019;Tireli et al, 2017;Ostrovskis et al, 2013) .…”