Copper-catalyzed synthesis of quinoline derivatives via tandem Knoevenagel condensation, amination and cyclization

Abstract

A novel regioselective synthesis of 2-aminoquinolines and 2-arylquinoline-3-carbonitriles is described via copper-mediated tandem reaction.

Design, synthesis and crystallographic study of novel indole-based cyano derivatives as key building blocks for heteropolycyclic compounds of major complexity

“…The supramolecular assembly of compound (V) was not mentioned in the original report (Dhiman et al, 2016) and we therefore discuss it here. Four hydrogen bonds are present (Table 3) and these together link the molecules into very complex sheets, whose formation can, however, be readily analysed in terms of two simpler one-dimensional substructures (Ferguson et al, 1998a,b;Gregson et al, 2000).…”

“…As noted above, the structure of compound (V) has recently been reported at ambient temperature and refined in the space group P1 with Z 0 = 2 (Dhiman et al, 2016). Comparison of the atomic coordinates for corresponding pairs of atoms in this structure showed that the two molecules in the selected asymmetric unit are very precisely related by a noncrystallographic 2 1 screw axis along (x, 3 4 , 3 4 ), and a detailed examination of this structure for additional symmetry elements (PLATON; Spek, 2009) found a 100% fit to space group P2 1 /n with Z 0 = 1, in a unit cell with dimensions a = 10.896 Å , b = 8.952 Å , c = 13.292 Å and = 96.15 , very similar to the monoclinic unit cell found here at 100 K. Although a request to the authors of the original report for a copy of their .hkl file proved fruitless, we are nonetheless reasonably confident that compound (V) does not, in fact, exhibit temperature-dependent polymorphism, but that the ambient-temperature structure was refined in the wrong space group.…”

“…We also report here a redetermination of the structure of the chalcone 2-benzoyl-3-(2-bromophenyl)acrylonitrile, (V), which is related to chalcone (I), but with a simple phenyl group in place of the substituted indolyl unit. The structure of this chalcone has been reported recently at ambient temperature, in the space group P1, with Z 0 = 2 (Dhiman et al, 2016), but the structure was refined only to R1 = 0.157 and wR2 = 0.341, with S = 1.410. As we had occasion to prepare this compound at an early stage in the present study, we have taken the opportunity to collect a new data set at 100 K, where the compound is monoclinic, space group P2 1 /n with Z 0 = 1, suggesting the possibility of temperature-dependent polymorphism.…”

The synthesis ofN‐containing heterocyclic compounds catalyzed by copper/L‐proline

“…In 2016, Kumar's group developed a method to prepare 2‐aminoquinolines 86 through CuI‐catalyzed tandem reaction of bromobenzaldehydes 84 , cyanoacetates 85 , and NaN 3 (Scheme 16). [ 50 ] This strategy showed wide substrate scope, excellent tolerance toward functional group, and used readily available compounds as the starting materials, but high reaction temperature was needed. The yields of 86a with and without the ligand were respectively obtained in 62% and 20%, which suggested that the ligand advanced the conversion of 87 to 88 , and 88 to 89 .…”

Copper-Catalyzed Tandem Imine Formation, Sonogashira Coupling and Intramolecular Hydroamination: A Facile Synthesis of 3-Aryl-γ−carbolines

“…In continuation of our ongoing efforts towards developing newer methodologies for the synthesis of N ‐fused heterocycles,,, herein, we wish to report an efficient and operationally simple synthetic method for the construction of 3‐aryl‐γ‐carbolines via Cu‐catalyzed one‐pot, multicomponent reaction of 2‐bromo‐1‐methyl‐1 H ‐indole‐3‐carbaldehydes with terminal alkynes and aqueous ammonia.…”