Polystyrene supported N-phenylpiperazine–Cu(ii) complex: an efficient and reusable catalyst for KA²-coupling reactions under solvent-free conditions

Abstract

Propargylamines were synthesized in excellent yields from cyclohexanone and pentanone with a variety of secondary amines and alkynes by employing a new polystyrene supported N-phenylpiperazine–Cu(ii) complex 4c.

Manganese‐Catalyzed Multicomponent Synthesis of Tetrasubstituted Propargylamines: System Development and Theoretical Study

“…[68] Naturally, the increasing interest in this reaction and its potential has led to the development of a multitude of heterogeneous catalytic systems. Some leading examples include the use of Cu 2 O nanoparticles on titania, [69] nano Cu 2 O-ZnO, [70] Cu 2 O/nano-CuFe 2 O 4 , [71] CuO/Fe 2 O 3 nanoparticles, [72] Cu(II)-hydromagnesite, [73] polystyrene-supported, N-phenylpiperazine-CuBr 2 , and highly active, polymer-supported bipyridine-CuBr 2 , [74] Cu(II) @furfural imine-decorated Halloysite, [75] CuI on Amberlyst A-21, [76] as well as semi-heterogeneous, magnetically recoverable graphene oxide-supported CuCl 2. [77] Catalytic systems based on other metals have been also developed, such as Ag-doped nanomagnetic γ-Fe 2 O 3 @DA core-shell hollow spheres, [78] Fe 2 O 3 @SiO 2 -IL/Ag hollow spheres, [79] and polystyrene-supported N-heterocyclic carbene-Au(III).…”

KA2‐Coupling Reaction Catalyzed by Semi‐Heterogeneous Magnetically Graphene Oxide Supported Copper Catalyst under Microwave Condition

“…Compared with other similar heterogeneous catalysts (such as Amberlyst A‐15 supported copper (II) catalyst, 10 hours, 98 o C, 44% yield, Cu(OH) x ‐Fe 3 O 4 , 7 days, 120 o C, 29–38% yields), the new style catalyst GO‐Fe 3 O 4 ‐CuCl 2 possessed higher catalytic activity (40 min, 70–93%) under MW irradiation. Although under traditional heating condition, the KA 2 coupling reaction also could proceed smoothly to give the desired product in 94% yield within 8 h at 90 o C. The semi‐heterogeneous property and excellent accessibility of the magnetic catalyst GO‐Fe 3 O 4 ‐CuCl 2 might cause high catalytic activity.…”

“…Up to now, only several heterogeneous catalysts have been prepared and used to synthesize propargylamines via one‐pot three‐component KA 2 coupling reaction. The solid immobile materials included polystyrene, Amberlyst A‐21, Cu(OH) x ‐Fe 3 O 4 , and hydromagnesite…”

Eco‐friendly magnetic clinoptilolite containing Cu(0) nanoparticles (CuNPs/MZN): as a new efficient catalyst for the synthesis of propargylamines via A3 and KA2 coupling reactions

“…Propargylamines have been utilized in the synthesis of various nitrogen‐heterocycles such as pyrrolidines, pyrroles, oxazoles as natural bioactive and pharmaceutical compounds . Among the various methods for the preparation of propargylamines in the presence of homogeneous or heterogeneous catalysts, one pot, three component reaction of aldehydes/ketones, secondary amines and terminal alkynes (A 3 /KA 2 coupling) are more common without the need for any external oxidant …”

“…A literature survey disclosed that, Cu (OH)x–Fe 3 O 4 was the first heterogeneous catalyst employed for the synthesis of propargylamines via KA 2 coupling . Recently, Ti (OEt) 4 was employed as Lewis acid for neat KA 2 coupling reaction of acyclic and cyclic aliphatic ketones under solvent free and green conditions to enhance the activity of the substrates, yields, and lowering the reaction times .…”