Three-component Coupling Reaction Of Alkynes Research Articles

Transition-metal-free three-component coupling approach to QUINAP derivatives.

The aluminum(III) triflate catalyzed three-component coupling reaction of alkynes, amines and phosphorylated aryl aldehydes to access phosphoryl quinoline derivatives has been developed. The reaction proceeds in a simple system without the use of transition metals, ligands or additives, thus making it attractive for the fast preparation of a variety of new potential N-P bidentate ligands.

Three-component coupling reaction for the synthesis of fully substituted triazoles: reactivity control of Cu-acetylide toward alkyl azides and diazo compounds

Herein, we report a Cu-catalyzed three-component coupling reaction of alkynes, azides, and diazo compounds for the synthesis of fully substituted triazoles.

Metal-free synthesis of alkynyl alkyl selenides via three-component coupling of terminal alkynes, Se, and epoxides

A metal-free three-component coupling reaction of alkynes, Se powder and epoxides is described, providing an efficient, straightforward route for the preparation of alkynyl alkyl selenides via a double C–Se bond formation process.

Recyclable Cu/C3N4 composite catalyzed AHA/A3 coupling reactions for the synthesis of propargylamines.

The heterogeneous Cu/C3N4 catalyst was found to be efficient for the synthesis of propargylamines using a three-component coupling reaction of alkynes, CH2Cl2 and amines (AHA) without additional base. Moreover, the catalyst also showed highly catalytic activity in the synthesis of C1-alkynylated tetrahydroisoquinolines (THIQs) via an A3 reaction of alkynes, aldehydes and THIQ. The Cu/C3N4-catalyzed multicomponent reactions exhibited good functional group tolerance in most examples. Furthermore, the easily prepared Cu/C3N4 catalyst could be recovered and reused conveniently over 5 times without losing catalytic activities.

Zn(OTf)2-mediated C[sbnd]H activation: An expeditious and solvent-free synthesis of aryl/alkyl substituted quinolines

Zinc(II) triflate catalyzed three-component coupling reactions of alkynes, amines and aldehydes leading to the formation of aryl/alkyl substituted quinolines has been described. Notably, the reaction proceeded efficiently and effectively without the use of ligand, co-catalyst, solvent or inert atmosphere. This robust solvent-free process operates under an ambient atmosphere and avoids the use of precious metals, hazardous solvents and harsh reaction conditions. This atom economic process eliminates the waste generated in the multistep synthesis. Additionally, a pseudo three-component Povarov reaction of amines and butanal proceeds under the same green conditions enabling the formation of 2,3-dialkyl quinolines.

Asymmetric Three-Component Coupling Reaction of Alkyne, Enone, and Aldehyde Catalyzed by Chiral Phebox Ruthenium Catalysts.

Catalytic asymmetric three-component coupling reactions of terminal alkynes, α,β-unsaturated ketones, and aldehydes were studied. The chiral ruthenium complexes containing bis(oxazolinyl)phenyl ligands were found to serve as efficient catalysts for a tandem reaction based on conjugate addition of terminal alkynes to α,β-unsaturated ketones and subsequent aldol reaction with aldehydes, giving β-hydroxyketone derivatives containing α-propargyl groups in high yields with moderate to good enantioselectivities. This method can produce various functional molecules from commercially available substrates in a one-pot procedure. The absolute configuration of the major product was determined by X-ray analysis. The control experiments suggested that a ruthenium enolate species generated in situ by conjugate addition could be involved as an intermediate for the aldol coupling with an aldehyde.

Production of Quaternary α-Aminonitriles by Means of Indium-Catalyzed Three-Component Reaction of Alkynes, Amines, and Trimethylsilyl Cyanide.

A novel synthesis of α-aminonitriles is described via an indium-catalyzed three-component coupling reaction of alkynes, amines, and trimethylsilyl cyanide (Me3SiCN). Hydroamination of alkynes with a subsequent nucleophilic addition of Me3SiCN resulted in a novel approach to quaternary α-aminonitrile derivatives.

One-Pot Multi-Component Route to Propargylamines Using Zinc Oxide Under Solvent-Free Conditions

In this paper, commercially available ZnO was found to be a highly effective catalyst for three-component coupling reactions of alkynes, aldehydes/or ketone and amines (A(3)-coupling) via C-H activation. The reactions could be applied to both aromatic and aliphatic aldehydes. Nearly quantitative yields of the desired products were obtained in most cases. No co-catalyst or activator is required, and water is the only by-product in the reactions. Heterogeneous nature of the catalyst made it reusable for further chemical reactions.

Synthesis of N-heterocyclic carbene silver and palladium complexes bearing bis(pyrazol-1-yl)methyl moieties

A series of N-heterocyclic carbene (NHC) silver and palladium complexes derived from N-[bis(pyrazol-1-yl)methyl]phenyl-N′-benzylimidazolium and N-[bis(pyrazol-1-yl)methyl]phenoxy- methyl-N′-benzylimidazolium salts have been synthesized and characterized by elemental analysis, NMR spectroscopy and single-crystal X-ray diffraction. The NHCs functionalized by bis(pyrazol-1-yl)methyl groups show three different coordination modes in these complexes. N-[Bis(pyrazol-1-yl)methyl]phenyl-N′-benzylimidazol-2-ylidene (L) and N-[bis(3,5-dimethylpyrazol-1-yl)methyl]phenyl-N′-benzylimidazol-2-ylidene (L′) act as monodentate ligands through the carbene carbon in cationic complexes [L2Ag][AgCl2] and [L′4Ag3Br2][AgBr2]. A bridging [C,N] bidentate coordination mode, through one pyrazolyl nitrogen and the carbene carbon to two palladium centers, was observed in macrocyclic complex L′2Pd2Br2. While in the coordination polymer [L2Ag2]n[PF6]2n and macrocyclic complex [L′2Ag2][PF6]2, L and L′ act as bridging [C,N,N] tridentate ligands through two pyrazolyl nitrogens and the carbene carbon. Although N-[bis(pyrazol-1-yl)methyl]phenoxymethyl-N′-benzylimidazol-2-ylidene (L″) also acts as a bridging [C,N] bidentate ligand in L″2Ag2Cl2 and a bridging [C,N,N] tridentate ligand in L″2Ag2X2 (X = BF4 or PF6), like L′ and L in L′2Pd2Br2 as well as [L2Ag2]n[PF6]2n and [L′2Ag2][PF6]2, respectively, an obvious difference among them is present. L″ prefers to coordinate to two silver atoms in a head (carbene)–to tail (nitrogen) coordination mode, while L and L′ show head (carbene)–to head (carbene) and tail (nitrogen)–to tail (nitrogen) coordination modes to two silver atoms. Additionally, these silver complexes exhibit good catalytic activity in the three-component coupling reaction of alkyne, aldehyde and amine forming propargylamines.

Synthesis and structural characterization of N-heterocyclic carbene silver complexes derived from N-ferrocenylmethyl-N′-(pyridylmethyl)imidazolium iodides

A series of N-heterocyclic carbene (NHC) silver complexes derived from N-ferrocenylmethyl-N′-(pyridylmethyl)imidazolium iodides have been synthesized, which show remarkable structural diversity. Reaction of N-ferrocenylmethyl-N′-(2-pyridylmethyl)imidazolium iodide with Ag2O yielded stair-like NHC–Ag complexes, whose assembly modes significantly depended on experimental conditions. Reaction of N-ferrocenylmethyl-N′-(4-pyridylmethyl)imidazolium iodide with Ag2O yielded a chain NHC–Ag complex with a repeating 16-membered macrocyclic unit. However, similar reaction of N-ferrocenylmethyl-N′-(3-pyridylmethyl)imidazolium iodide with Ag2O only gave a dimeric NHC–Ag complex through bridging iodide. In these NHC–Ag complexes, 2- and 4-pyridyl-substituted NHCs act as bridging bidentate ligands through the pyridyl nitrogen and carbene carbon atoms, while 3-pyridyl-substituted NHC only acts as a monodentate ligand through the carbene carbon atom. An I/Cl exchange reaction was observed upon recrystallization of these NHC silver iodides in CH2Cl2. These NHC–Ag complexes exhibited highly effective catalytic activity in the three-component coupling reaction of alkyne, aldehyde and amine to generate propargylamines.

Synthesis and catalytic activity of N-heterocyclic carbene silver complexes derived from 1-[2-(pyrazol-1-yl)phenyl]imidazole

Six mono- and dinuclear N-heterocyclic carbene (NHC) silver complexes based on 1-[2-(pyrazol-1-yl)phenyl]imidazole have been synthesized and characterized by elemental analysis and NMR spectroscopy, and their structures have been confirmed by single crystal X-ray diffraction. The N-functionalized carbene ligands exhibit versatile coordination modes in these silver complexes. N-[2-(3,5-Dimethylpyrazol-1-yl)phenyl]-N-benzylimidazol-2-ylidene (L) acts as a monodentate ligand through the carbene carbon in mononuclear LAgCl. While in dinuclear L2Ag2(PF6)2 and L′2Ag2(PF6)2 (L′ = N-[2-(pyrazol-1-yl)phenyl]-N-benzylimidazol-2-ylidene), L and L′ act as bridging bidentate ligands through the pyrazolyl nitrogen and the carbene carbon atoms to two silver atoms. Though, these two silver atoms have different coordination environments. In the former, one silver atom coordinates with two carbene carbons, the other coordinates with two pyrazolyl nitrogen atoms. In the latter, each silver atom coordinates with one carbene carbon and one pyrazolyl nitrogen atom, respectively. A dinuclear macrocyclic structure is observed in m-xylyl bridging tetradentate bis-NHC complexes L2Ag2(BF4)2 and (L)CH2C6H4CH2(L)Ag2(BF4)2, in which the coordination mode of carbene ligands is similar with that in L2Ag2(PF6)2. Preliminary catalytic tests show that all these complexes exhibit highly effective catalytic activity in the three-component coupling reaction of alkyne, aldehyde and amine forming propargylamines.

Efficient iron(iii)-catalyzed three-component coupling reaction of alkynes, CH2Cl2 and amines to propargylamines

An iron(III)-catalyzed three-component coupling reaction of alkynes, CH(2)Cl(2) and amines was developed for facile synthesis of propargylamines. Preliminary mechanism investigation using in situ FT-IR reveals that the crucial Fe-acetylide intermediate could be formed through C-H bond activation of alkynes thanks to cooperative effect of FeCl(3) and 1,1,3,3-tetramethylguanidine.

Propargylic amines constructed via copper-catalyzed three-component coupling of terminal alkynes, benzal halides and amines

A method for the synthesis of propargylic amines has been developed via an efficient copper(I)-catalyzed three-component coupling reaction of alkynes, benzal halides and amines through C–H and C-halogen activation. This reaction is conducted under mild conditions and provides an alternative method for the synthesis of propargylic amines.

Ni-Catalyzed Multicomponent Reaction of Vinylcyclopropane, Alkyne, and Me2Zn

A new nickel-catalyzed regio- and stereocontrolled three-component coupling reaction of alkynes, Me2Zn, and vinyloxacyclopropanes or vinylcyclopropanes to yield dienyl homo­allylalcohols and α-dienyl malonates is described.

ChemInform Abstract: Copper‐Catalyzed Three‐Component Coupling of Terminal Alkyne, Dihalomethane and Amine to Propargylic Amines.

The direct C―H and C―halogen activation for C―C bond formation is one of the most interesting reactions in organic chemistry. C―C bond formation using alkynes as a carbon nucleophilic source is a very useful method in synthesis. Herein, a copper(I) chloride catalyzed three-component coupling reaction of alkynes, dihalomethanes and amines through C―H and C—halogen activation to form propargylic amines under mild conditions has been established. The reaction can be conducted in water, in neat or in common organic solvents and it was applicable to both aromatic and aliphatic alkynes with good functional groups tolerance. It represents an excellent example of multi-component reactions (MCRs), provides an elegant method for the synthesis of propargylic amines which are frequent skeletal components and synthetically versatile key intermediates for the preparation of many nitrogen-containing biologically active compounds. From the mechanism point of view, this chemistry offers not only a new approach to propargylic amines with new C—C and C―N bonds formation through C―H and C―halogen activation, but also provides valuable mechanistic insight into the novel multi-component reactions.

Copper-Catalyzed Alkyne−Aryne and Alkyne−Alkene−Aryne Coupling Reactions

The efficient copper-catalyzed two-component coupling reaction of alkynes with arynes and the three-component coupling reaction of alkynes with allylic chlorides and arynes have been developed. Copper acetylide was postulated as a transient intermediate for the initiation of the coupling reactions.