5663-86-5

Upstream product

• 536-74-3 phenylacetylene 
• 693-02-7 hex-1-yne 
• 931-48-6 2-cyclohexylacetylene 
• 3240-11-7 Phenylacetylene-d1 
• 7223-38-3 N,N-Dimethylpropargylamin 
• 42268-68-8 allylpropargylamine 

Downstream Products

• 1621434-12-5 1-butyl-2-(hex-1-en-2-yl)-3-(4-methoxyphenyl)cyclobutene 

Relevant academic research and scientific papers

Rhodium(I)-NHC Complexes Bearing Bidentate Bis-Heteroatomic Acidato Ligands as gem-Selective Catalysts for Alkyne Dimerization

A series of Rh(κ2-BHetA)(η2-coe)(IPr) complexes bearing 1,3-bis-hetereoatomic acidato ligands (BHetA) including carboxylato (O,O), thioacetato (O,S), amidato (O,N), thioamidato (N,S), and amidinato (N,N), have been prepared by reacti

Active Iron(II) Catalysts toward gem-Specific Dimerization of Terminal Alkynes

We report the syntheses and catalytic activity of a series of piano-stool iron complexes with the general formula [FeClCp (NHC)] (where NHC = N-heterocyclic carbene) toward the gem-specific dimerization of terminal alkynes. In comparison to our first-gene

Pseudo-tetrahedral Rhodium and Iridium Complexes: Catalytic Synthesis of E-Enynes

The reactions of the rhodium(I) and iridium(I) complexes [M(PhBP3)(C2H4)(NCMe)] (PhBP3=PhB(CH2PPh2)3?) with alkynes have resulted in the synthesis of a new family of p

Selective Oligomerization and [2 + 2 + 2] Cycloaddition of Terminal Alkynes from Simple Actinide Precatalysts

A catalyzed conversion of terminal alkynes into dimers, trimers, and trisubstituted benzenes has been developed using the actinide amides U[N(SiMe3)2]3 (1) and [(Me3Si)2N]2An[κ2-(N,C)-CH2Si(CH3)N(SiMe3)] (An = U (2), Th (3)) as precatalysts. These complexes allow for preferential product formation according to the identity of the metal and the catalyst loading. While these complexes are known as valuable precursors for the preparation of various actinide complexes, this is the first demonstration of their use as catalysts for C-C bond forming reactions. At high uranium catalyst loading, the cycloaddition of the terminal alkyne is generally preferred, whereas at low loadings, linear oligomerization to form enynes is favored. The thorium metallacycle produces only organic enynes, suggesting the importance of the ability of uranium to form stabilizing interactions with arenes and related π-electron-containing intermediates. Kinetic, spectroscopic, and mechanistic data that inform the nature of the activation and catalytic cycle of these reactions are presented. (Chemical Equation Presented).

A series of pincer-ligated rhodium complexes as catalysts for the dimerization of terminal alkynes

A series of pincer complexes of Rh has been prepared and tested as catalysts for the dimerization of terminal alkynes. The pincers included aryl/bis(phosphinite) POCOP, aryl/bis(phosphine) PCP, and diarylamido/bis(phosphine) PNP ligands. RhI co

Pyridine-enhanced head-to-tail dimerization of terminal alkynes by a rhodium-N-heterocyclic-carbene catalyst

A general regioselective rhodium-catalyzed head-to-tail dimerization of terminal alkynes is presented. The presence of a pyridine ligand (py) in a Rh-N-heterocyclic-carbene (NHC) catalytic system not only dramatically switches the chemoselectivity from alkyne cyclotrimerization to dimerization but also enhances the catalytic activity. Several intermediates have been detected in the catalytic process, including the π-alkyne-coordinated RhI species [RhCl(NHC)(η2-HC ≡CCH2Ph)(py)] (3) and [RhCl(NHC){η2-C(tBu) ≡C(E)CH=CHtBu}(py)] (4) and the RhIII-hydride-alkynyl species [RhClH{-C ≡CSi(Me) 3}(IPr)(py)2] (5). Computational DFT studies reveal an operational mechanism consisting of sequential alkyne Ci￡ H oxidative addition, alkyne insertion, and reductive elimination. A 2,1-hydrometalation of the alkyne is the more favorable pathway in accordance with a head-to-tail selectivity. Control plan: Addition of pyridine to rhodium-N-heterocyclic- carbene catalysts not only switches the chemoselectivity from alkyne cyclotrimerization to dimerization, but also enhances the catalytic activity for the formation of 1,3-enynes (see figure). A 2,1-hydrometalation of the alkyne is the more favorable pathway calculated by DFT.

Palladium-catalyzed acylation and/or homo-coupling of aryl- and alkyl-acetylenes

Allyl or benzyl halides, through a Pd(0)-catalyzed reaction and under CO pressure, generate acyl-palladium/halides that, in the presence of a base and an aryl- and alkyl-acetylene, undergo nucleophilic acyl substitution giving conjugated acetylenic ketones. Diynes, resulting from alkyne/alkyne homo-coupling, were instead the main products in reactions performed without allyl or benzyl halides. Moreover, dimerization, trimerization, and cyclotrimerization reactions of acetylenes were observed in reaction carried out even without base.

Skeletal change in the PNP pincer ligand leads to a highly regioselective alkyne dimerization catalyst

A Rh complex of a bulky diarylamino-based PNP pincer ligand is a robust catalyst for the dimerization of terminal alkynes and highly selective for the trans-enyne product. The Royal Society of Chemistry 2006.

Regio- and stereoselective dimerization of terminal alkynes to enynes catalyzed by a palladium/imidazolium system

A Palladium/imidazolium chloride system has been used to mediate the dimerization of terminal alkynes to enynes. The combination of 1 mol % Pd(OAc)2 and 2 mol % IMes·HCl in the presence of Cs2CO3 as base shows high activit

Oligomerization and hydroamination of terminal alkynes promoted by the cationic organoactinide compound [(Et2N)3U][BPh4]

The three ancillary amido moieties in the cationic complex [(Et2N)3U][BPh4] are highly reactive and are easily replaced when the complex is treated with primary amines. The reaction of [(Et2N)3U][BPh4] with excess tBuNH2 allows the formation of the cationic complex [(tBuNH2)3(tBu-NH)3U][BPh4]. X-ray diffraction studies on the complex indicate that three amido and three amine ligands are arranged around the cationic metal center in a slightly distorted octahedral mer geometry. The cationic complex reacts with primary alkynes in the presence of external primary amines to primarily afford the unexpected cis dimer and, in some cases, the hydroamination products are obtained concomitantly. The formation of the cis dimer is the result of an envelope isomerization through a metal - cyclopropyl cationic complex. In the reaction of the bulkier alkyne tBuC≡CH with the cationic uranium complex in the presence of various primary amines, the cis dimer, one trimer, and one tetramer are obtained regioselectively, as confirmed by deuterium labeling experiments. The trimer and the tetramer correspond to consecutive insertions of an alkyne molecule into the vinylic CH bond trans to the bulky tert-butyl group. The reaction of (TMS)C≡CH with the uranium catalyst in the presence of EtNH2 followed a different course and produced the gem dimer along with the hydroamination imine as the major product. However, when other bulkier amines were used (iPrNH2 or tBuNH2) both hydroamination isomeric imines Z and E were obtained. During the catalytic reaction, the E (kinetic) isomer is transformed into the most stable Z (thermodynamic) isomer. The unique reactivity of the alkyne (TMS)C≡CH with the secondary amine Et2NH is remarkable because it afforded the trans dimer and the corresponding hydroamination enamine. The latter probably results from the insertion of the alkyne into a secondary metalamide bond, followed by protonolysis.