133496-99-8

Upstream product

• 768-60-5 4-methoxyphenylacetylen 
• 540-38-5 p-Iodophenol 
• 7223-38-3 N,N-Dimethylpropargylamin 
• 3989-14-8 (4-methoxyphenylethynyl)trimethylsilane 
• 696-62-8 para-iodoanisole 

Downstream Products

• 1143526-60-6 (1E)-1,3-di(4-anisyl)-2-phenylethynyl-1,3-butadiene 

Relevant academic research and scientific papers

Stereo- A nd regioselective dimerization of alkynes to enynes by bimetallic syn-carbopalladation

Enynes are important motifs in bioactive compounds. They can be synthesized by alkynea'alkyne couplings for which a number of mechanisms have been suggested depending on catalyst type and dominant product isomers. Regarding bimetallic pathways, hydrometalations and anti-carbopalladations have been discussed to account for the formation of geminally substituted and (Z)-configured enynes, respectively. Here we report a bimetallic alkynea'alkyne coupling that yields (E)-configured enynes. An unusual type of acetylide Pd bridging was found in putative catalytic intermediates which is arguably responsible for the regio- A nd stereochemical reaction outcome. Mechanistic studies suggest that a double μa'κ:η2 acetylide bridging enables a bimetallic syn-carbometalation. Interestingly, depending on the reaction conditions, it is also possible to form the geminal regioisomer as major product with the same catalyst. This regiodivergent outcome is explained by bi-versus monometallic reaction pathways.

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

Phosphinito palladium(ii) complexes as catalysts for the synthesis of 1,3-enynes, aromatic alkynes and ynones

An air-stable phosphinito palladium(ii) complex (Ph1-Phoxide) has been found to be an efficient catalyst in the formation of C-C bonds. The coupling of terminal alkynes formed gem-1,3-enynes as the only reaction products. Aromatic alkynes can be synthesized from the coupling of terminal alkynes and haloaromatic compounds (Sonogashira coupling). The phosphinito palladium(ii) complex also catalyses the coupling between acyl chlorides and terminal alkynes (Sonogashira coupling), furnishing ynones in excellent yields.

Reactivity switch enabled by counterion: Highly chemoselective dimerization and hydration of terminal alkynes

A counterion-controlled reactivity tuning in Pd-catalyzed highly chemoselective and regioselective dimerization and hydration of terminal alkynes is reported. The use of acetate as counterion favors the formation of an alkenyl alkynyl palladium intermediate which forms hitherto less reported 1,3-diaryl-substituted conjugated enynes after reductive elimination. Using chloride, which is a better leaving group, leads to anion exchange on the alkenylpalladium intermediate with hydroxide which after reductive elimination and tautomerization delivered the hydration products.

Carboxylate switch between hydro- and carbopalladation pathways in regiodivergent dimerization of alkynes

Experimental and theoretical investigation of the regiodivergent palladium-catalyzed dimerization of terminal alkynes is presented. Employment of N-heterocyclic carbene-based palladium catalyst in the presence of phosphine ligand allows for highly regio- and stereoselective head-to-head dimerization reaction. Alternatively, addition of carboxylate anion to the reaction mixture triggers selective head-to-tail coupling. Computational studies suggest that reaction proceeds via the hydropalladation pathway favoring head-to-head dimerization under neutral reaction conditions. The origin of the regioselectivity switch can be explained by the dual role of carboxylate anion. Thus, the removal of hydrogen atom by the carboxylate directs reaction from the hydropalladation to the carbopalladation pathway. Additionally, in the presence of the carboxylate anion intermediate, palladium complexes involved in the head-to-tail dimerization display higher stability compared to their analogues for the head-to-head reaction. Track changer: The regiodivergent palladium-catalyzed dimerization of terminal alkynes was studied. High regio- and stereoselectivity was achieved for both head-to-head and head-to-tail dimerization reactions. Computational studies suggest hydropalladation to favor head-to-head dimerization under neutral conditions. Addition of carboxylate anions switches the reaction from hydropalladation to carbopalladation pathway securing head-to-tail coupling (see scheme).

A ruthenium-based catalytic system with switchable selectivity between cyclotrimerization and enyne metathesis/Diels-Alder reactions of terminal alkynes

In this study, we report a practical catalytic system, [RuCl 2(p-cymene)]2/IPr (IPr: 1,3-bis(2,6 diisopropylphenyl) imidazol-2-ylidene), that can switch between cyclotrimerization and cross enyne metathesis. The cyclotrimerization reaction of phenylacetylene catalyzed by [RuCl2(p-cymene)]2 can be switched to enyne metathesis by the introduction of a sterically hindered N-heterocyclic carbene. The 1,3-diene formed during this reaction reacts with dienophiles to form the Diels-Alder adduct. A practical one-pot synthesis method, utilizing enyne metathesis/Diels-Alder reactions, was used to construct cyclic compounds in an efficient manner.

Rhodium-catalyzed dimerization of arylacetylenes and addition of malonates to 1,3-enynes

An 8-quinolinolato rhodium catalyst was found to be effective for head-to-tail selective dimerization of arylacetylenes. Formation of substituted cyclopentene and allene derivatives via alkyne dimerization and subsequent addition of malonates was also cat

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.

(Z)-Selective cross-dimerization of arylacetylenes with silylacetylenes catalyzed by vinylideneruthenium complexes

The vinylideneruthenium(II) complexes bearing bulky and basic tertiary phosphine ligands, RuCl2(=C=CHPh)L2 (L = PPr i3, PCy3), serves as a good catalyst precursor for (Z)-selective cross-dimerization between arylacetylenes and silylacetylenes in the presence of N-methylpyrrolidine. The Royal Society of Chemistry 2005.