Cross-coupling Reaction Of Terminal Alkynes Research Articles

Cu-Based ternary deep eutectic solvents for homo- and cross-coupling reactions of terminal alkynes

The Cu-DES-promoted Glaser-type homo- and cross-coupling of terminal alkynes under exogenous-ligand-free, base-free, and additive-free conditions is described.

Cu-catalyzed cross-coupling of chlorostibine with terminal alkynes to give Sb-alkynyl stibines and products transformation

Herein, we describe an efficient copper-catalyzed cross-coupling reaction of terminal alkynes with chlorostibine 1a to synthesize a variety of Sb-alkynyl stibines. Aryl, alkyl and heteroaryl acetylenes are all tolerated. This protocol shows good functional group tolerance and broad substrate scope. These obtained Sb-alkynyl stibines were utilized as effective coupling partners to prepare 1,2,3-triazoles. The catalytic mechanism is also proposed.

Synthesis of polyallenoates through copper-mediated cross-coupling of dialkynes and bis-α-diazoesters.

The copper-catalyzed cross-coupling of alkynes and α-diazoesters has been applied in the synthesis of polyallenoates for the first time. The polymerization tolerated various functional groups and afforded the polyallenoates with high molecular weight. With chiral guanidinium bromide as a ligand, the axial chirality of the allene moiety could be generated with high enantioselectivity during the polymerization process.

A carrier-free and recyclable protocol for the cross-coupling of terminal alkynes with arylboronic acids in H2O/TBAB

A new and recyclable protocol was developed for Pd(OAc)2-catalyzed the cross-coupling reaction of terminal alkynes with arylboronic acids using environmentally friendly H2O/TBAB as reaction medium. A series of cross-coupling products containing internal acetylenic bond can be obtained with good selectivity and yield. The Pd(OAc)2/H2O/TBAB system was stable in the Sonogashira-type cross-coupling reaction and could be used at least three cycles without considerable decrease in catalytic performance. The results suggest that the unsupported and recyclable systems can be extended to the other realm of CC bond formation in synthetic organic chemistry.

Fiber-supported Pd Catalysts for Cross-coupling Reaction of Aromatic and Aliphatic Terminal Alkynes

Increasing the efficiency of cross-coupling reaction under mild condition and easy catalyst separation is a key issue in the realistically chemical industry application. Here, we report that the fiber-supported Pd catalyst shows a high activity and selectivity for the cross-coupling reaction of terminal alkynes. The yield of the asymmetric 1,3-diyne can reach 83% at 80 °C and 4 h reaction time in N,N-dimethylacetamide (DMAc), and about 87% selectivity. XPS, EDS and SEM results show that Pd metal ions are successfully loaded onto the fiber surface and are reduced to produce active component of Pd (0) by terminal alkyne in reaction. We consider that Pd (0) is the active center of the catalytic cycle, the coordination of the fibers can stabilize Pd particles on the supports and increases the catalytic activity of Pd catalysts. Cu (I) plays a synergistic catalytic role. This study provides an alternative pathway for the high efficient cross-coupling reaction.

Cu(I)-Catalyzed Coupling of Bis(trimethylsilyl)diazomethane with Terminal Alkynes: A Synthesis of 1,1-Disilyl Allenes.

A Cu(I)-catalyzed cross-coupling reaction of terminal alkynes and bis(trimethylsilyl)diazomethane is reported. Mechanistically, the reaction is based on the recently developed cross-coupling reactions through metal-carbene migratory insertion. This reaction provides an efficient synthetic method for 1,1-disilyl allenes. Subsequent transformations of 1,1-disilyl allenes are investigated, which show diverse reactivities of these allenes.

A novel Zinc-catalyzed Cadiot-Chodkiewicz cross-coupling reaction of terminal alkynes with 1-bromoalkynes in ethanol solvent

A novel Et2Zn/L-proline catalyzed synthesis of symmetrical as well as unsymmetrical buta-1,3-diynes by the cross-coupling of terminal alkynes with 1-bromo alkynes in ethanol solvent was developed in good yields under simple and mild reaction conditions. The use of relatively non toxic and ecofriendly nature of Zn, inexpensive amino acid ligand L-proline and environmentally benign solvent EtOH make this protocol a better alternative for the synthesis of 1,3-diynes. The scope and limitations of this protocol were investigated.

ChemInform Abstract: Cu(I)‐Catalyzed Cross‐Coupling of Terminal Alkynes with Trifluoromethyl Ketone N‐Tosylhydrazones: Access to 1,1‐Difluoro‐1,3‐enynes.

C–C Bond formation and β-F elimination have been achieved in a Cu(I)-catalyzed cross-coupling reaction of terminal alkynes and trifluoromethyl ketone N-tosylhydrazones. The reaction represents an efficient synthesis of 1,1-difluoro-1,3-enyne derivatives. Mechanistically, the migratory insertion of the copper carbene intermediate leads to the C–C bond formation, which is followed by C–F bond cleavage.

Cu(I)-Catalyzed Cross-Coupling of Terminal Alkynes with Trifluoromethyl Ketone N-Tosylhydrazones: Access to 1,1-Difluoro-1,3-enynes.

C-C Bond formation and β-F elimination have been achieved in a Cu(I)-catalyzed cross-coupling reaction of terminal alkynes and trifluoromethyl ketone N-tosylhydrazones. The reaction represents an efficient synthesis of 1,1-difluoro-1,3-enyne derivatives. Mechanistically, the migratory insertion of the copper carbene intermediate leads to the C-C bond formation, which is followed by C-F bond cleavage.

Catalytic Sonogashira couplings mediated by an amido pincer complex of palladium

This work describes the efficacy of [PNP]PdCl (1a), where [PNP]− = bis(2-diphenylphosphinophenyl)amide, as a catalyst precursor for Csp–Csp2 bond-forming cross-coupling reactions of terminal alkynes with aryl halides in the presence of copper bromide and aliphatic amines in ethereal solutions under mild conditions. This catalysis is compatible with acetylenes that are alkyl, alkenyl, (hetero)aryl, or silyl substituted and aryl iodides or bromides that are electronically activated, neutral, or deactivated. The low reaction constants of 0.82(6) and 0.97(7) obtained from Hammett plots of competitive reactions employing electronically distinct aryl iodides and terminal alkynes, respectively, are likely suggestive of irrelevance of the rate-determining step in these catalytic transformations to oxidative addition of aryl halides or generation of mono-substituted acetylides. In sharp contrast, reactions employing a phosphorus-bound isopropyl derived 1b gave rather unsatisfactory results, highlighting a profound phosphorus substituent effect on this aryl alkynylation catalysis.

ChemInform Abstract: Transition‐Metal‐Free Sonogashira‐Type Cross‐Coupling of Alkynes with Fluoroarenes.

A novel, inexpensive, and efficient palladium-, copper-, ligand-, and amine-free Sonogashira-type cross-coupling reaction of terminal alkynes with unreactive aryl fluorides in the presence of sodium, sodium methoxide, and calcium hydroxide under the assistance of a Grignard reagent was developed. A plausible mechanism was also suggested.

Transition-Metal-Free Sonogashira-Type Cross-Coupling of Alkynes with Fluoroarenes

A novel, inexpensive, and efficient palladium-, copper-, ligand-, and amine-free Sonogashira-type cross-coupling reaction of terminal alkynes with unreactive aryl fluorides in the presence of sodium, sodium methoxide, and calcium hydroxide under the assistance of a Grignard reagent was developed. A plausible mechanism was also suggested.

ChemInform Abstract: A Green Synthetic Route to Imides from Terminal Alkynes and Amides by Simple Solid Catalysts.

AbstractAn efficient and new green synthesis of imides is developed that combines a cupric hydroxide‐catalyzed cross‐coupling reaction of terminal alkynes and amides and the Sn‐W mixed oxide‐catalyzed regioselective hydration of the ynamide formed.

Copper-Mediated Oxidative Cross-Coupling Reaction of Terminal Alkynes with α-Silyldifluoromethylphosphonates: An Efficient Method for α,α-Difluoropropargylphosphonates

A copper-mediated oxidative cross-coupling reaction of terminal alkynes with readily available α-silyldifluoromethylphosphonates under mild conditions has been developed. This method allows for an efficient synthesis of a series of synthetically useful α,α-difluoropropargylphosphonates with excellent functional group compatibility.

ChemInform Abstract: Development of Novel Synthetic Organic Reaction Based on Activation by a Trivalent Indium Salt

AbstractReview: ca. 50 refs.

3価のインジウム塩による活性化を基盤とした新しい有機合成反応の開発

Indium (III) salt has attracted considerable attention in synthetic organic chemistry due to its low toxicity, high stability under aqueous conditions, and strong tolerance to oxygen- and nitrogen containing functional groups. Hence, our interest focused on developing a novel synthetic organic reaction based on activation by the trivalent indium halide. Herein we report the following reactions: (i) an InBr3-Et3N reagent system-promoted alkynylation of aldehydes or N,O-acetals leading to various propargylic alcohols or amines; (ii) a Pd(II)-InBr3 reagent system-catalyzed cross-coupling reaction of terminal alkynes with aryl iodides leading to the functionalized alkyne derivatives; (iii) InBr3-catalyzed intramolecular cyclization of various ethynylanilines producing a variety of indole derivatives; (iv) InBr3-promoted intermolecular dimerization of the ethynylanilines without a substituent on a terminal alkyne affording polysubstituted quinolines; (v) an InBr3-Et3SiH reagent system-promoted chemoselective deoxygenation of esters, amides or nitrobenzenes producing the corresponding highly valuable compounds.

Palladium-Catalyzed Cross-Coupling of Electron-Poor Terminal Alkynes with Arylboronic Acids under Ligand-Free and Aerobic Conditions

Palladium-catalyzed cross-coupling reaction of terminal alkynes with arylboronic acids has been described. In the presence of Pd(OAc)(2) and Ag(2)O, a variety of terminal alkynes, including electron-poor terminal alkynes, smoothly underwent the reaction with numerous boronic acids to afford the corresponding internal alkynes in moderate to good yields. Moreover, this methodology was applied to the synthesis of 1H-isochromenes and diynes. It is noteworthy that the reaction proceeds under ligand-free and relative lower loading Pd conditions, and the maximal TONs (turnover numbers) of the reaction are up to 720,000.

Palladium-Catalyzed Aerobic Oxidative Cross-Coupling Reactions of Terminal Alkynes with Alkylzinc Reagents

With air as the oxidant, terminal alkynes can be directly cross-coupled with alkylzinc reagents in the presence of a Pd catalyst at room temperature. CO was found to be critical in gaining high chemical yields and selectivities. A wide range of alkynes and alkylzinc reagents were tested, and good to excellent yields were obtained.

New Activators for the Coupling Reaction of Terminal Alkynes with Organic Halides.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Efficient Palladium-Catalyzed Homocoupling Reaction and Sonogashira Cross-Coupling Reaction of Terminal Alkynes under Aerobic Conditions

An efficient method for palladium-catalyzed homocoupling reaction of terminal alkynes in the synthesis of symmetric diynes is presented. The results showed that both Pd(OAc)(2) and CuI played crucial roles in the reaction. In the presence of 2 mol % Pd(OAc)(2), 2 mol % CuI, 3 equiv of Dabco, and air, homocoupling of various terminal alkynes afforded the corresponding symmetrical diynes in moderate to excellent yields, whereas low yields were obtained without either Pd(OAc)(2) or CuI. Moreover, high TONs (turnover numbers; up to 940 000 for the reaction of phenylacetylene) for the homocoupling reaction were observed. Under similar reaction conditions, cross-coupling of 1-iodo-4-nitrobenzene with phenylacetylene was also carried out smoothly in quantitative yield. However, the presence of CuI disfavored the palladium-catalyzed Sonogashira cross-coupling reactions of the less active aryl iodides and bromides. In the presence of 0.01-2 mol % Pd(OAc)(2), a number of aryl iodides and bromides were coupled with terminal alkynes in good to excellent yields. It is noteworthy that this protocol employs mild, efficient, aerobic, copper-free, and ligand-free conditions.