Alkynes In Water Research Articles

Pd-catalyzed coupling of vinyl iodides with alkynes in water

Pd-catalyzed coupling of vinyl iodides with alkynes in water

Copper iodide nanoparticles on poly(4-vinyl pyridine) as new and green catalyst for multicomponent click synthesis of 1,4-disubstituted-1,2,3-triazoles in water

Poly(4-vinyl pyridine) supported nanoparticle of copper(I) iodide is reported as a green and recyclable catalyst for the regioselective synthesis of 1,4-disubstituted-1H-1,2,3-triazoles from benzyl halides, sodium azide and terminal alkynes in water. This catalyst can be recovered by simple filtration and recycled up to 8 consecutive runs without any loss of its efficiency.

Copper iodide nanoparticles on poly(4-vinyl pyridine): A new and efficient catalyst for multicomponent click synthesis of 1,4-disubstituted-1,2,3-triazoles in water

Polymer supported nanoparticles of copper(I) iodide is reported as a new, efficient and recyclable catalyst for the regioselective multicomponent synthesis of 1,4-disubstituted-1H-1,2,3-triazoles from α-halo ketones, sodium azide and terminal alkynes in water. This catalyst can be recovered by simple filtration and recycled up to 8 consecutive runs without losing its efficiency. ► Click synthesis of triazole derivatives ► High product yields with short reaction times ► Heterogeneous catalysis and recyclability of the catalyst

Aqueous Organometallic Chemistry of mer-Ir(H)2(PMe3)3X Complexes

A series of Ir(H)2(PMe3)3X compounds where X = various anionic ligands has been synthesized. The most studied of this group with X = Cl has been characterized fully, including by X-ray crystallography. For X = Cl, PhCO2–, dissolution in water results in the establishment of the equilibrium Ir(H)2(PMe3)3X + H2O ⇌ [Ir(H)2(PMe3)3(H2O)]+X–, which is responsible for the reaction of these compounds with unsaturated organic compounds. Reactions between the dihydrides and alkynes in water as well as the thermodynamics of the aqueous equilibrium are discussed.

Water-Soluble N-Heterocyclic Carbene Platinum(0) Complexes: Recyclable Catalysts for the Hydrosilylation of Alkynes in Water at Room Temperature

The synthesis and characterization of new water-soluble platinum(0) complexes bearing sulfonated N-heterocyclic carbene (NHC) and divinyltetramethylsiloxane (dvtms) ligands are described. These complexes, of the general formula (NHC)Pt(dvtms), are active and recyclable catalysts for the hydrosilylation of phenylacetylene and other alkynes at room temperature in water. Our findings indicate that the NHC–Pt(0) bonds are reasonably stable under these catalytic conditions, although hydrolysis is observed at temperatures above 80 °C in pure water.

Light-induced iodoperfluoroalkylation reactions of carbon–carbon multiple bonds in water

In this work we have undertaken the radical-induced addition of 1-iodo-n-perfluorobutane onto electron-rich alkenes, alkenes with electron withdrawing groups, and alkynes in water, initiated photochemically. The lack of hydrogen donor (i.e.: (Me3Si)3SiH) in our reaction medium facilitates a Halogen Atom-transfer reaction (HAT), affording the respective perfluorobutylated alkyl and alkenyl halides (iodides) in good yields in water. We have also found that water exerts a relevant solvent effect on the rates of perfluoroalkyl radical additions onto double and triple bonds. The stereoselectivity of the radical addition reaction of alkynes is studied. The novelty of this work relies on the photochemical generation of fluorinated radicals in water, and the Halogen Atom-transfer addition reactions of iodoperfluoroalkanes onto carbon–carbon unsaturated bonds in water induced by light.

Multicomponent Click Synthesis of 1,2,3-Triazoles from Epoxides in Water Catalyzed by Copper Nanoparticles on Activated Carbon

Copper nanoparticles on activated carbon have been found to effectively catalyze the multicomponent synthesis of β-hydroxy-1,2,3-triazoles from a variety of epoxides and alkynes in water. The catalyst is easy to prepare, reusable at a low copper loading (0.5 mol %), and exhibits higher catalytic activity than some commercially available copper sources. The regio- and stereochemistry of the reaction has been revised and unequivocally established on the basis of X-ray crystallographic analyses. An NMR experiment has been implemented for the rapid and unmistakable determination of the regiochemistry of the process. Some mechanistic aspects of the reaction have been also undertaken which unveil the participation of copper(I) acetylides.

ChemInform Abstract: “On‐Water” Michael‐Type Addition Reactions Promoted by PhSeZnCl.

AbstractThe Michael‐type addition of (II) to alkenes and alkynes in water presents an effective and eco‐friendly alternative to existing methods.

ChemInform Abstract: Cross‐Linked Polymer‐Supported Palladium‐Catalyzed Carbonylative Sonogashira Coupling Reaction in Water.

Abstract A cross-linked polymer-supported ionic liquid immobilized palladium catalyst, which is prepared by reaction of the Pd(OAc)2 with copolymer of 3-butyl-1-vinylimidazolium iodide and divinylbenzene, was well characterized and employed as an effective heterogeneous catalyst for carbonylative Sonogashira coupling reaction of aryl iodides with terminal alkynes in water, affording the corresponding α,β-alkynyl ketones in good to excellent yields. The catalytic system not only solves the basic problem of homogeneous palladium catalyst recovery and reuse but also avoids the use of toxic phosphine ligands. The stability of supported palladium was also discussed.

ChemInform Abstract: Efficient Copper‐Catalyzed Sonogashira Couplings of Aryl Halides with Terminal Alkynes in Water.

AbstractGenerally, good yields are obtained with aryl iodides under conditions A) and various functionalities are tolerated.

Insights into Supported Copper(II)‐Catalyzed Azide‐Alkyne Cycloaddition in Water

AbstractCross‐linked polymeric ionic liquid material‐supported copper (Cu‐CPSIL), imidazolium‐loaded Merrifield resin‐supported copper (Cu‐PSIL) and silica dispersed CuO (CuO/SiO2), were prepared and proved to be efficient catalysts for the one‐pot synthesis of 1,4‐disubsituted‐1,2,3‐triazoles by the reaction of alkyl halides with sodium azide and terminal alkynes in water at room temperature. Moreover, these supported copper catalysts were recovered quantitatively from the reaction mixture by simple filtration and reused for five consecutive recycles without significant loss of catalytic activity. Among the three immobilized copper catalysts, Cu‐CPSIL exhibited excellent catalytic activity for the reaction of aliphatic bromides, sodium azide and terminal alkynes. The differences in the catalytic performances of the catalysts could be ascribed to the copper dispersion and the interaction between copper and the supports. In addition, water was used as the reaction media and the proton provider, the latter was found to be very important for the reaction. The XPS results suggested that the supported Cu(II) catalysts were reduced to catalytic Cu(I) species via alkynes homocoupling reaction. By means of IR and ESI‐MS studies, a possible mechanism of cycloaddition based on the reduction of Cu(II) to Cu(I) species was proposed.

A reusable CuSO4 · 5H2O/cationic 2,2′-bipyridyl system catalyzed homocoupling of terminal alkynes in water

A reusable CuSO4 · 5H2O/cationic 2,2′-bipyridyl system catalyzed the homocoupling reaction of terminal alkynes in water using I2 as the additive in the presence or absence of tetrabutylammonium bromide, giving the 1,3-diynes in good to high yields. After reaction, the residual aqueous solution could be reused several times. Copyright © 2011 John Wiley & Sons, Ltd.

ChemInform Abstract: Zeo‐Click Chemistry: Copper(I)—Zeolite‐Catalyzed Cascade Reaction: One‐Pot Epoxide Ring‐Opening and Cycloaddition.

AbstractCopper(I)‐modified zeolites are efficient and reusable heterogeneous catalysts for the one‐pot condensation of epoxides with sodium azide and terminal alkynes in water at room temperature.

Efficient Copper-Catalyzed Sonogashira Couplings of Aryl Halides with Terminal Alkynes in Water

An efficient copper-catalyzed method has been developed for Sonogashira couplings of aryl halides with terminal alkynes in water. The protocol uses inexpensive CuBr as the catalyst, 1,10-phenanthroline as the ligand, tetrabutylammonium bromide (TBAB) as the phase-transfer catalyst, environmentally friendly water as the solvent, and various internal alkynes were synthesized in good to excellent yields.

Mannich reaction of secondary amines, aldehydes and alkynes in water using Cu/C nanoparticles as a heterogeneous catalyst

The use of 2 mol% of Cu/C nanoparticles, as an easily accessible and inexpensive heterogeneous catalyst, promoted a one-pot three-component condensation of an amine, aldehyde, and an alkyne in water to produce the corresponding propargylamine in good to high yields. This method was proved to be applicable to a wide range of substrates and is especially practical for the synthesis of new azacrown ether derivatives. The catalyst was quantitatively recovered from the reaction by a simple filtration and reused for at least ten times with almost consistent activity.

Cross-linked polymer supported palladium catalyzed carbonylative Sonogashira coupling reaction in water

A cross-linked polymer-supported ionic liquid immobilized palladium catalyst, which is prepared by reaction of the Pd(OAc)2 with copolymer of 3-butyl-1-vinylimidazolium iodide and divinylbenzene, was well characterized and employed as an effective heterogeneous catalyst for carbonylative Sonogashira coupling reaction of aryl iodides with terminal alkynes in water, affording the corresponding α,β-alkynyl ketones in good to excellent yields. The catalytic system not only solves the basic problem of homogeneous palladium catalyst recovery and reuse but also avoids the use of toxic phosphine ligands. The stability of supported palladium was also discussed.

ChemInform Abstract: Rhodium(I)/Cationic 2,2′‐Bipyridyl‐Catalyzed [2 + 2 + 2] Cycloaddition of α,ω‐Diynes with Alkynes in Water under Air.

Abstract A simply performed procedure for the [Rh(cod)Cl]2/cationic 2,2′-bipyridyl system-catalyzed [2+2+2] cycloaddition of α,ω-diynes with terminal and internal alkynes was achieved in water under air at 60 °C. The reaction proceeded smoothly with 1 equiv α,ω-diynes and 3 equiv alkynes in the presence of 20 mol % KOH for 1 h or 9 h, resulting in the formation of tri- and tetra-substituted benzene derivatives in moderate to high yields. After separation of the organic products by extraction, the residual aqueous solution could be reused for further reactions until complete degradation of its catalytic activity.

ChemInform Abstract: Reusable Polymer‐Supported Terpyridine Copper Complex for [3 + 2] Huisgen Cycloaddition in Water.

A polymer-supported terpyridine copper(I) complex was prepared and found to promote the Huisgen [3+2] cycloaddition reaction between azides and alkynes in water to give the corresponding triazoles with up to 87% isolated yield. This catalyst was recovered and reused several times without any loss in catalytic activity.

Rhodium(I)/cationic 2,2′-bipyridyl-catalyzed [2+2+2] cycloaddition of α,ω-diynes with alkynes in water under air

A simply performed procedure for the [Rh(cod)Cl]2/cationic 2,2′-bipyridyl system-catalyzed [2+2+2] cycloaddition of α,ω-diynes with terminal and internal alkynes was achieved in water under air at 60 °C. The reaction proceeded smoothly with 1 equiv α,ω-diynes and 3 equiv alkynes in the presence of 20 mol % KOH for 1 h or 9 h, resulting in the formation of tri- and tetra-substituted benzene derivatives in moderate to high yields. After separation of the organic products by extraction, the residual aqueous solution could be reused for further reactions until complete degradation of its catalytic activity.

Copper-Free Sonogashira Coupling in Water with a PS-PEG Palladium Complex

An amphiphilic polystyrene-poly(ethylene glycol) (PS-PEG) resin-supported palladium phosphine complex was applied to the Sonogashira coupling of aryl halides with terminal alkynes in water. Thus, the PS-PEG palladium complex 1 was prepared from PS-PEG-NH2, diphenylphosphinobenzoic acid, and [PdCl(π-C3H5)]2 according to the reported procedures (Tetrahedron Lett. 1997, 38, 3557). The Sonogashira coupling of iodobenzene 2 with phenyl­acetylene 3 was performed with 5 mol% palladium of the polymeric catalyst 1 in water to give the diphenylacetylene 4 in 99% yield.