Efficient Coupling Reaction Research Articles

Iron (III) Trichloride-Catalyzed One-Pot Three-Component Coupling of Indoles and Sodium Nitrite: A Convenient Synthesis of 2,3’-Bi(3H-indol)-3-one oximes

A simple, convenient and efficient three-component coupling (TCC) reaction toward a variety of (E)-2,3'-bi(3H-indol)-3-one oxime derivatives has been developed. This transformation proceeds via an iron (III)-catalyzed tandem coupling reaction between indoles and sodium nitrite. This methodology provides an alternative approach for easy access of (E)-2,3'-bi(3H-indol)-3-one oximes in good to excellent yields at room temperature.

An efficient synthesis of 2-(1-(E)-alkenyl)phenylphosphonates via Suzuki reaction of aryl nonaflates with (E)-1-alkenylboronates

An efficient and general Suzuki coupling reaction between 2-phosphonylaryl nonaflates and (E)-1-alkenylboronic pinacol esters using Pd(OAc)2/PPh3 as catalysts, K2CO3 as base and DMF as solvent has been developed. This strategy allows for convenient synthesis of twelve 2-(1-(E)-alkenyl)phenylphosphonates in good to excellent yields, most of which are not readily available by the previously reported Heck reaction of the same aryl nonaflates and terminal alkenes.

Catalytic Asymmetric Synthesis of Mixed 3,3′‐Bisindoles and Their Evaluation as Wnt Signaling Inhibitors

TOP class: The first efficient catalytic asymmetric coupling reaction of indoles with isatin-derived nitroalkenes was accomplished by using a complex consisting of a chiral imidazoline aminophenol ligand (1; see scheme) and Cu(OTf)(2). Biological activity of the newly formed chiral 3,3'-bisindoles was also confirmed in a Wnt signaling inhibitory assay.

Synthesis of bis(cyclic carbonate) and propylene carbonate via a one-pot coupling reaction of CO2, bisepoxide and propylene oxide

The effective transformation of carbon dioxide (CO2) into valuable products is promising in green and sustainable chemistry. The coupling reaction of CO2 with epoxides to afford cyclic carbonates is an atom-economic pathway for CO2 fixation. Many catalysts have been developed for this coupling reaction, however, very few of them were reported for the coupling reaction of CO2 with bisepoxides. This work describes an efficient one-pot coupling reaction of CO2, propylene oxide (PO) and bisepoxides without the addition of external organic solvents by using a nanolamellar zinc-cobalt double metal cyanide complex (Zn–Co(III) DMCC) as the catalyst and cetyltrimethyl-ammonium bromide (CTAB) as the co-catalyst. Propylene carbonate (PC) and bis(cyclic carbonate)s were obtained at the same time with high monomer conversions (PO: 93.6%, bisepoxides: 82.9%). The in situ produced PC acted as a good solvent for the coupling reaction of CO2 with bisepoxides. Two products could be easily separated by distillation or precipitation. The application of the obtained bis(cyclic carbonate)s was also preliminarily investigated. A non-isocyanate route for synthesizing polyurethanes with massive hydroxyl groups was proposed.

Gold(iii) stabilized over ionic liquids grafted on MCM-41 for highly efficient three-component coupling reactions

Two alkoxysilyl-modified ionic liquids (ILs) have been synthesized and further grafted onto mesoporous silica, MCM-41; these ionic liquids were used for dispersing AuCl3 catalysts that activate C-H bonds as required for the synthesis of propargylamines by coupling alkyne, aldehyde and amine (A(3) coupling) species. (29)Si NMR experiments demonstrate the formation of covalent bonds between alkoxysilyl-modified Bmim IL and the MCM-41 surface through silanol groups. The catalytic activities of Au(III)-supported MCM-41 and Au(III) homogeneous catalysts are lower than those obtained for the IL functionalized Au-MCM-41 solids when the same gold loading is considered. An interaction between Au(III) species and the IL is proposed for explaining the stabilization of gold(III) species. However, successive reaction cycles result in a decrease in the catalytic activity that has been explained on the basis of gold leaching.

One-step synthesis of Lycopodium alkaloid (-)-huperzine W via Suzuki-Miyaura coupling

The first total synthesis of (−)-huperzine W (1) has been achieved. Key element of the synthesis is a highly convergent assemblage for the two rings system of target molecule utilizing an efficient Suzuki-Miyaura coupling reaction between chiral iodide 2 and 2-allylpyrrolidinone 4. Evaluation of the AchE inhibition of synthetic huperzine W was also carried out. Electronic Supplementary MaterialSupplementary material is available for this article at 10.1007/s13659-012-0084-2 and is accessible for authorized users.

Graphene-Supported RuO2 Nanoparticles for Efficient Aerobic Cross-Dehydrogenative Coupling Reaction in Water

A cross-dehydrogenative coupling (CDC) reaction between tertiary amines and nitroalkanes has been realized under an oxygen atmosphere in water simply by using graphene-supported RuO(2) as the catalyst, which was made from water-soluble graphene with sulfonic groups and RuCl(3)·nH(2)O to form RuO(2)·nH(2)O nanocomposites in situ. In contrast to RuCl(3)·nH(2)O and RuO(2)·nH(2)O, the graphene-supported RuO(2) nanoparticles exhibited higher activity and stability for the aerobic CDC reaction in water.

Palladium-Catalyzed Desulfitative Arylation by C–O Bond Cleavage of Aryl Triflates with Sodium Arylsulfinates

An efficient Pd-catalyzed desulfitative coupling reaction of sodium arylsulfinates as arylation reagents by C-O bond cleavage of aryl triflates was developed. With only 2 mol % of Pd(OAc)(2) as catalyst and XPhos as ligand, the reaction proceeded well for a range of substrates.

Palladium supported on natural phosphate: Catalyst for Suzuki coupling reactions in water

The Suzuki–Miyaura coupling reaction is one of the most important synthetic catalytic reactions developed in the 20th century. However, the use of toxic organic solvents for this reaction still poses a scientific challenge and is an aspect of economical and ecological relevance. The use of water as a reaction medium overcomes this issue. In the present work, we described efficient Suzuki coupling reactions in water, without any phase transfer reagents and it is possible to couple challenging substrates like aryl chlorides. Notably, this protocol also works with ultra-low loading of catalyst with high turnover numbers.

Copper-catalyzed coupling of 1,2-dibromo-1-styrenes with sulfonamides for the preparation of ynamides

Ynamides were prepared through an efficient copper-catalyzed coupling reaction. In the presence of copper iodide, 1,10-phenanthroline, and Cs2CO3, the coupling reaction of 1,2-dibromo-1-styrenes with sulfonamides proceeded smoothly and generated the corresponding products with excellent isolated yields.

Synthesis of graft polymers with poly(isoprene) as main chain by living anionic polymerization mechanism

The graft polymers (poly(isoprene)-graft-poly(sty- rene)) (PI-g-PS), (poly(isoprene)-graft-poly(isoprene)) (PI-g-PI), (poly(isoprene)-graft-(poly(isoprene)-block-poly(styrene))) PI-g- (PI-b-PS), and (poly(isoprene)-graft-(poly(styrene)-block-poly(i- soprene))) PI-g-(PS-b-PI) with PI as main chain were synthe- sized through living anionic polymerization (LAP) mechanism and the efficient coupling reaction. First, the PI was synthesized by LAP mechanism and epoxidized in H2O2/HCOOH system for epoxidized PI (EPI). Then, the graft polymers with con- trolled molecular weight of main chain and side chains, and grafting ratios were obtained by coupling reaction between PILi þ ,P SLi þ ,P S-b-PILi þ , or PI-b-PSLi þ macroanions and the epoxide on EPI. The target polymers and all intermediates were well characterized by SEC, 1 HN MR, as well as their thermal properties were also evaluated by DSC. V C 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 50: 5144- 5150, 2012

Rapid and Efficient Coupling Reaction of Azo Dyes in a Continuous-Flow Microreactor

A convenient, rapid efficient method for the synthesis of azo dyes has been developed by coupling in a continuous-flow microreactor at room temperature. The advantage of this protocol is its continuousness, high efficiency and selectivity, short reaction time, and milder reaction conditions.

Fluorescence Switching of Imidazo[1,5-a]pyridinium Ions: pH-Sensors with Dual Emission Pathways

Imidazo[1,5-a]pyridinium ions are identified as highly emissive and water-soluble fluorophores accessed by an efficient three-component coupling reaction. Synthetic modifications of groups conjugated to the polyheterocyclic core are shown to profoundly impact the emission properties of these molecules. Notably, two structural isomers of functionalized imidazo[1,5-a]pyridinium ions were found to exhibit distinct de-excitation pathways, which are responsible for either a fluorescence turn-on or ratiometric response to pH change.

A simple route for the synthesis of 3,3,3′,3′-tetramethyl-2,3,3′,4′-tetrahydro-1H,1′H-[4,9′-bixanthene]-1,1′(2′H,9′H)-dione and its derivatives catalyzed by Mn2+ and other transition metal cations

A simple and efficient unusual coupling reaction of 9-(2-hydroxy-4,4-dimethyl-6-oxocyclohex-1-en-1-yl)-3,3-dimethyl-2,3,4,9-tetrahydro-1H-xanthen-1-one and its derivatives was accomplished in the presence of Mn2+, Cu2+, Cd2+, Hg2+, Fe3, or La3+. The structure elucidation was accomplished by IR, 1H NMR, 13C NMR, X-ray crystallography, UV–Visible and elemental analysis. A reaction mechanism is proposed.

ChemInform Abstract: Substituted Functional Olefins Through Lateral Sequential Lithiation/Silylation/Condensation of Tertiary Aromatic Amides: A Ligand for Phosphane‐Free Palladium‐Catalyzed Suzuki Coupling Reactions.

An unprecedented lateral sequential lithiation/silylation/condensation of tertiary aromatic amides has been developed that provides an efficient method to build up functional olefins in good yields. In addition, we have established an efficient and simple method that involves UV/Vis, fluorescence, and NMR analyses, to detect the interaction between transition-metal salts and functional olefins containing tertiary amides. This has enabled a highly efficient palladium-catalyzed Suzuki coupling reaction in the presence of tertiary aromatic amide-derived olefin ligands to be developed. The best results were obtained by employing 2 mol-% Pd(OAc)2, 2 equiv. Cs2CO3, a reaction temperature of 80 °C, dioxane as the solvent, and phosphane-free olefin 2d as ligand.

Highly efficient three-component coupling reaction catalyzed by gold nanoparticles supported on periodic mesoporous organosilica with ionic liquid framework

A novel gold nanoparticle supported periodic mesoporous organosilica with alkylimidazolium framework, Au@PMO-IL, was shown to be a highly active and recyclable catalyst for three-component coupling reaction of aldehyde, alkyne and amine to give the corresponding propargylamine.

An efficient nickel-catalyzed alkenylation of functionalized benzylic halides with alkenylaluminum reagents

Highly efficient and simple coupling reactions of benzylic bromides or chlorides with alkenylaluminum reagents catalyzed by NiCl(2)(PPh(3))(2) are reported. The coupling reactions proceed effectively at room temperature employing low loading of catalyst, 0.5 mol% for benzylic bromides having either electron-donating or -withdrawing substituents on the aromatic ring, affording coupling products in excellent yields of up to 94% in short reaction times. The coupling reactions of benzylic chloride require 5 mol% of the catalyst and a longer reaction time of 2 h.

ChemInform Abstract: 35 Years of Palladium‐Catalyzed Cross‐Coupling with Grignard Reagents: How Far Have we Come?

AbstractReview: ca. 80 refs.

Di(1H-benzo[d][1,2,3]triazol-1-yl)methane: An efficient ligand for copper and amine-free palladium-catalysed Sonogashira coupling reaction

An efficient Pd-catalysed Sonogashira coupling reaction was achieved in the absence of copper and amine with inorganic base using phosphene-free, air stable di(1H-benzo[d][1,2,3]triazol-1-yl)methane as ligand. The cross coupling of electron-rich, electron-defficient and hindered aryl halides with terminal alkynes afforded the internal alkynes in good to excellent yields. An efficient Pd-catalysed Sonogashira coupling reaction was achieved in the absence of copper and amine with inorganic base using phosphene-free, air stable di(1H-benzo[d][1,2,3]triazol-1-yl)methane as ligand. The cross coupling of electron-rich, electron-neutral, electron-defficient and hindered aryl halides with terminal alkynes afforded internal arylated alkynes in good to excellent yields.

Triflic Acid Catalyzed Reductive Coupling Reactions of Carbonyl Compounds with O‐, S‐, and N‐Nucleophiles

Highly efficient metal-free reductive coupling reactions of aldehydes and ketones with a range of nucleophiles in the presence of triflic acid (1-5 mol%) as the catalyst are presented. The reactions can be performed at ambient temperature without exclusion of moisture or air. A range of symmetrical and unsymmetrical ethers were obtained by this method in high yields and short reaction times. For the first time, the influence of additional functionalization has been studied. Furthermore, the formation of thioethers from ketones (by addition of unmodified thiols) and of sulfonamides from either aldehydes or ketones has been achieved under catalytic conditions.