Reaction Of Aryl Iodides Research Articles

Experimental and Mechanistic Exploration of Zn‐Catalyzed Sonogashira–type Cross‐Coupling Reactions

AbstractOne of the most straightforward methods for the synthesis of disubstituted alkynes is the transition metal catalyzed Sonogashira‐type cross‐coupling reactions. Herein we report a detailed study of our recent research on the first Zn‐catalyzed protocol for C(sp2)–C(sp) cross‐coupling reaction of aryl iodides with terminal alkynes. A wide range of functional groups were tolerated in the reaction and both functionally and structurally diverse diaryl acetylenes were prepared efficiently using this protocol. The reaction mechanism for the Zn‐catalyzed Sonogashira‐type coupling reaction was investigated by means of density functional theory (DFT) methods on a model system. The calculations were performed using hybrid Becke Perdew Functional (BPV86) in conjugation with LANL‐2DZ basis set and found that the reaction pathway involves oxidative addition and reductive elimination mechanism.

ChemInform Abstract: A Atom‐Efficient Cross‐Coupling Reaction of Aryl Iodides with Triarylbismuths Catalyzed by Immobilization of Palladium(II)‐Schiff Base Complex in MCM‐41.

Abstract The first phosphine-free heterogeneous atom-efficient cross-coupling of aryl iodides with triarylbismuths was achieved in NMP using K 2 CO 3 as base at 110 °C in the presence of 2 mol % of an MCM-41-immobilized palladium(II)-Schiff base complex [MCM-41-N,N-Pd(OAc) 2 ], yielding a variety of unsymmetrical biaryls in good to excellent yields. This new heterogeneous palladium catalyst exhibits high catalytic activity and can be recovered by a simple filtration of the reaction solution and recycled for at least 10 consecutive trials without any decreases in activity. Our system not only avoids the use of phosphine ligands, but also solves the basic problem of palladium catalyst recovery and reuse.

ChemInform Abstract: Iron‐Catalyzed Sonogashira Type Cross‐Coupling Reaction of Aryl Iodides with Terminal Alkynes in Water under Aerobic Conditions.

AbstractA green protocol is presented for the iron catalyzed coupling reaction in water and under aerobic conditions.

Facile preparation of highly stable and active hybrid palladium nanoparticles: effectual, reusable and heterogeneous catalyst for coupling reactions

Palladium nanoparticles were supported on a bed of Fe3O4@‐NH2@Murexide using a simple and efficient method, and characterized using Fourier transform infrared spectroscopy, X‐ray diffraction, scanning and transmission electron microscopies and inductively coupled plasma optical emission spectrometry. The catalytic system showed great efficiency in cross‐coupling reaction of aryl iodides and arylboronic acid and in Sonogashira cross‐coupling reaction in the green solvent EtOH–H2O (1:1). The isolation and recovery of the catalyst were simple and facile and it could be used for several successive Suzuki–Miyaura coupling and Sonogashira cross‐coupling reactions. Copyright © 2016 John Wiley & Sons, Ltd.

ChemInform Abstract: Versatile Route to Arylated Fluoroalkyl Bromide Building Blocks.

AbstractThe reaction of aryl iodides with a copper complex generated in situ from corresponding silver complex (V) gives rise to desired aryl octafluorobutyl bromides (VII) in moderate to good yields.

Iron‐Catalyzed Sonogashira Type Cross‐Coupling Reaction of Aryl Iodides with Terminal Alkynes in Water under Aerobic Conditions

AbstractThe first protocol for the iron‐catalyzed Sonogashira type coupling of aryl iodides with terminal alkynes using exclusively water as the solvent under aerobic conditions is reported for the synthesis of diaryl alkynes. We found that the catalytic system comprised of FeCl3.6H2O and 1,10‐phenanthroline is an efficient catalyst towards these coupling reactions. This methodology is applicable to a wide range of substituted aryl iodides with heteroaryl and sterically hindered groups and terminal aryl alkynes including heteroaryl alkynes with good yields. The present protocol provides economical and environmental advantages over other traditional methods due to the low cost and ecofriendly nature of the catalyst. Most importantly, the greenest solvent available, water, alone is used as the solvent for the first time for Iron‐catalyzed Sonogashira type coupling reaction underlining the ecofriendly nature of the process.

Tridentate Hydroxy-Functionalised MCM-41-Immobilised Copper(I) Complex as an Efficient and Recyclable Catalyst for Coupling of Aryl Iodides with Thiols

The C–S coupling reaction of aryl iodides with thiols was achieved at 110 °C in DMF/dioxane (V/V, 1:9) in the presence of a tridentate hydroxy-functionalised MCM-41-immobilised copper(I) complex [MCM-41-3OH-CuI] with Cs2CO3 as base to afford a variety of diaryl sulfides in good to excellent yields. The MCM-41-3OH-CuI catalyst can be easily recovered by a simple filtration and reused for at least six times without significant loss of activity.

ChemInform Abstract: Assemblies of Copper Ferrite and Palladium Nanoparticles on Silica Microparticles as a Magnetically Recoverable Catalyst for Sonogashira Reaction under Mild Conditions.

Copper ferrite and palladium nanoparticles assembled on silica microparticles are prepared successfully and characterized by scanning electron microscopy, transmission electron microscopy, electron-dispersive X-ray analysis, X-ray diffraction, thermogravimetric analysis, atomic absorption spectroscopy, and infrared studies. The catalyst is applied effectively for the Sonogashira coupling reaction of aryl iodides and bromides under heterogeneous and phosphine-free reaction conditions. The reactions proceed at 50 °C with a low loading of palladium catalyst. The magnetically recoverable catalyst is recycled successfully for five consecutive runs with very small drops in catalytic activity.

ChemInform Abstract: Polystyrene Supported Thiopseudourea Pd(II) Complex: Applications for Sonogashira, Suzuki—Miyaura, Heck, Hiyama and Larock Heteroannulation Reactions.

AbstractA new polystyrene‐supported Pd‐complex is developed and employed as catalyst for a range of typical Pd‐catalyzed cross‐coupling reactions of aryl iodides and bromides.

ChemInform Abstract: Copper Catalyzed Synthesis of 1‐Aryl‐1,2,3‐triazoles from Aryl Iodides, Alkynes, and Sodium Azide.

AbstractThe catalyst is reused five times with slightly decreasing yields.

Palladium-catalyzed/norbornene-mediated ortho-amination/N-tosylhydrazone insertion reaction: an approach to the synthesis of ortho-aminated vinylarenes.

ortho-Aminated vinylarene derivatives were obtained via a reaction of aryl iodides, N-benzoyloxyamines, and N-tosylhydrazones. This approach involves a palladium-catalyzed, norbornene-mediated ortho-amination/N-tosylhydrazone insertion reaction. In this transformation, one C-N bond and one C-C bond are formed and an amine group is introduced at the ortho position successfully.

Asymmetric functional organozinc additions to aldehydes catalyzed by 1,1'-bi-2-naphthols (BINOLs).

ConspectusChiral alcohols are ubiquitous in organic structures. One efficient method to generate chiral alcohols is the catalytic asymmetric addition of a carbon nucleophile to a carbonyl compound since this process produces a C–C bond and a chiral center simultaneously. In comparison with the carbon nucleophiles such as an organolithium or a Grignard reagent, an organozinc reagent possesses the advantages of functional group tolerance and more mild reaction conditions. Catalytic asymmetric reactions of aldehydes with arylzincs, vinylzincs, and alkynylzincs to generate functional chiral alcohols are discussed in this Account.Our laboratory has developed a series of 1,1′-bi-2-naphthol (BINOL)-based chiral catalysts for the asymmetric organozinc addition to aldehydes. It is found that the 3,3′-dianisyl-substituted BINOLs are not only highly enantioselective for the alkylzinc addition to aldehydes, but also highly enantioselective for the diphenylzinc addition to aldehydes. A one-step synthesis has been achieved to incorporate Lewis basic amine groups into the 3,3′-positions of the partially hydrogenated H8BINOL. These H8BINOL–amine compounds have become more generally enantioselective and efficient catalysts for the diphenylzinc addition to aldehydes to produce various types of chiral benzylic alcohols. The application of the H8BINOL–amine catalysts is expanded by using in situ generated diarylzinc reagents from the reaction of aryl iodides with ZnEt2, which still gives high enantioselectivity and good catalytic activity. Such a H8BINOL–amine compound is further found to catalyze the highly enantioselective addition of vinylzincs, in situ generated from the treatment of vinyl iodides with ZnEt2, to aldehydes to give the synthetically very useful chiral allylic alcohols.We have discovered that the unfunctionalized BINOL in combination with ZnEt2 and Ti(OiPr)4 can catalyze the terminal alkyne addition to aldehydes to produce chiral propargylic alcohols of high synthetic utility. The reaction was conducted by first heating an alkyne with ZnEt2 in refluxing toluene to generate an alkynylzinc reagent, which can then add to a broad range of aldehydes at room temperature in the presence of BINOL and Ti(OiPr)4 with high enantioselectivity. It was then found that the addition of a catalytic amount of dicyclohexylamine (Cy2NH) allows the entire process to be conducted at room temperature without the need to generate the alkynylzincs at elevated temperature. This BINOL–ZnEt2–Ti(OiPr)4–Cy2NH catalyst system can be used to catalyze the reaction of structurally diverse alkynes with a broad range of aldehydes at room temperature with high enantioselectivity and good catalytic activity.The work described in this Account demonstrates that BINOL and its derivatives can be used to develop highly enantioselective catalysts for the asymmetric organozinc addition to aldehydes. These processes have allowed the efficient synthesis of many functional chiral alcohols that are useful in organic synthesis.

ChemInform Abstract: Microwave‐Assisted Cu2O‐Catalyzed One‐Pot Synthesis of Symmetrical Diaryl Selenides from Elemental Selenium.

AbstractA microwave‐assisted method is developed for the copper‐catalyzed reaction of aryl iodides with elemental selenium to give diaryl selenides in good yields.

ChemInform Abstract: Cu‐Catalyzed Synthesis of Diaryl Thioethers and S‐Cycles by Reaction of Aryl Iodides with Carbon Disulfide in the Presence of DBU.

AbstractThe one‐pot method for the title syntheses uses the cheap and easy to‐handle carbon disulfide under ligand‐free conditions.

ChemInform Abstract: Iron‐Catalyzed Cross‐Coupling Reaction: Recyclable Heterogeneous Iron Catalyst for Selective Olefination of Aryl Iodides in Poly(ethylene glycol) Medium.

AbstractAn iron‐based catalyst supported on acac‐functionalized silica is prepared and evaluated as a heterogeneous catalyst for Mizoroki‐Heck reactions of aryl iodides with olefins.

Synthesis of β-Aryl Ketones by Heck Arylation of Allylic Alcohols Catalysed by a Mcm-41-Supported Bidentate Nitrogen Palladium Complex

The Heck arylation reaction of aryl iodides with allylic alcohols catalysed by an mesoporous silica (MCM-41)-supported bidentate nitrogen palladium complex [MCM-41-2N-Pd(OAc)2] proceeded smoothly in the presence of tetrabutylammonium chloride (TBAC) in DMF to afford β-aryl ketones in good to excellent yields. This heterogeneous palladium catalyst can be recovered by simple filtration and reused several times without any decrease in activity.

Palladium-Catalyzed Synthesis of Symmetrical Biaryls Under Microwave Irradiation and Conventional Heating

The activity of the [Pd{C6H4(CH2N(CH2Ph)2)}(µ-Br)]2 complex was investigated in the synthesis of symmetrical biaryls under both conventional and microwave irradiation conditions, and their results were compared. This complex is efficient, stable, and not sensitive to air or moisture and is a catalyst for the homo-coupling reaction of aryl iodides, bromides, and even chlorides. The products were produced in excellent yields in short reaction times using a catalytic amount of [Pd{C6H4(CH2N(CH2Ph)2)(µ-Br)]2 complex in N-methylpyrolidine (NMP) at 130 °C. In comparison to conventional heating conditions, the reactions under microwave irradiation gave better yields in shorter reaction times.

Cu-Catalyzed Synthesis of Diaryl Thioethers and S-Cycles by Reaction of Aryl Iodides with Carbon Disulfide in the Presence of DBU

Diaryl thioethers and S-cycles were obtained on the basis of the copper-catalyzed reaction of carbon disulfide and aryl iodides in the presence of DBU. This reaction enables the one-pot synthesis of diaryl thioethers by employing cheap, available, and easy-to-handle carbon disulfide with aryl iodides. The reaction was successfully employed in the construction of sulfur-containing cyclic molecules.

Preparation of Recoverable Pd Catalysts for Carbonylative Cross‐Coupling and Hydrogenation Reactions

AbstractWe report on the synthesis, characterization and catalytic performance of new, supported PdII and Pd0 catalysts. The catalysts are characterized by TEM, XRD, FTIR, X‐ray photoelectron spectroscopy, and vibrating sample magnetometry. The catalysts are found to be active in both forms, PdII and Pd0, for the carbonylative cross‐coupling reaction of aryl iodides with arylboronic acids, and for the hydrogenation of aromatic nitro‐ and unsaturated compounds. The newly developed catalysts are prepared by a synthetic strategy that is similar to the one used for other supported catalysts but are easier to recover—they can be recycled by magnetic separation from liquid phase reactions—and can be used for at least 5 consecutive trials without any decrease in activity.

Solid supported palladium(0) nano/microparticle: a ligand-free efficient recyclable heterogeneous catalyst for mono- and β,β-double-Heck reaction

Solid supported palladium nano/microparticles were found to be active catalysts to perform mono- and β,β-double-Heck reactions. Different β-unsubstituted and substituted alkenes including acrylate, methacrylate, crotonate, styrene, acrylonitrile, and acrylamide were investigated successfully for mono- and β,β-double-Heck reactions with aryl iodide under milder reaction condition. One-pot β,β-double-Heck reaction of aryl iodides with α,β-unsaturated ester, amide, nitrile, and styrene derivatives were also performed under standard reaction conditions. Wide functional group tolerance, easy catalyst recovery, and recyclability up to twelve times without significant loss of catalytic activity added extra importance to the present process.