A series of alkylammonium-imidazolium chloride salts [RImH(CH2)nNMe2]Cl·HCl (R = Me, t-Bu, Mes; n 2, 3) have been prepared by alkylation 1-substituted imidazole compounds with the corresponding chloro-alkyl-dimethylamine hydrochloride. These are precursors for synthesis a library rhodium(I) complexes containing amino-alkyl functionalized N-heterocyclic carbene (NHC) ligands hemilabile character varying substituent on heterocyclic ring and length linker dimethylamino moiety. The...

A series of neutral and cationic rhodium iridium(I) complexes based on hemilabile O-donor- N-donor-functionalized NHC ligands having methoxy, dimethylamino, pyridine as donor functions have been synthesized. The fragment is coordinated to the iridium center in [Ir(cod)(MeImR)]+ (R = pyridin-2-ylmethyl, 3-dimethylaminopropyl) but remains uncoordinated [MBr(cod)(MeImR)], [M(NCCH3)(cod)(MeImR)]+ (M Rh, Ir; R 2-methoxyethyl 2-methoxybenzyl) [IrX(cod)(MeImR)] (X Br, pyridin-2-ylmethyl; X Cl,...

Abstract The borrowing hydrogen methodology allows for the use of alcohols as alkylating agents CC bond forming processes offering significant environmental benefits over traditional approaches. Iridium(I)‐cyclooctadiene complexes having a NHC ligand with O‐ or N‐functionalised wingtip efficiently catalysed oxidation and β‐alkylation secondary primary in presence base. cationic complex [Ir(NCCH 3 )(cod)(MeIm(2‐ methoxybenzyl))][BF 4 ] (cod=1,5‐cyclooctadiene, MeIm=1‐methylimidazolyl) rigid...

Oxidized multiwall carbon nanotubes (CNT) were covalently modified with appropriate hydroxyl-ending imidazolium salts using their carboxylic acid groups. Characterization of the imidazolium-modified samples through typical solid characterization techniques, such as TGA or XPS, allows for determination 16 wt % in CNT-1 and 31 CNT-2 amount imidazolic fragments nanotubes. The imidazolium-functionalized materials used to prepare nanohybrid containing iridium N-heterocyclic carbene (NHC)-type...

Copper(I) [Cu2(μ-Br)2(tBuImCH2pyCH2L)] n (L = OMe, NEt2, NHtBu) compounds supported by flexible functionalized NHC-based polydentate ligands have been prepared in a one-pot procedure reacting the corresponding imidazolium salt with an excess of copper powder and Ag2O. An X-ray diffraction analysis has revealed that [Cu2(μ-Br)2(tBuImCH2pyCH2NEt2)] is linear coordination polymer formed bimetallic [Cu(μ-Br)]2 units linked lutidine-based NHC-py-NEt2 ligand, which acts as heteroditopic ligand...

The catalytic activity in the hydrosilylation of terminal alkynes by unsaturated hydrido iridium(III) compound [IrH(κ3-hqca)(coe)] (1), which contains rigid asymmetrical dianionic ONO pincer ligand 8-oxidoquinoline-2-carboxylate, has been studied. A range aliphatic and aromatic 1-alkynes efficiently reduced using various hydrosilanes. Hydrosilylation linear hex-1-yne oct-1-yne gives a good selectivity toward β-(Z)-vinylsilane product, while for bulkier t-Bu-C≡CH reverse β-(E)-vinylsilane...

Graphene oxide has been prepared from an industrial coke-like waste. The morphology of this material (GO-CW) is similar to that standard graphene (GO-G), although its surface more defects. Both materials were used prepare hybrid NHC-Ir(I)/graphene materials, consisting molecular Ir(NHC) complexes covalently anchored the through NHC moiety, following two different synthetic routes: (a) direct electrografting previously synthesized aniline-functionalized imidazole-2-ylidene-Ir(I) complex, and...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHydrodesulfurization (HDS) Model Systems. Opening, Hydrogenation, and Hydrodesulfurization of Dibenzothiophene (DBT) at Iridium. First Case Catalytic HDS DBT in Homogeneous PhaseClaudio Bianchini, M. Victoria Jimenez, Andrea Meli, Simonetta Moneti, Francesco Vizza, Veronica Herrera, Roberto A. Sanchez-DelgadoCite this: Organometallics 1995, 14, 5, 2342–2352Publication Date (Print):May 1, 1995Publication History Published online1 May 2002Published...

The synthesis of unbridged biscarbene iridium(I) [Ir(cod)(MeIm∩Z)2]+ complexes having N- or O-functionalized NHC ligands (∩Z = 2-methoxybenzyl, pyridin-2-ylmethyl, quinolin-8-ylmethyl) is described. molecular structures the show an antiparallel disposition carbene that minimize steric repulsions between bulky substituents. However, were found to be dynamic in solution, due restricted rotation about C(carbene)–Ir bond results two interconverting diasteromers different dispositions...

The cyclometalated Rh(III)–NHC compounds [Cp*RhI(C,C′)-Triaz] (Triaz = 1,4-diphenyl-3-methyl-1,2,3-triazol-5-ylidene) and [Cp*RhI(C,C′)-Im] (Im 1-phenyl-3-methyl-imidazol-2-ylidene) are efficient catalysts for the hydrosilylation of terminal alkynes with complete regio- stereoselectivity toward thermodynamically less stable β-(Z)-vinylsilane isomer at room temperature in chloroform or acetone. Catalyst shows a superior catalytic performance terms activity has been applied to range linear...

An Ir–NHC compound catalyzes the borrowing-hydrogen reduction of nitroarenes into<italic>N</italic>-methyl amines with methanol through a direct mechanism.

The zwitterionic compound [Cp*RhCl{(MeIm)2CHCOO}] is an efficient catalyst for the hydrosilylation of terminal alkynes with excellent regio- and stereoselectivity toward less thermodynamically stable β-(Z)-vinylsilane isomer under mild reaction conditions. A broad range linear 1-alkynes, cycloalkyl acetylenes, aromatic undergo HSiMe2Ph to afford corresponding β-(Z)-vinylsilanes in quantitative yields short times. aliphatic HSiEt3 slower, resulting a slight decrease selectivity product, which...

The iridium(I) complexes [IrBr(cod)(κC-tBuImCH2PyCH2NRR')] (NRR' = NEt2, NHtBu) have been prepared by reaction of the corresponding functionalized imidazolium salt with appropriate dinuclear compound [Ir(µ-OR)(cod)]2 (R OMe, OEt). These compounds react H2(g) (5 bar) to afford pincer iridium(III) dihydrido [IrBrH2(κ3C,N,N'-tBuImCH2PyCH2NRR')] in good yields. efficiently catalyzed β-alkylation a series secondary alcohols and N-alkylation range aniline derivatives primary alcohols,...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHomogeneous Reactions of Thiophenes with Transition Metals: A Modeling Approach for Elucidation the Hydrodesulfurization Mechanism and an Effective Method Synthesis Unusual Organosulfur CompoundsClaudio Bianchini, Piero Frediani, Veronica Herrera, M. Victoria Jimenez, Andrea Meli, Luis Rincon, Roberto Sanchez-Delgado, Francesco VizzaCite this: J. Am. Chem. Soc. 1995, 117, 15, 4333–4346Publication Date (Print):April 1, 1995Publication History...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Catalytic Transformation of Benzo[b]thiophene to 2-Ethylthiophenol by a Soluble Rhodium Complex: The Reaction Mechanism Involves Ring Opening Prior HydrogenationClaudio Bianchini, Veronica Herrera, M. Victoria Jimenez, Andrea Meli, Roberto Sanchez-Delgado, and Francesco VizzaCite this: J. Am. Chem. Soc. 1995, 117, 33, 8567–8575Publication Date (Print):August 1, 1995Publication History Published online1 May 2002Published inissue 1 August...

The diamidonaphthalene-bridged diiridium tetrahydride [Ir2{μ-1,8-(NH)2C10H6}(μ-H)H3(NCMe)(PiPr3)2] (1) reacts with an excess of internal alkynes such as diphenylacetylene, 2-butyne, or 1-phenyl-1-propyne to give the diiridium(I) alkene compounds [Ir2{μ-1,8-(NH)2C10H6}{η2-Z-CH(R)CHR'}2(PiPr3)2] (R, R' = Ph, 4; R, Me, 5; and R 6), respectively. bis-Z-alkenyl reaction intermediate [Ir2{μ-1,8-(NH)2C10H6}(μ-H)H{Z-C(Ph)CHPh}2(NCMe)(PiPr3)2] (3) has been isolated characterized in case...

A series of cationic complexes [Rh(diene){Ph2P(CH2)nZ}][BF4] (diene = 1,5-cyclooctadiene (cod), tetrafluorobenzobarralene (tfb) or 2,5-norbonadiene (nbd)) containing functionalized phosphine ligands the type Ph2P(CH2)nZ (n 2, 3; Z OMe, NMe2, SMe) have been prepared and characterized. These shown a great catalytic activity for phenylacetylene (PA) polymerization. Catalyst screening optimization determined superior performance P,N-functionalyzed ligand, [Rh(diene){Ph2P(CH2)3NMe2}][BF4] cod, 5;...

Experimental and theoretical studies give support for an iridium-catalyzed C–N bond formation.

Thermally partially reduced graphene oxide has been covalently modified with 3-methyl-4-phenyl-1,2,3-triazolium salts making use of the epoxy functionalities on carbon nanomaterial. Characterization functionalized materials through adequate solid characterization techniques, particularly X-ray photoelectron spectroscopy (XPS), allows one to follow stepwise building up triazolium fragments attached wall via covalent C–N linkage. The hydroxyl-triazolium-functionalized have used prepare rhodium...

A series of novel functionalized phosphines hemi­labile character, R2P(CH2)nZ, have been prepared from diaryl­phosphines using several synthetic methodologies. The methods include the alkylation lithium diarylphosphide or (di­arylphosphino)borane adducts with halogenoalkanes, X(CH2)nZ, and photochemical hydrophosphination suitable allyl vinyl derivatives, H2C=CHZ H2C=CHCH2Z, white light. range R2PH (R = Bn, 4-MeOC6H4, 4-MeC6H4, 2-MeC6H4, Ph, 4-F3CC6H4) has used in order to tune electronic...

The oxidative addition of phenylacetylene to the monohydrido diiridium complex [Ir2(μ-1,8-(NH)2naphth)H(CO)2(PiPr3)2](CF3SO3) (2) and diiridium(II) species [Ir2(μ-1,8-(NH)2naphth)(CF3SO3)2(CO)2(PiPr3)2] (3) has been studied. kinetic product 2 is dihydridoalkynyl [Ir2(μ-1,8-(NH)2naphth)(μ-C⋮CPh)H2(CO)2(PiPr3)2](CF3SO3) (4), in which alkynyl ligand bridges iridium atoms a μ,η1:η2-coordination mode. Compound 4 isomerizes acetone solution give hydride-bridged...

The bis-imidazolium salt, 1,1-bis(N-methylimidazolium) acetate bromide, is a convenient precursor for the synthesis of zwitterionic iridium(I) [Ir(cod){(MeIm)2CHCOO}] and cationic iridium(III) [IrH(cod){(MeIm)2CHCOO}]+ compounds (MeIm = 3-methylimidazol-2-yliden-1-yl) having carboxylate-functionalized bis(NHC) ligand. compound catalyzes hydrogenation CO2 to formate in water using NEt3 as base, reaching turnover numbers approximately 1500. Reactivity studies have shown that activation...