A series of (NHC)Pd(R-allyl)Cl complexes [NHC: IPr = N,N'-bis(2,6-diisopropylphenyl)imidazol-2-ylidene, SIPr N,N'-bis(2,6-diisopropylphenyl)-4,5-dihydroimidazol-2-ylidene; R H, Me, gem-Me2, Ph] have been synthesized and fully characterized. When compared to (NHC)Pd(allyl)Cl, substitution at the terminal position allyl scaffold favors a more facile activation step. This translates into higher catalytic activity in Suzuki-Miyaura Buchwald-Hartwig reactions, allowing for coupling unactivated...

N-heterocyclic carbene ligands IMes (1), SIMes (2), IPr (3), SIPr (4), and ICy (5) react with Ni(CO)(4) to give the saturated tricarbonyl complexes Ni(CO)(3)(IMes) (8), Ni(CO)(3)(SIMes) (9), Ni(CO)(3)(IPr) (10), Ni(CO)(3)(SIPr) (11), Ni(CO)(3)(ICy) (12), respectively. The electronic properties of these have been compared their phosphine analogues general formula Ni(CO)(3)(PR(3)) by recording nu(CO) stretching frequencies. While all NHCs are better donors than tertiary phosphines, differences...

Complexes of iridium bearing NHC (NHC = N-heterocyclic carbene) ligands were synthesized and fully characterized. The series [(NHC)Ir(cod)Cl] obtained by simple cleavage [Ir(cod)Cl]2. complexes reacted with excess carbon monoxide, leading to [(NHC)Ir(CO)2Cl]. infrared carbonyl stretching frequencies these recorded quantify the electronic parameter ligands. X-ray diffraction study results allow for determination steric parameters within this series. These data comparison other ligand families.

A series of N-heterocyclic carbene Au(NHC)Cl complexes (NHC = IMes (1), SIMes (2), IPr (3), SIPr (4), IPrMe (5), IMe (6), ICy (7), IAd (8), ITPh (9)) have been synthesized either through reaction the corresponding imidazol-2-ylidene with [Au(SMe2)Cl] or by transmetalation respective Ag(I)−NHC complex in presence 1 equiv [Au(SMe2)Cl]. All gold(I) [Au(IMes)Cl] (10), [Au(SIMes)Cl] (11), [Au(IPr)Cl] (12), [Au(SIPr)Cl] (13), [Au(IPrMe)Cl] (14), [Au(IMe)Cl] (15), [Au(ICy)Cl] (16), [Au(IAd)Cl]...

Abstract This review describes the stabilization of various coordinatively unsaturated metal centers through incorporation N‐heterocyclic carbene (NHC) ligands. Such species are more thermally stable compared to ubiquitous tertiary phosphane systems. Although NHCs can be considered as mimics it has become apparent that there substantial differences between two ligand families. In general, NHC ligands much electron‐donating and sterically demanding than bulky We also discuss thermochemical...

Approaching El Dorado: A gold catalyst has been discovered that transfers a carbene unit from ethyl diazoacetate to aromatic substrates (see scheme) as well olefins, amines, and alcohols. The insertion of units into the CH bonds ring benzene, toluene, styrene is novel reaction. R=H, CH3, CHCH2; IPr=1,3-bis(diisopropylphenyl)imidazol-2-ylidene. Supporting information for this article (general experimental procedures product characterization data) available on WWW under...

A series of N-heterocyclic carbene (NHC)AgCl complexes [NHC = SIMes (1), IPr (2), SIPr (3), IPrMe (4), IMe (5), ICy (6), IAd (7), IsB (8), IDD (9), and TPh (10)] have been synthesized through reaction the imidazolium chloride salts with Ag2O or by direct metalation corresponding imidazol-2-ylidene in presence AgCl. All silver(I) [(SIMes)AgCl] (11), [(IPr)AgCl] (12), [(SIPr)AgCl] (13), [(IPrMe)AgCl] (14), [(IMe)AgCl] (15), [(ICy)AgCl] (16), [(IAd)AgCl] (17), [(IsB)AgCl] (18), [(IDD)AgCl]...

Reactivity and structural studies of unusual rhodium iridium systems bearing two N-heterocyclic carbene (NHC) ligands are presented. These capable intramolecular C-H bond activation lead to coordinatively unsaturated 16-electron complexes. The resulting complexes can be further by simple halide abstraction, leading 14-electron species an all-carbon environment. Saturation the vacant sites in 16- with carbon monoxide permits a comparison. DFT calculations show that these electrophilic metal...

The reaction of saturated and unsaturated imidazolium salts with nickelocene in refluxing THF results the formation NHC complexes general formula CpNi(NHC)Cl (NHC = SIMes (2), IPr (3), SIPr (4)). This protonation Cp2Ni was also tested using phosphonium salts, triethylphosphonium chloride leads to CpNi(PEt3)Cl (5). All compounds were characterized by NMR X-ray crystallography. catalytic activity aryl amination (Buchwald−Hartwig reaction) halide dehalogenation reactions.

A novel homogeneous catalytic system has been developed for the regioselective hydrothiolation of alkynes based on CpNi(NHC)Cl complexes (NHC = N-heterocyclic carbene). The designed catalyst was efficient selective addition a single ArS group to an alkyne and suitable synthesis vinylsulfides, without side reactions leading bis(arylthio)alkenes. Furthermore, this allowed S−H bond be performed with high regioselectivity (up 31:1) in good yields (61−87%). mechanistic study showed that reaction...

Novel cationic copper complexes bearing two N-heterocyclic carbenes (NHCs) have been synthesized and fully characterized. These air- moisture-stable were found to be highly active toward the hydrosilylation of ketones with varying steric congestion, aldehydes (even enolizable ones), esters.

The preparation of two series [Cu(NHC)2]X complexes (NHC=N-heterocyclic carbene, X=PF6 or BF4) in high yields from readily available materials is reported. These have been spectroscopically and structurally characterized. activity these cationic bis-NHC the hydrosilylation ketones was examined, both ligand counterion showed a significant influence on catalytic performance. Moreover, when compared with related [Cu(NHC)]-based systems, proved to be more efficient under similar reaction...

El Dorado angepeilt: Ein Goldkatalysator wird vorgestellt, der eine Carbeneinheit von Ethyldiazoacetat auf aromatische Substrate (siehe Schema) ebenso wie Olefine, Amine und Alkohole überträgt. Die Insertion Carbeneinheiten in die C-H-Bindungen des aromatischen Rings Benzol, Toluol Styrol ist neuartige Reaktion. R=H, CH3, CHCH2; IPr=1,3-Bis(diisopropylphenyl)imidazol-2-yliden.

Double take: A remarkable electron-deficient cationic dihydride complex [Ir(ItBu)2(H)2](PF6) (see crystal structure), prepared in high yield from the reaction of 14-electron [Ir(ItBu′)2](PF6) and H2 gas, shows a rare agostic interaction. The illustrates reversibility double, intramolecular CH activation process provides example "proposed" intermediate. ItBu: N,N′-di(tert-butyl)imidazol-2-ylidene.

Two new dicarbonyl N-heterocyclic carbene nickel(0) complexes of the type (NHC)2Ni(CO)2 (NHC = ICy, [N,N′-bis(cyclohexylimidazol)-2-ylidene (2), IMes [N,N′-bis(2,4,6-trimethylphenyl)imidazol)-2-ylidene] (3)) have been prepared by a substitution reaction (NHC)Ni(CO)2 ItBu [N,N′-bis(tert-butylimidazol)-2-ylidene], IAd [N,N′-bis(1-adamantylimidazol)-2-ylidene]) and 2 equivalents ICy or IMes. Single-crystal X-ray analyses confirmed monomeric 18-electron compositions [(ICy)2Ni(CO)2] (2)...

Abstract The reaction of Grignard compounds 1‐bromo‐2,4,6‐diisopropylbenzene ( 1 ) or 1‐bromo‐2,6‐dimethylbenzene 2 ), formed in situ, with 2,6‐dibromopyridine the presence a catalytic amount [(dme)NiBr ] (dme = 1,2‐dimethoxyethane) and tricyclohexylphosphane (1:2 ratio) leads to corresponding monoarylated bromopyridines. These bromopyridines undergo Pd‐catalysed aryl amination (Buchwald−Hartwig amination) 2,6‐diisopropylaniline giving rise...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTS to O and S linkage isomerization in sulfoxide complexes of pentaamminerutheniumA. Yeh, N. Scott, H. TaubeCite this: Inorg. Chem. 1982, 21, 7, 2542–2545Publication Date (Print):July 1, 1982Publication History Published online1 May 2002Published inissue 1 July 1982https://pubs.acs.org/doi/10.1021/ic00137a004https://doi.org/10.1021/ic00137a004research-articleACS PublicationsRequest reuse permissionsArticle Views331Altmetric-Citations70LEARN ABOUT...

Abstract Deprotonation of Ap*H {Ap*H = (2,6‐diisopropylphenyl)‐[6‐(2,4,6‐triisopropylphenyl)pyridin‐2‐yl]amine} and Ap'H {Ap'H (2,6‐diisopropylphenyl)‐[6‐(2,6‐dimethylphenyl)pyridin‐2‐yl]amine} using KH leads to polymeric [Ap*K] n [Ap'K] which undergo clean salt metathesis reactions with NdCl 3 in THF forming [Nd(Ap*)Cl 2 (THF) ] [Nd(Ap') ‐Cl(THF)], respectively. Ethylene polymerization activities the two chloro complexes (after activation MAO) were studied. Derivatization compounds proceeds...

Unsaturated NHCs of varying steric bulk undergo a series unusual oxidative addition and reductive elimination processes upon binding to the Pt(Me)2 fragment.

Abstract Salt elimination protocols using Ap*K {Ap*H = (2,6‐diisopropyl‐phenyl)‐[6‐(2,4,6‐triisopropyl‐phenyl)‐pyridin‐2‐yl]‐amine} lead to the rare earth aminopyridinato complex [Ap*LuCl 2 (thf) ], 4 . Results of X‐ray crystal structure analyses and corresponding single THF coordinated dimer are discussed. Ring‐opening polymerization ε‐caprolactone initiated by complexes [Ap*LaBr 3 , [Ap*YbI(thf) ] or in presence NaBH allows preparation, a short reaction time, α,ω‐dihydroxytelechelic...

Treatment of lanthanum metal with CH2Br2 or CH2I2 in tetrahydrofuran (thf) under ultrasound conditions yields the corresponding [LaX3(thf)4] (X = Br, I) complexes good yield. Recrystallization [LaBr3(thf)4] from 1,2-dimethoxyethane (dme) bis(2-methoxyethyl) ether (diglyme) generates [LaBr2(µ-Br)(dme)2]2 and [LaBr2(dig-lyme)2][LaBr4(diglyme)]. lanthanoid metals hexachloroethane dme [LnCl3(dme)2] (Ln La, Nd, Er Yb) acetonitrile [YbCl2(MeCN)5]2[YbCl3(MeCN)(-Cl)2YbCl3(MeCN)]. The reaction Yb...