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The synthesis and characterization of two dinuclear and five tetranuclear gold(I) complexes bearing the 2,6-bis(diphenylphosphinomethyl)pyridine diphosphane ligand (DPPMPY) are herein reported. The reaction between the dinuclear complexes, DPPMPY(AuCl)

Many transition-metal complexes MLn decompose diazo compounds N2-CR1R2 generating metal-carbenes LnM-CR1R2 which transfer the carbene group to other substrates, constituting an important tool in organic synthesis. All previous reports have shown that the CR1R2 fragment at the metal-carbene remains intact from the parent diazo compound. Herein we report the detection and isolation of a monosubstituted copper carbene where the CR1R2 ligand has undergone a modification from the initial diazo reagent. When TpMsCu(THF) (TpMs = hydrotris(3-mesityl)pyrazolylborate ligand) was reacted with N,N-diethyl diazoacetamide [N2-C(H)(CONEt2)], the stable copper carbene TpMsCu-C(H)(NEt2) was isolated, resulting from a decarbonylation process, with carbon monoxide being trapped as TpMsCu(CO). The simultaneous observation of products derived from the intramolecular carbene insertion reaction into C–H bonds demonstrates that the expected TpMsCu-C(H)(CONEt2) complex is also formed. Experimental data, DFT calculations, and microkinetic models allow us to propose that the latter undergoes CO loss en route to the former., Funding for open access charge: Universidad de Huelva / CBUA, Funding for open access charge: Universidad de Huelva / CBUAWe dedicate this work to the memory of Professor Victor Riera, one of the pioneers of organometallic chemistry in Spain. We acknowledge financial support from the Ministerio de Ciencia e Innovación (CTQ2017-82893-C2-1-R, CTQ2017- 87792-R, P. O. Feder UHU-1260216 and P. O. Feder UHU- 1254043, and Red Intecat CTQ2016-81923-REDC)

A multigram method for the preparation of thallium trispyrazolylborate complexes is described., The authors wish to thank MINECO for financial support (CTQ2014-52769-C03-01 and CTQ2015-73693-JIN). A.P. thanks MEC for the FPU fellowship.

Nickel catalysis is gaining in popularity in recent years, mostly within the area of cross-coupling. However, unlike Pd, the mechanisms of Ni-catalyzed C–C and C–heteroatom bond forming reactions have been much less studied, in particular when N-heterocyclic carbenes are used as ligands. Here, we present a thorough study of the mechanism of C–N cross-coupling reactions catalyzed by an NHC-Ni complex. Focusing on the coupling of 2-chloropyridines with indole catalyzed by [(IPrNi(styrene)2] (IPr = N,N′-bis(2,6-diisopropylphenyl)imidazol-2-ylidene), we have examined each of the elementary steps: i.e., oxidative addition, ligand substitution, and reductive elimination. All relevant catalytic intermediates have been isolated and structurally characterized by both spectroscopic and crystallographic methods. Kinetic studies have revealed that the reductive elimination is the rate-limiting step. Catalyst deactivation is related to the formation of unproductive dinuclear pyridyl-bridged NHC-NiII species, which can...

Two iridium(III) complexes containing a C,N-bidentate pyridyl-triazolylidene ligand were prepared that are structurally very similar but differ in their pendant substituent. Whereas complex 1 contains a non-coordinating pyridyl unit, complex 2 has a phenyl group on the triazolylidene substituent. The presence of the basic pyridyl unit has distinct effects on the catalytic activity of the complex in the oxidative dehydrogenation of benzylic amines, inducing generally higher rates, higher selectivity towards formation of imines versus secondary amines, and notable quantities of tertiary amines when compared to the phenyl-functionalized analogue. The role of the pyridyl functionality has been elucidated from a set of stoichiometric experiments, which demonstrate hydrogen bonding between the pendant pyridyl unit and the amine protons of the substrate. Such Npyr···H-N interactions are demonstrated by X-ray diffraction analysis, 1H NMR, and IR spectroscopy, and suggest a pathway of substrate bond-activation that involves concerted substrate binding through the Lewis acidic iridium center and the Lewis basic pyridyl site appended to the triazolylidene ligand, in agreement with ligand–metal cooperative substrate activation.

The mild generation of nitrogen-centred radicals from N–F reagents has become a convenient synthetic tool. This methodology provides access to the aminative difunctionalisation of alkenes and alkynes and the radical ring-opening of cyclopropanes, among other similar transformations. This review article aims to provide an overview of recent developments of such processes involving radical reactions and N–F reagents using copper-based catalysts., We thank Ministerio de Economía y Competitividad (MINECO) (CTQ2017-82893-C2-1-R) and Universidad de Huelva (PO FEDER 2014-2020 UHU-1254043) for grants.

Tris(pyrazolyl)methane ligands (Tpmx) have been for years a step behind their highly popular boron-anionic analogues, the tris(pyrazolyl)borate ligands (Tpx). However, in the last decade the development of new members of this family of ligands has boosted a number of contributions albeit their use in coordination chemistry. This fact has also triggered the application of metal-Tpmx complexes as catalysts for a range of organic transformations, particularly with group 11 metals. The main structural features of complexes containing the TpmxM (M = Cu, Ag, Au) unit and their success as catalysts in a variety of reactions under homogeneous or heterogeneous conditions are presented., We thank MINECO for support with Grant CTQ2017-82893-C2-1-R

The dual function of the N-F bond as an effective oxidant and subsequent nitrogen source in intramolecular aliphatic C-H functionalization reactions is explored. Copper catalysis is demonstrated to exercise full regio- and chemoselectivity control, which opens new synthetic avenues to nitrogenated heterocycles with predictable ring sizes. For the first time, a uniform catalysis manifold has been identified for the construction of both pyrrolidine and piperidine cores. The individual steps of this new copper oxidation catalysis were elucidated by control experiments and computational studies, clarifying the singularity of the N-F function and characterizing the catalytic cycle to be based on a copper(I/II) manifold., We thank MINECO for Grants CTQ2017-82893-C2-1-R, CTQ2017-87792-R, CTQ2017-88496-R, COST Action CA15106 “C–H Activation in Organic Synthesis (CHAOS)”and Red Intecat (CTQ2016-81923-REDC).

Tris(pyrazolyl)borates (Tpx) have become one of the most broadly used polydentate anionic ligands in coordination chemistry and catalysis since Trofimenko introduced them in 1966. Herein we present a review of the main structural features of Group 11 metal complexes with Tpx ligands, as well as their catalytic properties, can be controlled by ligand steric and electronic factors., We thank MINECO for funding (Grant CTQ2017-82893-C2-1-R).We thank MINECO for Grant CTQ2017-82893-C2-1-R.

The functionalization of the primary sites of alkanes is one of the more challenging areas in catalysis. In this context, a novel effect has been discovered that is responsible for an enhancement in the reactivity of the primary C-H bonds of alkanes in a catalytic system. The copper complex Cu(NCMe) (=hydrotris{[3,5-bis(trifluoromethyl)-4-bromo]-pyrazol-1-yl}borate) catalyzes the functionalization of CnH2n+2 with ethyl diazoacetate upon inserting the CHCO2Et unit into C-H bonds. In addition, the selectivity of the reaction toward the primary sites significantly increased relative to that obtained in neat alkane upon using supercritical carbon dioxide as the reaction medium. This was attributed to the effect of the carbon dioxide molecules that withdraw electron density from the fluorine atoms of the ligand, which enhances the electrophilic nature of the metal center. DFT studies validated this proposal.

The copper complex Tp(CF3)2,BrCu(NCMe) (1, Tp(CF3)2,Br = hydrotris((3,5-bis(trifluoromethyl)-4-bromo)-pyrazol-1-yl)borate) catalyzes the insertion of the CHCO2Et group (from ethyl diazoacetate N2CHCO2Et, EDA) into the C–H bonds of methane, in a homogeneous process that uses supercritical carbon dioxide (scCO2) as the reaction medium. Other light alkanes such as ethane, propane, and butane have been also functionalized with this copper-based catalyst, in the first example of the derivatization of the series of C1–C4 alkanes with this metal and a soluble catalyst.

The first example of a diazo palladium adduct is reported. The complexes [(ArNHC−PPh)M(η-NC(Ph)COEt)] (M=Ni, 3; M=Pd, 4; ArNHC−PPh=3-(2,6-diisopropylphenyl)-1-[(diphenylphosphino)ethyl]imidazol-2-ylidene) were prepared by ligand exchange with styrene-coordinated precursors [(ArNHC−PPh)M(styrene)] (M=Ni, 1; M=Pd, 2). Complex 4 was fully characterized, including X-ray analyses; this constitutes the first example of a diazo adduct compound with palladium, thereby closing the gap between Groups 8 and 10 regarding this type of compounds., The authors wish to thank MINECO for financial support (CTQ2014‐52769‐C03‐01 and CTQ2011‐24502). S. G. R. thanks MINECO for a FPI fellowship.

Two families of nickel complexes bearing chelating diphenylphosphine-functionalized NHC ligands [NiII(ArNHCPPh2)(allyl)]Cl 1a (Ar = Mes); 1b, (Ar = 2,6-iPr2-C6H3) and [Ni0(ArNHCPPh2)(alkene)] 2a (Ar = 2,6-iPr2-C6H3, alkene = styrene); 2b (Ar = 2,6-iPr2-C6H3, alkene = diethyl fumarate) have been prepared and fully characterized. VT-NMR experiments in solution reveal that the allyl derivatives 1a–b are stereochemically nonrigid. The solid-state structure of the Ni0 derivative 2b is also reported. These complexes display interesting catalytic properties in various cross-coupling reactions. The precatalyst [Ni0(ArNHCPPh2)(styrene)] 2a was found to be the most active system. The bulkiness of the N-substituent on the imidazole ring and the low oxidation state of the metal center in 2a accounted for its enhanced catalytic performance. This system catalyzed effectively the coupling of (hetero)aryl chlorides with a range of nucleophiles including Grignard reagents, boronic acids, secondary amines and indoles.

International audience; The reaction of esters with ethyl diazoacetate catalyzed by the complex [F-27-Tp(4 Bo, 3CF2CF3)Ag(acetone)] generates alpha-(acyloxy)acetates in moderate to high yields. This is a novel transformation in the context of carbene-transfer reactions from diazo compounds that, according to experimental and theoretical data, is suggested to occur through zwitterionic intermediates.

The phototransformation of benzimidazole (BZ) and of the benzimidazole pesticide thiabendazole (TBZ) was investigated in aqueous solution in the absence and presence of the supramolecular host cucurbit[8]uril (CB8). ESI-MS and NMR reveal that both compounds form stable 1 : 2 host-guest complexes with CB8 (BZ2@CB8, TBZ2@CB8). The phototransformation of free BZ leads to dehydrodimerization, while for TBZ the photoreactivity leads to BZ, benzimidazole-2-carboximide and 2-acetylbenzimidazole. Inside CB8, BZ undergoes photohydrolysis to form 2-aminoformanilide, while for TBZ2@CB8 additional photoproducts were observed which are pH dependent. At pH 1.2 photolysis of TBZ2@CB8 leads to new red-shifted photoproducts with extended π conjugation.

The first example of a diazo palladium adduct is reported. The complexes [(ArNHC-PPh

The Pd0 complexes [(NHC)PdLn] (NHC=N-heterocyclic carbene ligand; L=styrene for n=2 or PR3 for n=1) efficiently catalyse olefin cyclopropanation by using ethyl diazoacetate (EDA) as the carbene source with activities that improve on previously described catalytic systems based on this metal. Mechanistic studies have shown that all of these catalyst precursors deliver the same catalytic species in solution, that is, [(IPr)Pd(sty)], a 14e- unsaturated intermediate that further reacts with EDA to afford [(IPr)Pd(=CHCO2Et)(sty)], from which the cyclopropane is formed. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim., We thank Prof. P. J. Pérez (Univ. Huelva) for helpful and constructive comments on these studies. We thank the Ministerio de Ciencia e Innovación (grants CTQ2008–00042BQU and CTQ2011–24502) and the Junta de Andalucía (Proyecto P07-FQM-02794) for financial support. CM thanks the MEC for a research fellowship

Copper homoscorpionate complexes TpxCu(I)(NCMe) efficiently catalyze the Atom Transfer Radical Polymerization (ATRP) of methacrylate (MMA) and other methacrylates at 50 °C in the absence of any red...

A series of complexes of general formulae Tp x Cu have been employed as the catalyst for the styrene cyclopropanation reaction with ethyl diazoacetate, both under homogeneous and heterogeneous conditions. Several solid supports have been tested, with silica gel being the most convenient for this transformation. A comparison of the results obtained under both conditions has shown that the catalytic pocket is affected by the support.

Thermal reactions between [RuCl2(diene)]n (diene = 2,5-norbornadiene, nbd; 1,5-cyclooctadiene, cod) with an excess of N,N,N',N'-tetramethylethylene diamine (tmeda) afforded derivatives [RuCl2(diene)(tmeda)] (diene = nbd, 1; cod, 2) as a mixture of cis and trans isomers. When thermolysis was performed under H2 mixtures of hydride species [RuCl(H)(diene)(tmeda)] (diene = nbd, 3; cod, 4) and the bis-tmeda adduct trans-[RuCl2(tmeda)2] (5) were obtained in different ratios depending upon the reaction conditions and reaction times. Heating polymeric Ru(II) precursors in toluene in the presence of a 5-fold excess of the bulkier N,N,N',N'-tetraethylethylene diamine (teeda) resulted in a rare diamine dealkylation process with formation of trans-[RuCl2(nbd)(Et2NCH2CH2NHEt)] (6) and trans-[RuCl2(cod)(EtHNCH2CH2NHEt)] (7) in high yields. The presence of N-H functionalities in the coordinated diamine ligands of 6 and 7 was unambiguously established by single-crystal X-ray diffraction studies. The dealkylation process of the teeda ligand seems to proceed intramolecularly as shown by solution NMR studies performed with the soluble Ru(II) precursors trans-[RuCl2(amine)2(diene)] (diene = nbd, amine = morpholine, 9; diene = cod, amine = Et2NH, 10). The above complexes [RuCl2(diene)(diamine)] have been tested as precatalysts in the hydrogenation of ketones both for transfer as well as direct hydrogenation, the latter route being the most effective.

A study of the variables that affect the insertion of the :CHCO2Et group (formed from ethyl diazocetate, EDA) into the C–H bonds of cyclohexane in the presence of a TpxCu complex as the catalyst (Tpx = trispyrazolylborate ligand) has demonstrated an anomalous effect of the catalyst loading. The use of low concentrations of catalyst produces an increase in the yield of the C–H activation product ethyl cyclohexaneacetate. This effect has also been found in the case of other less elaborated catalysts such as [BpBr3Cu] or [(bipy)2Cu][I]. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Cu(I) complexes containing trispyrazolylborate ligands efficiently catalyze the atom transfer radical addition (ATRA) of polyhalogenated alkanes to various olefins under mild conditions. The catalytic activity is enhanced when bulky and electron donating Tpx ligands are employed. Kinetic data have allowed the proposal of a mechanistic interpretation that includes a Cu(II) pentacoordinated species that regulates the catalytic cycle.

The complexes [TpBr3Ag]2·CH3COCH3 (1) and TpBr3Ag(thf) (2) catalyze the insertion of the :CHCO2Et group from ethyl diazoacetate (EDA) into the saturated C−H bonds of several C5, C6, and C8 linear and branched alkanes. In addition to secondary and/or tertiary sites, the unprecedented insertion into the primary C−H bonds of the substrates studied has been observed with variable regioselectivity, toward the methyl groups, within the range of 40−60% for branched and nearly 25% for linear alkanes.

The new complex Tp B r 3 Ir(C 2 H 4 ) 2 , 1, photochemically activates the C-H bonds of n-pentane in a two-step process, the first one being the formation of an isolable alkyl-hydride intermediate of composition Tp B r 3 Ir(H)(C 2 H 4 )(C 5 H 1 1 ), 3a, that subsequently undergoes β-hydride elimination to generate a terminal olefin complex, Tp B r 3 Ir(H) 2 (C 5 H 1 0 ), 4a. The reaction can also be extended to diethyl ether. In this case, the reaction proceeds by the activation of one of the β-C-H bonds (with respect to the O-ether atom) with formation of the alkyl-hydride 3b and the dehydrogenation product 4b. These processes also compete with the intramolecular C-H activation of one of the coordinated ethylene ligand by the Ir(I) center in 1, which affords the hydride-vinyl complex TpBr3Ir(H)(CH=CH 2 )(C 2 H 4 ), 2. Attempts to thermally induce the above transformations has led to the exclusive formation of a mixture of the hydride-α,ω-butenyl complex Tp B r 3 Ir(H)(CH 2 CH 2 CH=CH 2 ), 5, and the hydride-crotyl complex Tp B r 3 Ir(H)(C 4 H 7 ), 6.

Complexes of general formula TpxCu (Tpx = homoscorpionate ligand) have been employed as catalysts for the insertion of ethyl diazoacetate into C−H bonds of a variety of hydrocarbons and ethers, in moderate to high yields: tertiary, secondary, and primary C−H bonds have been functionalized by this methodology. Particularly interesting is the homologation of O-methyl groups in ethers, which has been achieved for a group of substrates. The existence of electron-withdrawing groups in the Tpx ligand seems to be crucial for the activity and the selectivity of the catalyst.

The complexes TpXCu (TpX = homoscorpionate ligands) efficiently catalyze the insertion of the carbene fragment :CHCO2Et, generated from ethyl diazoacetate, into the OH bond of saturated and unsatur...

A novel carbene transfer reaction from diazoesters to carboxylic acids is developed using a highly fluorinated tris(indazolyl)borate silver complex as catalyst.

International audience; Copper–carbene [TpxCu=C(Ph)(CO2Et)] and copper–diazo adducts [TpxCuη1-N2C(Ph)(CO2Et)] have been detected and characterized in the context of the catalytic functionalization of O–H bonds through carbene insertion by using N2=C(Ph)(CO2Et) as the carbene source. These are the first examples of these type of complexes in which the copper center bears a tridentate ligand and displays a tetrahedral geometry. The relevance of these complexes in the catalytic cycle has been assessed by NMR spectroscopy, and kinetic studies have demonstrated that the N-bound diazo adduct is a dormant species and is not en route to the formation of the copper–carbene intermediate.

Homoscorpionate ligands, with organic sulfides as cocatalyst, promote the reaction of phenyldiazomethane (II) with aldehydes (I) to form epoxides (III), with activities exceeding or, at least similar to those of reported rhodium-based systems.

Fe, Co, and Ni complexes of bulky Bp‘ ligands that contain two M···H−B three-center, two-electron interactions have been prepared and structurally characterized.

A series of ester-carbene complexes was synthesized. These complexes were found to be highly active for the metathesis of olefinic substrates, including acrylates and trisubstituted olefins. In addition, the ester-carbene moiety is thermodynamically high in energy. As a result, these complexes react to ring-open cyclohexene by metathesis to alleviate the thermodynamic strain of the ester-carbene ligand.

The fixation of the preformed polypyrazolylborate copper(I) complexes BpCu (1), Tp*Cu (2), and [B(pz)4]Cu (3) (Bp = dihydrobispyrazolylborate, H2B(pz)2; Tp* = hydrotris(3,5-dimethyl)pyrazolylborate, HB(pz*)3; B(pz)4 = tetrakispyrazolylborate) on silica gel and their use, under heterogeneous conditions, as catalysts for the olefin cyclopropanation reaction are reported. The catalytic activity is very similar to that observed under homogeneous conditions, as a consequence, according to the studies presented herein, of a ligand-to-support interaction that would involve the hydroxyl groups of the silica surface and the borohydride B−H group and/or the pyrazolyl nitrogen atoms. The strength of such interactions allows the recovery and recycling of the supported catalysts for a number of cycles.

Kinetic studies of the ethyl diazoacetate (EDA) decomposition reaction in the presence of BpCu (1) and in the presence or absence of olefin have led to the determination of several kinetic and thermodynamic parameters, and a consistent mechanism has been proposed for the olefin cyclopropanation reaction. Related studies with the complexes [Cu(bipy)2]I (bipy = bipyridine) and [Cu(bis(oxazoline))2]OTf have shown strong similarities with the results obtained with 1. A general mechanism covering the copper-based systems reported in the literature has been proposed, the real catalyst (i.e., the species to be reacted with EDA) in all cases being a neutral, 14-electron fragment of composition (L−L)Cu (L−L = Bp- and Tp-like ligands, semicorrins, salicylaldehyde derivatives) or, alternatively, the isoelectronic, cationic [(L−L)Cu]+ (for L−L = bis(oxazoline), bipyridine).

The stepwise, low-temperature reaction of {Pd[CH(SiMe3)2](μ-Cl)(PMe3)}2 (1) with CNBu-t and NaCp‘ (Cp‘ = C5H5, C5H4Me) or LiInd (Ind = C9H7) affords metal-substituted fulvenes of composition Pd[C(NHBu-t)C(C4H3R)][CH(SiMe3)2](CNBu-t)(PMe3) (R = H, Me) and Pd[C(NHBu-t)C(C8H6)][CH(SiMe3)2](CNBu-t)(PMe3), of which the C5H4Me-derived complex 5a has been characterized by X-ray crystallography. The mononuclear species Pd[CH(SiMe3)2]Cl(CNBu-t)(PMe3) (2) has been isolated as an intermediate of this reaction. An alternative synthesis of the palladabenzofulvene complex 6 involves the reaction of the 16 electron indenyl derivative (η3-Ind)Pd[CH(SiMe3)2](PMe3) (7) with 2 equiv of CNBu-t. In this case an η1-indenyl intermediate of composition (η1-Ind)Pd[CH(SiMe3)2](CNBu-t)(PMe3) (8) can be observed by low-temperature NMR spectroscopy. The complex Pt[CH(SiMe3)2]Cl(CNBu-t)(PMe3) (12) has been synthesized by the comproportionation reaction of Pt[CH(SiMe3)2]Cl(PMe3)2 (10) and Pt[CH(SiMe3)2]Cl(CNBu-t)2 (11), in the presence...

Regioselective methods for allene hydrosilylation have been developed, with regioselectivity being governed primarily by the choice of metal. Alkenylsilanes are produced via nickel catalysis with larger N-heterocyclic carbene (NHC) ligands, and allylsilanes are produced via palladium catalysis with smaller NHC ligands. These complementary methods allow either regioisomeric product to be obtained with exceptional regiocontrol.

(R)-Phenylglycinol is shown to be an efficient building block for the synthesis of chiral amino diols in pure diastereomeric form by epoxide ring-opening reactions. The reaction with rac-trans-stilbene oxide gives [HOCH(2)-(R)-PhCH]NH[(S)-PhCH-(R)-PhCHOH] [2(R)-3(R)-4(S)-HNO(2)H(2)] in 32% yield, which can be methylated at nitrogen to give enantiomerically pure [HOCH(2)-(R)-PhCH]NCH(3)[(S)-PhCH-(R)-PhCHOH] [2(R)-3(R)-4(S)-MeNO(2)H(2)]. These amino diol ligands have been used to prepare chiral dioxomolybdenyl complexes of the formula N(R)-2(R)-3(R)-4(S)-(HNO(2))MoO(2) (1) and N(R)-2(R)-3(R)-4(S)-(MeNO(2))MoO(2) (2). The absolute configuration at each stereocenter in the Mo(VI) complexes has been established by (1)H NOESY spectroscopy. The configuration determined for 1 has been confirmed by an X-ray analysis. Crystal data: orthorhombic P2(1)2(1)2(1), a =7.620(3), b = 13.589(2), c = 20.339(3) Å, Z = 4, R = 0.0336. The structure consists of a polymeric chain of N(R)-2(R)-3(R)-4(S)-(HNO(2))MoO(2) molecules connected through unsymmetrical Mo=O --Mo bridges. Each metal center is coordinated in a distorted octahedral geometry by a cis dioxo unit and by two trans alkoxo atoms. The coordination polyhedron is completed by a nitrogen atom and by a bridging oxo oxygen atom from an adjacent molecule. Compound 2 catalyzes the oxidation of PPh(3) to OPPh(3) by DMSO through a mechanism that involves the intermediacy of a Mo(IV) species.

Epoxides have been obtained from alde-hydes and phenyldiazomethane using catalytic amounts of both the copper homoscorpionate com-plexes Tp xCuL (Tpx = homoscorpionate ligand; L = acetonitrile or tetrahydrofuran, THF) and dimethyl sulfide (SMe2) in high yields and diasteroselectivities, and with activities higher (TOF = 46 h-1) than those already known with rhodium-or copper-based cata-lysts. Among the copper(I) homoscorpionate com-plexes tested, TpBr3Cu(NCCH 3) showed the highest catalytic activity under mild conditions. The catalytic activity is controlled by electronic effects induced by the Tp x ligand as well as by the stability of the TpxCu(SR 2) adducts. Indeed, in the case of TpMs as ligand, the TpMsCu(THT) (THT = tetrahydrothio-phene) and Tp MsCu(SMe2) species could be isolated as very stable crystalline solids, the molecular struc-ture of the former being confirmed by single-crystal X-ray diffraction analysis. The in situ generation of PhCHN 2 from benzaldehyde tosylhydrazone sodium salt at 60 °C in methyl tert-butyl ether as solvent and TpMsCu(THF) as the catalyst also showed high cata-lytic activities, improving those already reported with copper-based catalysts. © 2013 Wiley-VCH Verlag GmbH&Co. KGaA, Weinheim.

A set of barium aryl oxides of composition [Ba(OC6H2But2-2,6-X-4)2(thf)n](X = H 1, Me 2, OMe 3 or But4; thf = tetrahydrofuran) has been prepared together with the related adducts [Ba(OC6H2But2-2,6-X-4)2{P(NMe2)3O}2](X = H 5 or Me 6), which can be obtained by treating compounds 1 and 2 with neat P(NMe2)3O respectively. X-Ray studies showed that 6 has a distorted-tetrahedral structure, with the two Ba–O bonds to the aryl oxide ligands somewhat shorter than those to the P(NMe2)3O groups [2.414(8)vs. 2.579(8)A]. Samples of complex 4 and [Ti(OC6H3Pri2-2,6)4], respectively, and a third homogeneous sample obtained by mixing equimolar amounts of these have been subjected to bombardment by Ar+ and O2+ ions of relatively low energy (3.5 keV) and the ensuing transformation investigated by X-ray photoelectron spectroscopy. No significant variation of the C/M ratio was observed when employing Ar+ ions, but O2+ produced a remarkable decrease in the carbon content which leads eventually to the formation of inorganic compounds, BaCO3, TiO2 and BaTiO3, respectively, for the three samples. Action of oxygen plasma on the titanium aryl oxide did not result in a marked decrease in the C/M ratio, but it produced instead high concentrations of carbon- and oxygen-containing species.

The alkylation of [NiCl 2 (PMe 3 ) 2 ] with Mg[CH(SiMe 3 ) 2 ]Cl yielded the alkyl dimer [Ni{CH(SiMe 3 ) 2 }(μ-Cl)(PMe 3 )] 2 ( 1 ), which readily inserted CNBu t to afford [Ni{ η 2 -C(NBu t )CH(SiMe 3 ) 2 }Cl(PMe 3 )] ( 4 ); spectroscopic and X-ray studies reveal this complex contains an η 2 -alkaneimidoyl ligand.

The complexes TpBr3Cu(NCMe) (1) and TpMsCu (2) catalyze the addition of the :CHCO2Et unit (generated from N2CHCO2Et, EDA) to benzene to give a cycloheptatriene ring, in analogy with the Buchner reaction. When alkyl groups are attached to the aromatic rings, the selectivity of the reaction can be oriented toward addition or, alternatively, to the insertion into an alkyl C−H bond by using 1 or 2, respectively.

[EN] A novel bis-styrene IPrNi0 derivative has been synthesized from the reaction of Ni(COD)2 and free 1,3-bis(2,6-diisopropylphenyl)imidazolidene (IPr) ligand in the presence of styrene. The complex has been characterized by spectroscopic data as well as by X-ray crystallography. Its catalytic performance in the amination reaction of aryl tosylates is also reported. The catalytic reactions proceed in a very selective manner, affording moderate to high yields of cross-coupling products in short reaction times at 110 °C., This research was financially supported by the MINECO (Proyecto CTQ2011-24502 and Consolider Ingenio 2010, Grant No. CSD2006-003) and the Junta de Andalucia (Proyecto P07-FQM-02745). M.J.I. thanks the Junta de Andalucia for a research fellowship.

In this paper an ion beam induced chemical vapor deposition procedure is proposed for the preparation of oxide films. The method consists of the bombardment of a substrate with O+2 ions while a flow of a volatile precursor is directed onto it. The possibilities of the method are illustrated by a TiO2 thin film grown on quartz from Ti(CH3CH2O)4 as precursor. The grown film is studied by X-ray photoelectron spectroscopy, scanning and transmission electron microscopies, and UV-visible spectroscopy. The refractive indexes of the films (between 2.3 and 2.7) are similar to those of other TiO2 thin films prepared by ion beam assisted deposition methods.

Transition-metal-catalyzed atom transfer radical reactions of halogenated compounds with olefins constitute a versatile tool in organic synthesis within the area of C–C bond forming transformations. The inter- or intramolecular versions, atom transfer radical addition (ATRA) or cyclization (ATRC), respectively, lead to the atom-economic, useful synthesis of compounds that can be further functionalized. This contribution summarizes the recent developments in this area in terms of catalyst design as well as the applicability of this methodology in sequential, domino, or tandem reactions.

Experimental as well as theoretical studies have been carried out with the aim of elucidating the mechanism of the atom transfer radical addition (ATRA) of styrene and carbon tetrachloride with a TpxCu(NCMe) complex as the catalyst precursor (Tpx = hydrotrispyrazolyl−borate ligand). The studies shown herein demonstrate the effect of different variables in the kinetic behavior. A mechanistic proposal consistent with theoretical and experimental data is presented., We thank the MICINN (Grants CTQ2008-00042BQU, CTQ2008-06866-CO2-02/BQU, and Consolider Ingenio 2010 CSD2006-0003) and the Junta de Andalucía (Proyecto P07-FQM-02794) for financial support.

Transition-metal-catalyzed atom transfer radical reactions of halogenated compounds with olefins constitute a versatile tool in organic synthesis within the area of C–C bond forming transformations. The inter- or intramolecular versions, atom transfer radical addition (ATRA) or cyclization (ATRC), respectively, lead to the atom-economic, useful synthesis of compounds that can be further functionalized. This contribution summarizes the recent developments in this area in terms of catalyst design as well as the applicability of this methodology in sequential, domino, or tandem reactions., We thank the Ministerio de Ciencia e Innovacion (grants CTQ2008-00042BQU and CTQ2008-06866-CO2-02/BQU), Consolider Ingenio 2010 (CSD2006-0003), and the Junta de Andalucia (Grant P07-FQM-02794) for financial support.