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...

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

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

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 demonstrated to exercise full regio- chemoselectivity control, which opens new synthetic avenues nitrogenated heterocycles with predictable ring sizes. For first time, a uniform manifold has been identified for construction both pyrrolidine piperidine cores. individual steps this copper oxidation were elucidated by...

A procedure for generating the ruthenium hydride complex Ru(H)(H2)Cl(PCy3)2 in 95% yield is presented. Following a novel insertion−elimination pathway, this can react with propargyl or vinyl halides to make metathesis-active and alkyl carbene species general formulas (PCy3)2Cl2RuCH−CHCR2 (PCy3)2Cl2RuCHR, respectively. Tertiary chlorides work best, giving Ru−vinyl carbenes extremely high yield.

The complex TpBr3Cu(NCMe) catalyzes, at room temperature, the insertion of a nitrene group from PhINTs into carbon-hydrogen bond cyclohexane and benzene, as well primary C-H bonds methyl groups toluene mesitylene, in moderate to high yield.

A series of catalysts general formula TpXCu (TpX = homoscorpionate ligand) promote the insertion :CHCO2Et (ethyl diazoacetate as carbene source) into C-H bonds cycloalkanes and cyclic ethers in moderate to high yield. correlation between steric hindrance these yield transformation has been observed.

The synthesis of ruthenium carbenes by the reaction a Ru(0) compound or precursors with dihalo compounds is reported. A new procedure for preparation [Ru(H)2(H2)2(PCy3)2] and use this complex as starting material are presented.

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.

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 CHCO2Et group (from ethyl diazoacetate N2CHCO2Et, EDA) into C–H bonds methane, in a homogeneous process that uses supercritical carbon dioxide (scCO2) as reaction medium. Other light alkanes such ethane, propane, and butane have been also functionalized with this copper-based catalyst, first example derivatization series C1–C4 metal soluble catalyst.

Nickel catalysis is gaining in popularity recent years, mostly within the area of cross-coupling. However, unlike Pd, mechanisms Ni-catalyzed C–C and C–heteroatom bond forming reactions have been much less studied, particular when N-heterocyclic carbenes are used as ligands. Here, we present a thorough study mechanism C–N cross-coupling catalyzed by an NHC-Ni complex. Focusing on coupling 2-chloropyridines with indole [(IPrNi(styrene)2] (IPr =...

The complex Tp(Br3)Cu(NCMe) (1) is an excellent catalyst for the regioselective carbene transfer reaction to tertiary C-H bonds of hydrocarbons, at room temperature, using readily available ethyl diazoacetate (EDA) as source.

The complex IPrCuCl (1) catalyzes the transfer of :CHCO2Et group from ethyl diazoacetate (EDA) to unsaturated and saturated substrates (olefins, amine, alcohols) with very high yields. In absence substrate, 1 does not react EDA give diazo coupling products (fumarate maleate), a rare example in field metal-catalyzed diazocompounds decomposition.

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

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 presence styrene. The complex characterized by spectroscopic data as well X-ray crystallography. Its catalytic performance amination aryl tosylates is also reported. reactions proceed a very selective manner, affording moderate to high yields cross-coupling products short times at 110 °C.

Copper-carbene [Tp(x)Cu=C(Ph)(CO2Et)] and copper-diazo adducts [Tp(x)Cu{η(1)-N2C(Ph)(CO2Et)}] have been detected characterized in the context of catalytic functionalization O-H bonds through carbene insertion by using N2=C(Ph)(CO2Et) as source. These are first examples these type complexes which copper center bears a tridentate ligand displays tetrahedral geometry. The relevance cycle has assessed NMR spectroscopy, kinetic studies demonstrated that N-bound diazo adduct is dormant species not...

A series of complexes TpxCu (Tpx = homoscorpionate ligand) have been tested as the catalysts for olefin aziridination reaction using PhINTs nitrene source. Very high yields aziridines obtained with a group representative substrates, including nonactivated terminal olefins. The activity these has allowed use equimolar amounts and olefins, avoiding requirement excess olefin. In an effort to eliminate nondesired byproducts, chloramine-T employed source, in that produces sodium chloride sole...

In situ prepared copper catalysts Tp(X)Cu (Tp(X) = homoscorpionate) catalyze the olefin cyclopropanation reaction using ethyl diazoacetate as carbene source. Very high values of both activity and diastereoselectivity toward cis isomer have been obtained for styrene, alpha-methylstyrene, 1-hexene, 1-octene, vinyl acetate, n-butyl ether, 2,5-dimethyl-2,4-hexadiene, 3,3-dimethyl-1-butene. The effect temperature in was almost negligible within range -10 to +30 degrees C. Kinetic studies allowed...

The complexes TpXCu (TpX = homoscorpionate) catalyse the insertion of diazo compounds into nitrogen–hydrogen bonds amines and amides, under very mild conditions, with quantitative yields being obtained equimolar ratios reactants.

This contribution intends to highlight the use of metal-catalyzed functionalization unreactive carbon-hydrogen bonds by carbene insertion methodology, that employs diazo compounds as source.

Abstract A new and efficient nickel‐based protocol for the N ‐arylation of indoles carbazoles with aromatic chlorides, least expensive aryl halides, is described. The procedure provides selectively ‐(hetero)arylation products in good to high yields, short reaction times without adding an excess ligands. magnified image

The catalytic dechlorination of aryl chlorides performed by RuHCl(H2)2(PCy3)2 and RuH2(H2)2(PCy3)2 in alcohols is rapid complete within 1 h. mechanism involves a transfer hydrogenation step with participation the alcohol. system exhibits significant functional group tolerance. catalyst can be generated situ from [RuCl2(COD)]x (COD = cyclooctadiene) 2 equiv phosphine (PCy3 or PiPr3). Catalytic conversions are similar to those observed when an isolated precatalyst used. Mechanistic...

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

Abstract The reaction of carbon tetrachloride (CCl 4 ) with various 1,6‐heptadienes catalyzed by copper homoscorpionate complexes affords cyclization products in moderate to high yields. process involves the addition trichloromethyl radical diene followed a 5‐ exo‐trig reaction, resulting formation cis ‐3‐chloromethyl‐4‐(2,2,2‐trichloroethyl)cyclopentane isomers highly regiospecific and stereospecific manner. We have studied use magnesium (Mg) as reducing agent for regeneration copper(I)...