Andrea Biffis

• PhD
• Professor (Associate) at University of Padua

Low-dimensional nanomaterials with lattice confinement, including those of nanoclusters (NCs), offer benefits for fluorescence narrowing. Compared to quantum dots of metal NCs, however, one-dimensional structures of such NCs challenge the single-crystal synthesis. Here, we report the synthesis of a novel [Ag3(dppy)2(NO3)3]n cluster polymer through...

Chemical reduction of a dinuclear [(di‐NHC)Au2Cl2(di‐NHC)] complex (NHC=imidazol‐2‐ylidene), using excess NaBH4 as reducing agent in presence of dichloromethane (DCM) as solvent, provides a molecular cluster with formula [Au13(di‐NHC)5(CH3)2]Cl3, exhibiting covalent bonds between gold atoms of the cluster core and methyl groups. The presence of Au‐...

A catalytic system comprising a gold(I) complex with an N‐heterocyclic carbene (NHC) ligand in an ionic liquid as solvent exhibits higher catalytic efficiency compared to state of the art systems in the title reaction, which enables using down to 0.01 mol % gold. A commercial gold(I) catalyst such as IPrAuNTf2 can be employed for this purpose. In t...

N-methylation of amines is of great interest in the synthesis of pharmaceuticals and valuable compounds, and the possibility to perform this reaction with an inexpensive and non-toxic substrate like CO2...

Well‐defined (P,C)‐cyclometalated Au(III) complexes proved to be able to catalyze the synthesis of coumarins by intramolecular hydroarylation of a broad range of aryl propiolates under mild and practical conditions (0.1–2 mol% catalyst, 25–40 °C, 1–24 hours). The use of an ionic liquid as reaction solvent allowed to drastically decrease the amount...

Atomically precise nanoclusters hold promise for supramolecular assembly and (opto)electronic‐ as well as magnetic materials. Herein, this work reports that treating palladium(0) precursors with a triphosphirane affords strongly colored Pd8(PDip)6 that is fully characterized by mass spectrometry, heteronuclear and Cross‐Polarization Magic‐Angle Spi...

Dinuclear bisNHC (bis(N‐heterocyclic carbene)) gold(I) complexes 3 a and 4 a of general formula [Au2Br2(bisNHC)] were tested as catalysts in the cycloisomerization of N‐(prop‐2‐yn‐1‐yl)benzamide and in the hydromethoxylation of 3‐hexyne in the presence of silver(I) activators bearing different counteranions. The catalytic performance of mononuclear...

Palladium complexes with one N-heterocyclic carbene (NHC) and a pyridine ancillary ligand are powerful cross-coupling precatalysts. Herein, we report such complexes with a cyclic (alkyl)(amino)carbene (CAAC) ligand replacing the NHC. We find that the alleged reduced form, (CAAC)Pd(py), disproportionates to the (CAAC)2Pd0 complex and palladium nanop...

The factors determining the catalytic performance of a recently discovered system for direct intermolecular alkyne hydroarylations, comprising a gold(I) complex of general formula LAuX (L = neutral ligand; X = weakly coordinating counteranion) and an ionic liquid as solvent, have been investigated. In particular, the effect of the ionic liquid anio...

Herein, we report a new method to synthesize molecular gold nanoclusters (AuNCs) stabilized by phosphine (PR3) and di-N-heterocyclic carbene (di-NHC) ligands. The interaction of di-NHC gold(I) complexes, with the general formula [(di-NHC)Au2Cl2] with well-known [Au11(PPh3)8Cl2]Cl clusters provides three new classes of AuNCs through a controllable r...

A series of protic N‐heterocyclic carbene ligand precursors based on theophylline or adenine has been prepared, and the reactivity and coordination chemistry of these proligands towards iridium(III) centers has been investigated. Complex formation appears to be highly dependent on the proligand structure. In one case, a particularly stable complex...

The use of alkynyl gold(I) complexes covers different research fields, such as bioinorganic chemistry, catalysis, and material science, considering the luminescent properties of the complexes. Regarding this last application, we report here the synthesis of three novel dinuclear gold(I) complexes of the general formula [(diNHC)(Au-C≡CPh)2]: two Au-...

A library of platinum (II) complexes of general formula (O,O′-β-diketonate)PtLX (L = dimethylsulfoxide, pyridine, triphenylphosphine; X = chloride, γ-acetylacetonate) has been prepared, using synthetic methodologies available in the literature. The library has been supplemented with a novel platinum (II) complex bearing a triazenido N-oxide ligand....

The chapter covers the developments in the organometallic chemistry of silver(I) and silver(III) of the last 15 years. It is organized in sections dedicated to specific classes of ligands forming silver-carbon bonds, in particular alkyl and aryl ligands, N-heterocyclic carbene ligands and alkynyl ligands for silver(I), porphyrinoid ligands for silv...

A small library of dinuclear gold(I) complexes with the title ligands has been prepared, encompassing neutral, mono- and dicationic complexes. The luminescence properties of the complexes in the solid state have been evaluated, and it turns out that neutral and monocationic complexes not presenting a rigid metallamacrocyclic structure can exhibit r...

Two new gold(I) complexes with a di(N-heterocyclic carbene) ligand (diNHC) derived from caffeine have been synthesised by a base-assisted metalation of the appropriate di(azolium) salt in the presence of the gold precursor AuCl(SMe2). Under kinetically controlled conditions, the reaction affords a mononuclear cationic complex with the diNHC ligand...

Two novel gold(I) complexes with a phosphoguanidine ligand and with a novel cationic phosphane ligand have been prepared and structurally characterized. The phosphoguanidine ligand supports oxidative addition of biphenylene to the gold(I) centre, though the yield of the reaction is low. The phopshoguanidine gold(I) complexes is also able to efficie...

An overview of the current state of mechanistic understanding of gold-catalyzed intermolecular alkyne hydrofunctionalization reactions is presented. Moving from the analysis of the main features of the by-now-generally accepted reaction mechanism, studies and evidences pointing out the mechanistic peculiarities of these reactions using different nu...

The design of novel metal complexes with N-heterocyclic carbene (NHC) ligands that display biological activity is an active research field in organometallic chemistry. One of the possible approaches consists of the use of NHC ligands functionalized with a carbohydrate moiety. Two novel Au(I)–Au(I) dinuclear complexes were synthesized; they present...

The current state of the art of the use of cross‐linked organic polymers, both insoluble (resins or gels) and soluble (micro‐ and nanogels), as aids for the low‐temperature preparation of stable metal oxide nanoparticles or nanostructured metal oxides is reviewed herein. Synthetic strategies for inorganic oxide nanomaterials of this kind can greatl...

The current state of the art of the use of cross‐linked organic polymers, both insoluble (resins or gels) and soluble (micro‐ and nanogels), as aids for the low‐temperature preparation of stable metal oxide nanoparticles or nanostructured metal oxides is reviewed herein. Synthetic strategies for inorganic oxide nanomaterials of this kind can greatl...

The synthesis of novel iridium (III) complexes of general formula [IrClCp*(diNHC)](PF6), with chelating di (N-heterocyclic carbene) ligands (diNHC) is reported. The obtained complexes differ for the wingtip substituents at the nitrogen atom of the heterocycles (Me, t-Bu, Cy, n-oct), the linker between the carbene donors (-CH2-, –CH2CH2-, –CH2CH2CH2...

A series of six dinuclear gold(I) complexes with bridging bidentate N-heterocycic carbene ligands (NHCs) of general formula Au2Br2LX (L = diNHC, X = 1–6) have been studied as catalysts in the intermolecular hydroalkoxylation of terminal and internal alkynes. The best catalytic results have been obtained by using Au2Br2L4, characterized by 2,6-diiso...

N-phosphine oxide-substituted imidazolylidenes (POxIms) have been employed as heteroditopic ligands towards gold centres. Both bis-carbene and mono-carbene gold(I) complexes have been obtained, depending on the steric bulk of the employed POxIm ligand. Oxidation of the gold(I) complexes with halogens or halogen synthons allows access to both bis-ca...

A mild impregnation of graphene acid (GA) with Pd(OAc)2 yields Pd nanoparticles with a size that can be easily controlled by the amount of the Pd precursor, and with a sharp and tunable size distribution ranging from 1 nm up to 9 nm. The spectroscopic and microscopic characterization of the GA-Pd composites reveals a strong interaction between the...

Use of ionic liquids bearing the proper counteranion as reaction solvents allows to boost the reactivity of gold(I) complexes as catalysts in the hydroarylation of alkynes with arenes and heteroarenes. Several commercial complexes of general structure LAuX have been tested as catalysts, with L=1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene standi...

The catalytic potential of palladium(II) complexes with chelating N-phosphanyl-N-heterocyclic carbenes featuring a saturated imidazolin-2-ylidene or tetrahydropyrimid-2-ylidene ring has been investigated in intermolecular alkyne hydroamination reactions. The complexes were found to be among the most active Pd-based catalysts for these processes and...

We report on a single-step procedure for the synthesis of dinuclear gold(I) complexes with bridging di(N-heterocyclic carbene) (diNHC) ligands of general formula Au2Br2L¹⁻⁹ (L = diNHC). The obtained complexes differ in the bridging group between the carbene donors and in the terminal wingtip substituents at the imidazol-2-ylidene rings. The complex...

Cross-couplings and related reactions are a class of highly efficient synthetic protocols that are generally promoted by molecular Pd species as catalysts. However, catalysts based on more or less highly dispersed Pd metal have been also employed for this purpose, and their use, which was largely limited to the Heck reaction until the turn of the c...

A novel N-diadamantylphosphanyl-diaminocarbene 5 was prepared, isolated and characterised. The carbene appeared to be much more stable compared to previously reported di-tert-butyl congeners. The molecular structure of the carbene was determined by X-ray diffraction analysis. A novel (diisopropylamino)(diadamantylphosphanyl)carbene 8 was also prepa...

Two unprecedented, homoleptic Pt-1,8-naphthyridine complexes have been prepared and characterized. Reaction between 1,8-naphthyridine (napy) and a platinum(II) precursor leads to a mononuclear homoleptic platinum(II) complex with stoichiometry [Pt(napy)4](OTf)2. On the contrary, reaction between napy and a dinuclear platinum(III) precursor produces...

Unstabilized, pH-responsive soluble crosslinked polymers (microgels) bearing pendant trialkylamino or pyridyl groups and containing size-controlled Au or Pd nanoclusters have been prepared by radical copolymerization in dilute solution, followed by loading with HAuCl4 or Pd(OAc)2 and chemical reduction. The hydrodynamic volume, the solubility and t...

The use of transition metal complexes of non–heterocyclic N–donor ligands as olefin oligo/polymerization precatalysts is reviewed. These metal complexes with definite steric and electronic variations offer high catalytic activity resulting in the desired microstructure of the polymer products currently attracting significant attention by the cataly...

The application of metal–N-heterocyclic carbene (NHC) complexes as catalysts for the addition of water to multiple bonds in organic substrates is reviewed. Protocols for general and efficient reactions of this kind under mild conditions have been developed, in particular with gold–NHC complexes as catalysts for the hydration of alkynes, which have...

Silver(I) complexes bearing functionalized N-heterocyclic carbene (NHC) ligands have been comprehensively explored for their biological properties, but there are few reports on biological properties of this type of organometallics having heterocyclic O-functionalized NHCs. A series of sterically-tuned benzimidazolium hexafluorophosphate derivatives...

Neutral dinuclear gold(I) complexes having general formula [Au2Cl2(NHCP)] (NHCP = N-phosphanyl N-heterocyclic carbene) have been synthesised by two different synthetic procedures: i) transmetalation of the NHCP ligand from the corresponding dinuclear silver(I) complex; ii) deprotonation of the corresponding N-phosphanyl azolium/tetrahydropyrimidini...

We present herein a personal account of our achievements in the development of novel catalytic systems based on late‐transition‐metal complexes for the hydroarylation of alkynes. In particular, our targets were intermolecular hydroarylation reactions with arene or heteroarene substrates devoid of directing groups. We have shown that complexes of pa...

N-Phosphanyl-N-heterocyclic carbenes (NHCPs) featuring a saturated imidazolin-2-ylidene or tetrahydropyrimid-2-ylidene ring have been synthesized and characterized. The free carbenes exhibit good stability and can be stored in the solid state for months at ambient temperature without decomposition. Contrary to imidazoline-based NHCPs, which decompo...

The most significant recent developments in the chemistry of transition metal complexes with poly-N-heterocyclic carbene ligands (poly-NHCs) are reviewed herein. In particular, attention is focussed on the preparation of novel poly-NHCs, on their coordination chemistry toward transition metal centers, and on the applications of the resulting comple...

Novel dinuclear silver(I) and gold(I) complexes with 4,5-disubstituted diimidazol-2,2′-diylidene ligands featuring a methylene or 1,3-propylene bridge between the two N-heterocyclic carbene moieties were prepared and characterized. The substituents in the backbone of the heterocyclic ring are electron-withdrawing groups (chlorine atoms or cyanide g...

Complexes of palladium(II) with newly disclosed, N-phosphanyl acyclic diaminocarbene ligands are synthesized for the first time and structurally characterized. The ligands coordinate palladium(II) in a chelating fashion, yielding remarkably stable complexes which can be stored without special precautions in the solid state. Related palladium(II) co...

Diimidazolium salts featuring different bridges between the imidazolium groups, as well as electron-withdrawing groups (chloride, cyanide) at the 4- and 5-position of the heterocyclic rings, have been successfully prepared. The diimidazolium salts serve as convenient precursors of di(N-heterocyclic carbene) ligands, which coordinate in a chelating...

c Copper complexes with chiral iminopyridine ligands were screened for their catalytic efficiency in carbene (cyclopropanation) and nitrene transfer reactions (aziridination, C–H amidation). Both pre-formed and in situ formed complexes were considered. The results highlighted the poor catalytic efficiency of these complexes in cyclopropanation reac...

N-phosphorylated, N-heterocyclic carbenes (NHC) based on the imidazoline skeleton have been prepared for the first time. The free carbenes feature good stability and in best cases they can be stored in the solid state for months at ambient temperature without decomposition. The carbenes are capable of acting as ligands towards late transition metal...

Palladium(II) and platinum(II) complexes of the title ligands have been prepared; the two carbene moieties of the ligand coordinate to the metal in cis fashion, while the bridging pyridyl group remains outside the metal coordination sphere but close to the metal center. In this peculiar situation, the pyridyl group can assist the oxidation of the m...

Laponite nanoclay embedded inside soluble crosslinked copolymers (microgels) may act as cation exchanger allowing loading of the microgels with cationic metal precursors, which upon reduction yield tailored ternary colloidal nanocomposites comprising both nanoclay and metal nanoparticles. Microgel nanohybrids with variable Laponite nanoclay content...

Dinuclear silver(I) and gold(I) complexes with nonsymmetric macrocyclic dicarbene ligands featured by a 2,6-lutidinyl bridge as well as by a linker 3–4 carbon atoms long (1,3-propylene, o-xylylene, and 1,4-butylene) between two N-heterocyclic carbene groups have been prepared and structurally characterised. All complexes are formed as a mixture of...

A series of novel diisocyanide ligands (o-CNC6H4O)2Y (diNC-1: Y = P(O)Ph; diNC-2: Y = o-C(O)C6H4C(O); diNC-3: Y = m-C(O)C6H4C(O); diNC-4: Y = C(O)C2H4C(O); diNC-5: Y = trans-C(O)C2H2C(O)) was successfully synthesized by reaction of lithium 2-isocyanophenate (generated in situ from benzoxazole and n-BuLi) and a diacylic or phosphonic dichloride. The...

Copper species highly dispersed on suitable inert oxide supports catalyze the amidation of the α-CH bond of cyclic ethers using a com., environmentally benign nitrene source such as chloramine T. The catalytic efficiency depends on the nature of the support and of the dispersed copper species. The heterogeneous catalysts apparently operate by liber...

Four novel dinuclear N-heterocyclic dicarbene gold(i) complexes with a propylene linker between the carbene moieties have been synthesized and their luminescence and electrochemical properties, together with their reactivity towards bromine oxidative addition, have been screened. All the complexes emit in the solid state in the blue-green spectral...

Mono- and dinuclear gold complexes with N-heterocyclic carbene (NHC) ligands have been employed as catalysts in the intermolecular hydroarylation of alkynes with simple unfunctionalised arenes. Both mono- and dinuclear gold(III) complexes were able to catalyze the reaction; however, the best results were obtained with the mononuclear gold(I) comple...

Dinuclear silver(I) complexes with bridging N-phosphorylated azolylidene ligands have been synthesized. Subsequent transfer of the ligands to other group 11 metal centers (Cu, Au) has been accomplished, highlighting the usefulness of the silver complexes as an easy to handle, air- and moisture-stable source of these ligands. Preliminary results ind...

Monodisperse, molecularly imprinted nanospheres were synthesized by nonaqueous (mini)emulsion polymerization using a standard monomer mixture of methacrylic acid and ethylene dimethacrylate containing the drug propranolol as a template. The preparation conditions (solvent, amount of surfactant, and amount of employed template) were extensively vari...

Synthetic routes to novel N-phosphorylated 1,2,4-triazolium salts have been developed. Treatment of the specified salts with strong base produces new stable N-phosphorylated 1,2,4-triazol-5-ylidenes, which add Se in two stages (first at the carbene carbon and then at phosphorus) and rearrange to C-phosphorylated triazoles with heating. The capacity...

Oxidative addition of chlorine to dinuclear N-heterocyclic dicarbene gold(I) complexes of formula [Au2(RIm–Y–ImR)2](PF6)2 (R = Me, Y = (CH2)1–4; R = Cy, Y = CH2) affords in high yield stable Au(III)/Au(III) and Au(II)/Au(II) complexes. The nature of the products depends on the bridge between the two carbene moieties. With Y = methylene, ethylene an...

Di- and trinuclear complexes of copper(I) bearing bis- or tris-N-heterocyclic carbene ligands have been prepared and evaluated as catalysts in nitrene transfer reactions from PhI=NTs to unsaturated and saturated substrates (olefin aziridination and CH bond amidation) and carbene transfer reactions from diazo compounds to olefins. The complexes exhi...

Dinuclear N-heterocyclic dicarbene gold(I) complexes of general formula [Au(2)(RIm-Y-ImR)(2)](PF(6))(2) (R = Me, Cy; Y = (CH(2))(1-4), o-xylylene, m-xylylene) have been synthesized and screened for their luminescence properties. All the complexes are weakly emissive in solution whereas in the solid state some of them show significant luminescence i...

A series of dinuclear N-heterocyclic bis-dicarbene gold(III) complexes of the general formula [Au2Br4(RIm-Y-ImR)2](PF6)2 (Im = imidazol-2-ylidene; 1b, R = Me, Y = CH2; 2b, R = Me, Y = (CH2)2; 3b, R = Me, Y = (CH2)3; 4b, R = Me, Y = (CH2)4; 5b, R = Cy, Y = CH2; 6b, R = Me, Y = m-xylylene) were successfully synthesized by oxidative addition of bromin...

A dirhodium(II) complex with N-perfluorooctylsulfonylprolinate ligands is found to catalyze the cyclopropanation of olefins with simple aryl diazomethanes. In contrast to previously reported dirhodium(II) catalysts, the present complex works well not only with very electron-rich olefins such as enol ethers, but also with styrenes. Consequently, the...

The current state of the art in the development of methodologies for the preparation of MIPs in predetermined physical forms is critically reviewed, with particular attention being paid to the forms most widely employed in practical applications, such as spherical beads in the micro- to nanometer range, microgels, monoliths, membranes. Although app...

The preparation of nanosized, molecularly imprinted polymer particles by nonaqueous emulsion polymerization is presented. Monodisperse cross-linked polymer nanospheres with a diameter of around 100 nm were synthesized using a standard monomer mixture of methacrylic acid and ethylene dimethacrylate, containing (±)-propranolol as a template. The rebi...

A series of N-heterocyclic dicarbene palladium(II) complexes has been characterised combining different techniques (cyclic voltammetry, XPS and 13C NMR spectroscopy), in order to evaluate the influence of the dicarbene ligand on the electronic properties of the metal centre. The data obtained with the three techniques give relevant information, cyc...

A combination of chelating dicarbene—Pd(II) complex [PdBr2(BBIM)] with AgBF4 catalyzes the addition of various hetarenes towards phenylpropiolate (II).

The efficiency of dicarbene palladium(II) complexes and of simple palladium(II) acetate as catalysts for alkyne hydroarylation under liquid-liquid biphasic conditions involving an ionic liquid as the catalyst-containing phase is investigated. The results obtained under these conditions, both in terms of activity and selectivity, are compared with t...

A series of highly crosslinked microgels has been prepared at room temperature via photoinitiated polymerisation in dilute solution using methyl methacrylate (MMA) and ethylene dimethacrylate (EDMA), respectively as non-functional monomer and crosslinker in N,N-dimethylformamide (DMF) as a solvent. The effect of monomer concentration and EDMA/MMA r...

The tetracationic complex [Rh2(MeCN)2(Naft)4](BF4)4 (Naft=μ-1,8-naphthyridine) was found to be an efficient catalyst for the silylformylation of internal and functionalised alkynes to yield useful synthetic intermediates. The complex exhibits an unprecedented chemoselectivity towards alkyne silylformylation instead of simple hydrosilylation, as wel...

Palladium(II) complexes with chelating N-heterocyclic ligands bearing uncoordinated nitrogen atoms are efficient catalysts in the hydroarylation of alkynes, giving selectively trans-hydroarylation of the triple bond. The catalytic efficiency of these systems is markedly dependent on the strength of the acid added as reaction promoter, thus suggesti...

Chelating dicarbene complexes of palladium(II) and platinum(II) catalyse at room temperature with 1% catalyst loading the reaction of ethyl phenylpropiolate with aromatic heterocycles to yield synthetically useful intermediates for fine chemicals without the need to use prefunctionalized substrates. The reaction outcome was found to be strongly dep...

We demonstrate for the first time herein that electrospinning of soluble crosslinked polymer particles (microgels) is feasible and that it can be used to obtain micron-sized fibers from these macromolecules. Most notably, the electrospinning approach is found to be successful also in the case of microgels bearing metal nanoclusters, and allows to p...

Novel synthetic routes for the preparation of trinuclear copper(I) complexes with triscarbene ligands are presented, which yield higher purity products than the one previously described. The first crystal structure of one of these complexes is reported and confirms the expected structure. The trinuclear complexes proved to be efficient catalysts of...

Palladium(II) complexes with a ligand set made from a chelating N-heterocyclic dicarbene ligand and two weakly coordinating anions (generally introduced in situ upon addition of 2 equiv. of a suitable silver salt) were found to be very active and selective catalysts for the room-temperature hydroarylation of alkynes at low catalyst loading (0.1 mol...

Chelating dicarbene palladium(II) complexes have been found to catalyse the hydroarylation of alkynes with excellent conversions and selectivities at low catalyst loading (0.1 mol.%). Products of formal trans hydroarylation of the triple bond are formed in high yields. Optimisation of the reaction parameters (nature of the solvent system, concentra...

The reaction of diazo compounds with alkenes catalysed by complex [RuCl(cod)(Cp)] (cod = 1,5-cyclooctadiene, Cp = cyclopentadienyl) has been studied. The catalytic cycle involves in the first step the decomposition of the diazo derivative to afford the reactive [RuCl(Cp){=C(R(1))R(2)}] intermediate and a mechanism is proposed for this step based on...

New silver(I) carbene complexes were obtained starting from the N-heterocyclic carbene ligand precursors {[HB(RImH)3]Br2} (R=Bn, Mes and t-Bu) and {[HC(MeBImH)3](BF4)3}, by treatment of the imidazolium salt with Ag2O. Use of the tris-imidazolylborate precursors resulted in stable, well-characterized trimetallic complexes of general formula {Ag3[HB(...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A novel trinuclear copper(I) complex with a chelating tricarbene ligand is shown to be an efficient catalyst for the arylation of different classes of compounds containing N–H or O–H functions. Different kinds of azole rings (pyrazole, imidazole, 1,2,4-triazole) can be arylated with comparable efficiencies at relatively mild temperatures (100°C). T...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

1 We report on a novel reaction protocol for the coupling of arenes with alkynes (the Fujiwara reaction), yielding products of formal trans-hydroarylation of the triple bond. The protocol makes use of a chelating N-heterocyclic dicarbene palladium(II) complex as catalyst and allows us to perform the reaction in a few hours with only 0.1 mol % catal...

Copper(II) oxide and Cu metal, highly dispersed on inert oxides (silica, alumina), have been employed as precatalysts in ligand-free, palladium-free Sonogashira coupling reactions. Best results were obtained with highly dispersed Cu metal on alumina, which exhibited high reactivity with aryl iodides. Electron-rich alkynes, in particular arylacetyle...

A set of cationic dirhodium(II) complexes with oxo thioethers was prepared and employed as catalysts for the silane alcoholysis reaction. The complexes were found to be highly active under homogeneous conditions, both in the absence and in the presence of a solvent, including coordinating solvents such as N,N-dimethylformamide; the catalysts could...

Gold nanoclusters of small size (2.5 nm) and narrow size distribution were synthesized in solution using tailor-made soluble cross-linked polymers (microgels) as exotemplates and stabilizers. The resulting microgel-stabilized nanoclusters could be conveniently isolated by precipitation, stored in the solid state, and redispersed in water and polar...

The reaction of cyclopentadienyl ruthenium complexes of the type [RuCl(Cp)L1L2] (L1, L2 = PPh3, PMe2Ph, PMePh2; L1L2 = dppe; L1L2 = COD; L1 = CO, L2 = PPh3) with Licarb (Hcarb = 2-Me-1,2-dicarba-closo-dodecaborane) gives two types of complexes, [Ru(H)(C5H4-carb)L1L2] or [Ru(carb)(Cp)L1L2], depending on the nature of the coordination set. The struct...

The neutral dirhodium(II) acetate [Rh2(OAc)4] and the related cationic complex [Rh2(OAc)2(MeCN)6](BF4)2 react with 2-(trimethylsiloxymethyl)phenyl isocyanide (I) and/or 2-(hydroxymethyl)phenyl isocyanide (II) to give the corresponding adducts, in which the entering isocyanide occupies the axial position at the two rhodium centres. These complexes a...

The synthesis of cationic dirhodium(II) complexes by partial or total substitution of the acetate groups of [Rh2(OAc)4] with different homoleptic neutral bidentate ligands has been attempted. The ligand 1,8-naphthyridine gave the best results: substitution of one as well as of all four acetate ligands is possible, giving rise to mono-, di- and tetr...

The reactivity of copper(II) acetate as catalyst in a standard CO coupling reaction has been systematically evaluated. Optimization of the reaction conditions resulted in a protocol involving stoichiometric amounts of reagents, a substoichiometric amount of base and 20 mol% catalyst, at 50 °C in 1,2-dichloroethane and under 1 atm O2. Next, the reac...