Fernando J Lahoz

• Senior Researcher at Spanish National Research Council

The rhodium and iridium complexes [Cp*M(κ³N,N′,N″-L)][SbF6] (Cp* = η⁵-C5Me5; M = Rh, 1; Ir, 2; HL = pyridinyl-amidine ligand) exhibit three different cooperative metal–ligand reactivity modes when interacting with nonfunctionalized ketones. With the methyl ketones CH3COR (R = CH3, Ph, CF3), activation of the ketone methyl C(sp³)–H bond yields keton...

This work aims to amplify the fluorescence of (Z)-4-hetarylidene-5(4H)-oxazolones 1 by suppression of the hula-twist non-radiative deactivation pathway by C^N-orthopalladation of the 4-hetarylidene ring. Different (Z)-4-hetarylidene-2-phenyl-5(4H)-oxazolones, 1a–1c, prepared by the Erlenmeyer–Plöchl method, have been studied. The orthopalladation o...

Rh(III) and Ru(II) complexes, [RhCl2(κ⁴‐N2N'P‐L)][SbF6] (1) and [RuCl2(κ⁴‐N2N'P‐L)] (2), were synthesised using the tetradentate ligand L (L=N,N‐bis[(pyridin‐2‐yl)methyl]‐[2‐(diphenylphosphino)phenyl]methanamine). In each case only one diastereomer is detected, featuring cis‐disposed pyridine groups. The chloride ligand trans to pyridine can be sel...

The masked transition‐metal frustrated Lewis pairs [Cp*M(κ³N,N’,N’’‐L)][SbF6] (Cp*=η⁵‐C5Me5; M=Ir, 1, Rh, 2; HL=pyridinyl‐amidine ligand) reversibly activate H2 under mild conditions rendering the hydrido derivatives [Cp*MH(κ²N,N’‐HL)][SbF6] observed as a mixture of the E and Z isomers at the amidine C=N bond (M=Ir, 3Z, 3E; M=Rh, 4Z, 4E). DFT calcu...

The unique dynamic configuration of an enantioselective chiral‐at‐metal catalyst based on Rh(III) and a non‐chiral tetradentate ligand is described and resolved. At room temperature, the catalyst undergoes a dynamic configuration process leading to the formation of two interconvertible metal‐stereoisomers, remarkably without racemization. Density f...

The transition metal frustrated Lewis pair compounds [(Cym)M(κ3S,P,N-HL1)][SbF6] (Cym = η6-p-MeC6H4iPr; H2L1 = N-(p-tolyl)-N'-(2-diphenylphosphanoethyl)thiourea; M = Ru (5), Os (6)) have been prepared from the corresponding dimer [{(Cym)MCl}2(μ-Cl)2] and H2L1 by successive chloride abstraction with NaSbF6 and AgSbF6 and NH deprotonation with NaHCO3...

A new methodology for the preparation of Co(I)-NHC (NHC = N-heterocyclic carbene) complexes, namely, [Co(PCNHCP)(CO)2][Co(CO)4] (1) and [Co(PCNHCP)(CO)2]BF4 (2), has been developed (PCNHCP = 1,3-bis(2-(diphenylphosphanyl)ethyl)-imidazol-2-ylidene). Both complexes can be straightforwardly prepared by direct reaction of their parent imidazolium salts...

Neutral [X−{Ir2}−{Ir2}−X] (X=Cl, Br, SCN, I) and dicationic [L−{Ir2}−{Ir2}−L]²⁺ (L=MeCN, Me2CO) tetrametallic iridium chains made by connecting two dinuclear {Ir2} units ({Ir2}=[Ir2(μ‐OPy)2(CO)4], OPy=2‐pyridonate) by an iridium–iridium bond are described. The complexes exhibit fractional averaged oxidation states of +1.5 and electronic delocalizat...

Correction for 'Iridium-(κ2-NSi) catalyzed dehydrogenation of formic acid: effect of auxiliary ligands on the catalytic performance' by Alejandra Gomez-España et al., Dalton Trans., 2023, 52, 6722-6729, https://doi.org/10.1039/d3dt00744h.

Correction for 'Iridium-(κ2-NSi) catalyzed dehydrogenation of formic acid: effect of auxiliary ligands on the catalytic performance' by Alejandra Gomez-España et al., Dalton Trans., 2023, https://doi.org/10.1039/d3dt00744h.

The iridium(III) complexes [Ir(H)(Cl)(κ2-NSitBu2)(κ2-bipyMe2)] (2) and [Ir(H)(OTf)(κ2-NSitBu2)(κ2-bipyMe2)] (3) (NSitBu2 = {4-methylpyridine-2-yloxy}ditertbutylsilyl) have been synthesized and characterized including X-ray studies of 3. A comparative study of the catalytic activity of complexes 2, 3, [Ir(H)(OTf)(κ2-NSitBu2)(coe)] (4), and [Ir(H)(OT...

An improved synthesis of the racemic rhodium compound [RhCl2(κ4 C,N,N',P-L1)] (1) containing an achiral tripodal tetradentate ligand is reported. Their derived solvate complexes [Rh(κ4 C,N,N',P-L1)(Solv)2][SbF6]2 (Solv = NCMe, 2; H2O, 3) are resolved into their two enantiomers. Complexes 2 and 3 catalyze the Diels-Alder (DA) reaction between methac...

Reaction of the dimers [(Cp*MCl)2(μ-Cl)2] (Cp* = η5-C5Me5) with Ph2PCH2CH2NC(NH(p-Tolyl))2 (H2L) in the presence of NaSbF6 affords the chlorido complexes [Cp*MCl(κ2N,P-H2L)][SbF6] (M = Rh, 1; Ir, 2). Upon treatment with aqueous NaOH, solutions of 1 and 2 yield the corresponding complexes [Cp*M(κ3N,N',P-HL)][SbF6] (M = Rh, 3; Ir, 4) in which the lig...

In this contribution, we report the preparation of iron thiosulfonato complex CpFe(CO)2SSO2CH=CHPh (1) and its selenosulfonato analogue CpFe(CO)2SeSO2CH=CHPh (2) featuring styrene moiety. 1 and 2 are obtained by electrophilic attack of (μ-Ex)[CpFe(CO)2]2 (E = S; x = 2–4, E = Se; x = 1) on the sulfur atom of styrene sulfonyl chloride ClSO2CH=CHPh. T...

A series of neutral [RhX(nbd)(κC-MeIm∩Z)] and cationic [Rh(nbd)(κ ² C,N-MeIm∩Z)]+ (X = Cl, Br; MeIm = 3-methylimidazol-2-yliden-1-yl; ∩Z = N-functionalized wingtip; nbd = 2,5-norbornadiene) complexes featuring NHC ligands functionalized with a 1-aminopropyl,...

The dimer [{( η6‐p‐cymene)RuCl}2(μ‐Cl)2] (cymene = MeC6H4iPr) reacts with N,N’‐bis(p‐Tolyl)‐N’’‐(2‐pyridinylmethyl)guanidine (H L1) and N,N’‐bis(p‐Tolyl)‐ N’’‐(2‐diphenylphosphanoethyl)guanidine (H2L2), in the presence of NaSbF6, giving rise to chlorido compounds of formula [(η6‐p‐cymene)RuCl(H2L)][SbF6] (H2L = H2L1 (1), H2 L2 (2)) in which the gua...

Iridium(III) complexes of the general formula [Ir(X)(κ²-NSiiPr2)2] (NSiiPr2 = (4-methyl-pyridine-2-yloxy)diisopropylsilyl; X = Cl, 3; CF3SO3, 5; CF3CO2, 6) have been prepared and fully characterized, including X-ray diffraction studies and theoretical calculations. The presence of isopropyl substituents at the silicon atom favours the monomeric str...

The reaction of the rhodium aqua-complex (SRh,RC)-[Cp*Rh{(R)-Prophos} (OH2)][SbF6]2 [Cp* = C5Me5, Prophos = propane-1,2-diyl-bis(diphenylphosphane)] (1) with trans-4-methylthio-β-nitrostyrene (MTNS) gives two linkage isomers (SRh,RC)-[Cp*Rh{(R)-Prophos}(κ1O-MTNS)]2+ (3-O) and (SRh,RC)-[Cp*Rh{(R)-Prophos}(κ1S-MTNS)]2+ (3-S) in which the nitrostyrene...

Pyridinyl- and phosphano-guanidino complexes of formula [(η6-p-cymene)OsCl(H2L)][SbF6] (cymene = MeC6H4iPr; H2L = N,N'-bis(p-Tolyl)-N''-(2-pyridinylmethyl)guanidine, H2L1 (1) and N,N'-bis(p-Tolyl)-N''-(2-diphenylphosphanoethyl)guanidine, H2L2 (2)) have been prepared from the dimer [{(η6-p-cymene)OsCl}2(μ-Cl)2] and H2L in the presence of NaSbF6. Tre...

A series of Rh(κ²‐BHetA)(η²‐coe)(IPr) complexes bearing 1,3‐bis‐hetereoatomic acidato ligands (BHetA) including carboxylato (O,O), thioacetato (O,S), amidato (O,N), thioamidato (N,S), and amidinato (N,N), have been prepared by reaction of the dinuclear precursor [Rh(μ‐Cl)(IPr)(η²‐coe)]2 with the corresponding anionic BHetA species. The RhI‐NHC‐BHet...

The iridium complex [Ir(μ-CF3SO3)(κ²-NSiMe2)2]2 (3) (NSiMe2 = {4-methylpyridine-2-yloxy}dimethylsilyl) has been prepared by reaction of [Ir(μ-Cl)(κ²-NSiMe2)2]2 (1) with two equivalents of AgCF3SO3. The solid structure of 3 evidenced its dinuclear nature, being a rare example of an iridium species with triflate groups acting as bridges. The 3-cataly...

The dormant FLP complex [Cp*Rh(κ3N,N’,P‐L)][SbF6], based on a phosphano‐guanidine ligand, is an air‐ and moisture‐stable solid. Nevertheless, in solution it readily renders a coordinatively unsaturated derivative by means of a Rh−N bond dissociation. This dissociated intermediate behaves as a genuine FLP species and easily activates the H−O bond of...

And the beast wakes up! The dormant FLP complex (see scheme) can be isolated as an air‐ and moisture‐stable solid. But, in solution, the dissociated active FLP state is easily accessible and the complex activates H2O and H2, under soft conditions, in a reversible manner. Concurrently, a facile H/D exchange at the Cp* ligand, associated with water a...

The reaction of (4-methyl-pyridine-2-iloxy)dimethylsilane (NSiMe–H, 1) with [RhCl(coe)2]2 gives the rhodium(III) complex [Rh(Cl)(κ²-NSiMe)2] (2), which reacts with a stoichiometric amount of AgCF3CO2 to afford [Rh(κ²-CF3CO2)(κ²-NSiMe)2] (3). Complexes 2 and 3 have been fully characterized by elemental analysis and NMR spectroscopy. The solid-state...

The iridium(III) complex [Ir(CF3CO2)(κ2-NSi)2] (3) (NSi = 4-methylpyridine-2-yloxydimethylsilyl) has proven to be an effective catalyst for the reduction of CO2 with HSiMe(OSiMe3)2 under mild reaction conditions. 1H NMR studies of the 3-catalyzed reactions of CO2 with HSiMe(OSiMe3)2 in C6D6 at 298 K evidenced that the selectivity of these reduction...

Reaction of [Ir(μ-Cl)(COE)2]2 (COE = cis-cyclooctene) with tris(3,5-dimethylpyrazol-1-yl)methane (MeTpm) affords complex [IrCl(κ1-N-MeTpm)(COD)] (1) (COD = 1,5-cyclooctadiene). The formation of 1 implies the transfer dehydrogenation of a COE ligand to give COD and COA (cyclooctane). A mechanistic proposal based on DFT calculations that explains thi...

The reaction of (4-methyl-pyridin-2-iloxy)ditertbutylsilane (NSitBu-H, 1) with [IrCl(coe)2]2 affords the iridium(III) complex [Ir(H)(Cl)(κ2-NSitBu)(coe)] (2), which has been fully characterized including X-ray diffraction studies. The reaction of 2 with AgCF3SO3 leads to the formation of species [Ir(H)(CF3SO3)(κ2-NSitBu)(coe)] (3). The iridium comp...

Synthetic routes for ruthenium(II) complexes bearing the {Ru(κ⁴C,N,N′,P-L)} fragment (L = tripodal tetradentate ligand) are explored. Tripodal ligands LH1–LH3 diastereoselectively react with the dimer [{(Cy)RuCl}2(μ-Cl)2] (Cy = η⁶-p-MeC6H4iPr), affording the p-cymene compounds [(Cy)Ru(κ³N,N′,P-LH)][SbF6] (1–3). Refluxing complexes 1–3 in MeCN gives...

The pincer ligand HN(CH2CH2PPh2)2 (1; PNHP) reacted with [{Ir(μ-X)(cod)}2] (X = Cl, OMe), affording complexes [fac-(PNHP)Ir(cod)]Cl (2) and [fac-(PNP)Ir(cod)] (3), respectively. The X-ray molecular structure of 2 showed that the PNP ligand coordinates in a facial fashion, with the N atom in an axial site and both P atoms coordinated in the equatori...

A series of water-soluble zwitterionic rhodium and iridium complexes featuring a carboxylate bridge-functionalized bis-N-heterocyclic carbene ligands were synthesized. The uncoordinated carboxylate fragment is reactive toward electrophiles affording cationic complexes featuring carboxy and methoxycarbonyl functionalized ligands. In contrast, the ox...

The challenging control of the absolute configuration of chiral-at-metal complexes is efficiently achieved using the tripodal tetradentate ligand L. The optical resolution of rac-[RhCl2(κ4C,N,N’,P−L)] mediated by (S)-α-phenylglycine pro-vides access to enantiopure complexes of general formula [Rh(κ4C,N,N’,P−L)A(Solv)][SbF6]n that enantioselectively...

Reaction of the acetylacetonates [(η⁵-C5Me5)M(acac)Cl] with (SP)-[HMaxPhos][BF4] afforded cationic complexes of formula (SM,RP)-[(η⁵-C5Me5)MCl(MaxPhos)][BF4] (M = Rh (1), Ir (2)). Reaction of (SP)-MaxPhos with [RuCl(μ-Cl)(η⁶-p-MeC6H4ⁱPr)]2 and NH4X gave (SRu,RP)-[(η⁶-p-MeC6H4ⁱPr))RuCl(MaxPhos)][X] (X = BF4 (3), PF6 (3')). The complexes have been co...

This work describes the results from the studies on the potential of [Ir(-Cl)(cod)]2 (cod = 1,5-cyclooctadiene) as metallic precursor for the preparation of Ir(NSiN) complexes (NSiN = fac-bis-(pyridine-2-yloxy)methylsilyl). It is noteworthy that the reaction of [Ir(-Cl)(cod)]2 with bis-(pyridine-2-yloxy)methylsilane has allowed the synthesis of [...

Herein we report on the different chemical reactivity displayed by two mononuclear terminal amido compounds depending on the nature of the coordinated diene. Hence, treatment of amido-bridged iridium complexes [{Ir(-NH2)(tfbb)}3] (1; tfbb = tetrafluorobenzobarrelene) with dppp (dppp = bis(diphenylphosphane)propane) leads to the rupture of the amid...

Acetonitrile suspensions of the dichlorido complexes [MCl2(κ4C,N,N',P−L)] (M = Rh (1), Ir (2)) react with AgSbF6 in a 1/2 molar ratio affording the bis-acetonitrile complexes [M(κ4C,N,N',P−L)(NCMe)2][SbF6]2 (3, 4). The reaction takes place in a sequential manner and the intermediates can be isolated varying the M/Ag molar ratio. In a 2/1 molar rati...

The hydrosilylation of CO2 with different silanes such as HSiEt3, HSiMe2Ph, HSiMePh2, HSiMe(OSiMe3)2 and HSi(OSiMe3)3 in presence of catalytic ammounts of the iridium(III) complex [Ir(H)(CF3CO2)(NSiN*)(coe)] (1; NSiN* = fac-bis-(4-methylpyridine-2-yloxy); coe = cis-cyclooctene) has been comparatively studied. The activity of the hydrosilylation cat...

New RhI-IPr (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazolin-2-carbene) complexes bearing an N,O-pyridine-2-methanolato (N-O) bidentate ligand have been prepared. The carbonyl complex Rh(N-O)(IPr)(CO) efficiently catalyzes the hydrothiolation of a range of alkynes with high selectivity to α-vinyl sulfides. Reactivity studies and DFT calculations hav...

Ligands LH1-LH3 have been prepared by two successive condensation/reduction steps. These ligands react with MCl3 (M = Rh, Ir) rendering the trichlorido complexes [MCl3(κ3N,N’,P−LH)] (M = Rh, LH = LH1 (1), LH2 (2), LH3 (3); M = Ir, LH = LH1, (4)) as racemic mixtures of fac and mer isomers. Only one of the two possible fac isomers was detected. The m...

The dimers [{(η(n)-ring)MCl}2(μ-Cl)2] ((η(n)-ring)M = (η(5)-C5Me5)Ir, (η(6)-p-MeC6H4iPr)Ru) react with the modified cysteines S-benzyl-l-cysteine (HL1) or S-benzyl-α-methyl-l-cysteine (HL2) affording cationic complexes of the formula [(η(n)-ring)MCl(κ(2)N,S-HL)]Cl (1, 2) in good yield. Addition of NaHCO3 to complexes 1 and 2 gave equilibrium mixtur...

RhI–NHC–olefin complexes bearing a N,O-quinolinolate bidentate ligand have been prepared from [Rh(μ-OH)(NHC)(η2-olefin)]2 precursors (olefin = cyclooctene, ethylene). The disposition of the chelate ligand with regard to the carbene in the square planar derivatives is strongly influenced by the steric hindrance exerted by the coordinated olefin. The...

Treatment of acetone solutions of the known chlorido-bridged complexes [{M(m-Cl)(cod)}2] (M = Ir, Rh; cod = 1,5-cyclooctadiene) under an ammonia atmosphere afforded the cationic complexes [M(cod)(kN,kN-NH2-C(CH3)2-CH2-C(CH3)=NH)]Cl (M = Ir (3), Rh (4)). The molecular structures of 3 and 4 showed the formation of six-membered metallacycles due to th...

A series of rhodium–NSiN complexes (NSiN=bis (pyridine-2-yloxy)methylsilyl fac-coordinated) is reported, including the solid-state structures of [Rh(H)(Cl)(NSiN)(PCy3)] (Cy=cyclohexane) and [Rh(H)(CF3SO3)(NSiN)(coe)] (coe=cis-cyclooctene). The [Rh(H)(CF3SO3)(NSiN)(coe)]-catalyzed reaction of acetophenone with silanes performed in an open system was...

The modified cysteine ligand, S-benzyl-α-methyl-l-cysteine (HL2), was prepared from l-cysteine hydrochloride methyl ester. The reaction of commercial S-benzyl-l-cysteine (HL1) or HL2 with the dimer, [{(η(5)-C5Me5)RhCl}2(μ-Cl)2], gives rise to the cationic complexes, [(η(5)-C5Me5)RhCl(HL)]Cl (HL = HL1 (1), HL2 (2)), in which the cysteine ligand exhi...

By changing the temperature from 283 to 233 K, the S (99 % ee) or R (96 % ee) enantiomer of the Friedel-Crafts (FC) adduct of the reaction between N-methyl-2-methylindole and trans-β-nitrostyrene can be obtained by using (SRh ,RC )-[(η(5) -C5 Me5 )Rh{(R)-Prophos}(H2 O)][SbF6 ]2 as the catalyst precursor. This catalytic system presents two other unc...

The treatment of [(Ir(μ-Cl)(cod))2] (cod = 1,5-cyclooctadiene) with 2,5-norbornadiene (nbd) in the presence of triethylphosphane under an atmosphere of ammonia afforded the cation complex [Ir(κC,κC-C21H24)(NH3)3(PEt3)]Cl (1a) and complex [Ir(κC,κC-C21H24)Cl(NH3)2(PEt3)] (1b), the structures of which include a novel seven-membered iridacycle formed...

It has been demonstrated that the reaction of [2,2,2-(H)(PPh3)2-closo-2,1-RhSB8H8] () with PPh3 affords the boron substituted rhodathiaborane-PPh3 adduct, [6,6-(PPh3)2-9-(PPh3)-arachno-6,5-RhSB8H9] (). Building upon this reaction, we report herein that the 10-vertex hydridorhodathiaborane reacts with the Lewis bases, PCy3, py, 2-Mepy, 2-Etpy, 3-Mep...

The cationic half-sandwich aqua-complexes [(η5-C5Me5)M(PP∗)(H2O)][SbF6]2 [M = Rh, Ir; PP∗ = (R)-Benphos, (R)-Cyphos, (2R,4R)-Norphos] catalyse the 1,3-dipolar cycloaddition reaction of nitrones with methacrylonitrile with perfect regioselectivity, low-to-perfect endo-selectivity and low-to-moderate enantioselectivity. The active species involved in...

The chloro complex [IrCl(cod)(dppe)] (dppe = bis(diphenylphosphane)ethane; cod = 1,5-cyclooctadiene) was found to react with gaseous ammonia, affording the amido-bridged diiridium complex [{Ir(μ-NH2)H(dppe)(NH3)}2][Cl]2 (1), whose molecular structure has been solved by X-ray methods. The related cationic complexes [{Ir(μ-NH2)H(dppp)(NH3)}2][BF4]2 (...

The catalytic activity of various Ir-NSiN-type complexes, containing different ancillary ligands and/or modified NSiN-type ligands, as catalyst precursors for CO2-hydrosilylation has been studied. The results from these experiments evidenced that the activity and selectivity of the above mentioned catalytic systems depend on the nature of the ancil...

Treatment of heterobimetallic sulfido-bridged complexes [Cp(acac)Ti(μ3-S)2{M(cod)}2] (M = Rh (1), Ir (2)) with the organic acids CX3COOH (X = F, H) forms the corresponding acetate derivatives [Cp(CX3COO)Ti(μ3-S)2{M(cod)}2] (X = F, M = Rh (3), Ir (4); X = H, M = Rh (5), M = Ir (6)). While complex 3 was easily isolated, compounds 4-6 establish in sol...

Treatment of complex [Cp2TiCl2] with the lithium salt of 2-hydroxypyridine afforded complex [Cp2Ti(Opy)2] (1), whereas the same synthetic strategy applied to the analogous zirconium compound [Cp2ZrCl2] did not worked. However, the use of the metallocene [Cptt2ZrMe2] with protic ligands allowed directing the reactivity towards protonation of the met...

The copper(I) complexes [Cu(X){2,6-diisopropylphenyl–NHC–(CH2)3Si(OiPr)3}] (X=Cl (2 a); I (2 b), NHC=N-heterocyclic carbene) have been synthesized and characterized. Furthermore, the structure of 2 b has been confirmed by X-ray diffraction studies. Complex 2 a has been successfully anchored in MCM-41 to afford 2–MCM-41. The activity of both the hom...

When Professor Luis Oro turns over the middle of June, he will be 70 years old, and he will be completing a cycle of almost half a century (48 years) dedicated to chemical research in the field of organometallics and homogeneous catalysis, and in general to the development of chemistry. In this aim, he has assumed different and complementary respon...

Metallaheteroboranes are versatile compounds that can be conveniently modified and eventually tailored by ligand modification at either the metal centre or the boron vertices. Recently, we have discovered that protonation of some rhodathiaboranes affords cationic clusters with interesting reaction chemistry. In order to tune the reactivity of some...

Experimental and theoretical studies on the factors that control the coordination chemistry of N-donor ligands in square-planar complexes of type RhCl(NHC)L1L2 (NHC = N-heterocyclic carbene) are presented. The dinuclear complexes [Rh(μ-Cl)(IPr)(η2-olefin)]2 {IPr = 1,3-bis-(2,6-diisopropylphenyl)imidazol-2-carbene}, have been reacted with different...

New 10-vertex rhodathiaboranes are reported to exhibit reversible reaction chemistry leading to the formation of schoichiometric cycles driven by the hydrogenation of the alkene ligand.

The reaction between the 11-vertex rhodathiaborane [8,8-(PPh3)2-nido-8,7-RhSB9H10] (1) and 3-pyridylacetonitrile affords the hydrorhodathiaborane [8,8,8-(PPh3)2H-9-(3-Py-CH2CN)-nido-8,7-RhSB9H9] (2) in good yield. Treatment of this cluster with ethylene leads to the formation of red, [1,1-(PPh3)(η 2 -C2H4)-3-(3-Py-CH2CN)-closo-1,2-RhSB9H8] (3). Bot...

The rhodium(I) complexes [Rh(Cl)(COD)(R-NHC-(CH2)3Si(OiPr)3)] [COD=cyclooctadiene; R=2,6-diisopropylphenyl (1 a); n-butyl (1 b)] are effective catalyst precursors for the homogeneous hydrodechlorination of benzyl chloride using HSiEt3 as hydrogen source. This reaction is selective to the formation of toluene. However, in presence of a stoichiometri...

Dichloromethane solutions of complex 1 catalyze both the aza-Diels–Alder (ADA) reaction of aldimines with cyclopentadiene and the aza-Friedel–Crafts (AFC) reaction between aldimines and indoles. Racemic adducts were obtained in both cases. NMR measurements of mixtures of the aldimine N-(4-methylbenzylidene)aniline (I) and 1, in a 20/1 molar ratio,...

The reaction of the 11-vertex rhodathiaborane, [8,8-(PPh3)2-nido-8,7-RhSB9H10] (1), with NH3 affords inmediately the adduct, [8,8,8-(NH3)(PPh3)2-nido-8,7-RhSB9H10] (4). The NH3-Rh interaction induces the labilization of the PPh3 ligands leading to the dissociation product, [8,8-(NH3)(PPh3)-nido-8,7-RhSB9H10] (5), which can then react with another m...

The complex [Rh(μ-Cl)(IPr)(η2-coe)]2 {IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-carbene, coe = cis-cyclooctene} efficiently catalyzes the coupling of alkynes and N-vinylpyrazole via C–H activation, leading to Markovnikov-selective butadienylpyrazole derivatives under mild conditions. A straightforward approach to cross-conjugated acyclic trien...

Complexes of the formula [(η(n)-ring)M(){}][SbF6]2 ((η(n)-ring)M = (η(5)-C5Me5)Rh, (η(5)-C5Me5)Ir, (η(6)-p-MeC6H4iPr)Ru; = hydroxymethylpyridine ligand; {} = (R)-monophos) have been prepared from the corresponding dimers [{(η(n)-ring)MCl}2(μ-Cl)2] through routes involving [(η(5)-C5Me5)RhCl2{}] or [(η(n)-ring)MCl()][SbF6] intermediates. The new comp...

In the presence of phosphanes (PR3), the amido-bridged trinuclear complex [{Ir(μ-NH2)(tfbb)}3] (tfbb=tetrafluorobenzobarrelene) transforms into mononuclear discrete compounds [Ir(1,2-η2-4-κ-C12H8F4N)(PR3)3], which are the products of the CN coupling between the amido moiety and a vinylic carbon of the diolefin. An alternative synthetic approach to...

The synthesis and structural characterization of zwitterionic [(η(6)-C6H5-BPh3)M(coe)2] (M = Rh, Ir) cyclooctene complexes is described. Both complexes exhibit an unusual exo-endo conformation of both cyclooctene ligands in the solid state. However, an equilibrium between the endo-endo and exo-endo rotational isomers arising from the hindered rotat...

The coordinated OH group in cationic complexes [{eta(n)-ring)M(NOH)(Solv)][SbF6] and [(eta(n)-ring)M(NOH){(R)-P1}][SbF6](2) ((eta(n)-ring)M = (eta(5)-C5Me5)Rh, (eta(5)-C5Me5)Ir, (eta(6)-p-MeC(6)H(4)iPr)Ru; NOH = hydroxypyridine ligand; (R)-P1 = (R)-monophos) is deprotonated by Na2CO3, rendering bi- or mononuclear compounds of formulas [{(eta(n)-rin...

A series of neutral and cationic RhIII-hydride and RhIII-ethyl complexes bearing a NHC ligand has been synthesized and evaluated as catalyst precursors for H/D exchange of styrene using CD3OD as a deuterium source. Various ligands have been examined in order to understand how the stereoelectronic properties can modulate the catalytic activity. Most...

The reaction between pyridine and [8,8-(PPh3)(2)-nido-8,7-RhSB9H10] (1) has given the opportunity to synthesize a new family of 11-vertex hydridorhodathiaboranes that feature boron-bound N-heterocyclic ligands. To explore the scope of this reaction, 1 has been treated with the methylpyridine isomers (picolines) 2-Me-NC5H4, 3-Me-NC5H4, and 4-Me-NC5H...

The aqua complex (S-Ir,R-C)-[(eta(5)-C5Me5)Ir(Prophos)(H2O)][SbF6](2) [Prophos = (R)-propane-1,2-diyl-bis(diphenylphosphane)] is an active precursor for the asymmetric Diels-Alder reaction of acyclic enals with cyclopentadiene, 2,3-dimethylbutadiene and isoprene. Enantioselectivities up to 78% ee are achieved. The intermediate Lewis acid-dienophile...

Previously, we demonstrated that 11-vertex rhodathiaborane [8,8,8-(H)(PPh3)2-9-(NC5H5)-nido-8,7-RhSB9H9] (1) is capable of acting as a catalyst in the hydrogenation and isomerization of alkenes, showing reversible closo-to-nido flexibility1,2. Encouraged by the results involving this 11-vertex {SB9}-system, we started searching for high yield synth...

The phosphane-hydroxyl ligand (S-C1,R-C2)-Ph2PC(Ph)HC(OH)HCH2OMe (POH) displays kappa P-1, kappa P-2,O, kappa P-3,O,O', and anionic deprotonated kappa P-3,O,O' coordination modes toward the metallic (eta(6)-p-MeC(6)H(4)iPr)Ru moiety. The hydroxyl group in [(eta(6)-p-MeC(6)H(4)iPr)Ru(kappa P-3,O,O'-POH)][SbF6](2) (3) has strong acidic properties. Th...

The half-sandwich aqua complex (S-Rh,R-C)-[(eta(5)-C5Me5)Rh{(R)-Prophos}(H2O)][SbF6](2) (Prophos = propane-1,2-diylbis(diphenylphosphane)) efficiently catalyzes the asymmetric reaction between N-methyl-2-methylindole and trans-beta-nitrostyrenes (up to 94% ee). The metal-nitroalkene complex involved has been characterized by X-ray crystallography,...

The new rhodium(I) complexes [Rh(Cl)(COD)(R-NHC-(CH2)3Si(OiPr3)3)] (R = 2,6-diisopropylphenyl (2a); n-butyl (2b)) have been synthesised and fully characterised. The study of their application as ketone hydrosilylation catalysts showed a clear N-substituent effect, 2a being the most active catalyst precursor. Complex 2a has been immobilised in the m...

A series of dinuclear pyridine-4-thiolate (4-Spy)-bridged rhodium and iridium compounds [M(μ-4-Spy)(diolef)]2 [diolef = 1,5-cyclooctadiene (cod), M = Rh (1), Ir (2); diolef = 2,5-norbornadiene (nbd), M = Rh (3)] were prepared by the reaction of Li(4-Spy) with the appropriate compound [M(μ-Cl)(diolef)]2 (M = Rh, Ir). The dinuclear compound [Rh(μ-4-S...

Selected secondary phosphanes (H-PR2; R = Ph, Cy, (i)Pr) smoothly react with a parent amido-bridged diiridium cyclooctadiene complex affording mixed amido/(bis)phosphido dinuclear species. A careful investigation of the reaction profile, carried out by experimental and theoretical tools, revealed that, after an initial amido/phosphido exchange, at...

The σ,π-cyclooctenyl iridium(III) pincer compounds [Ir(κ3-pydc-X)(1-κ-4,5-η-C8H13)] (X = H (1), Cl, Br) have been prepared from [Ir(μ-OMe)(cod)]2 and the corresponding 4-substituted pyridine-2,6-dicarboxylic acids (H2pydc-X) or, alternatively, from their lithium salts (X = H) and [Ir(cod)(CH3CN)2]PF6. Deuterium labeling studies in combination with...

The unsaturated σ,π-cyclooctenyl iridium(III) pincer compound [Ir(κ3-hqca)(1-κ-4,5-η-C8H13)] (1) has been prepared by the reaction of [Ir(cod)(CH3CN)2]BF4 with lithium 8-oxidoquinoline-2-carboxylate (Li2hqca) and obtained as two isomers derived from the relative disposition of the pincer and the σ,π-cyclooctenyl ligands. Compound 1 can be prepared...

The new Rh–hydroxo dinuclear complexes stabilized by an N-heterocyclic carbene (NHC) ligand of type [Rh(μ-OH)(NHC)(η2-olefin)]2 (coe, IPr (3), IMes (4); ethylene, IPr (5)) are efficient catalyst precursors for alkyne hydrothiolation under mild conditions, presenting high selectivity toward α-vinyl sulfides for a varied set of substrates, which is e...

The treatment of the hydridorhodathiaboranes, [8,8,8-(H)(PR3)2-9-(Py)-nido-8,7-RhSB9H9], where PR3 = PPh3 (), PMePh2 (), PPh3 and PMe2Ph (), or PMe3 and PPh3 (), and [8,8,8-(H)(PMePh2)2-9-(PMePh2)-nido-8,7-RhSB9H9] (), with TfOH affords [8,8,8-(H)(PR3)2-9-(Py)-nido-8,7-RhSB9H10](+) cations, where PR3 = PPh3 (), PMePh2 (), PPh3 and PMe2Ph (), or PMe...

A new mechanism of H2 activation is reported to occur on a carbene-ligated rhodathiaborane that features metal-thiaborane bifunctional synergistic effects. The key is the creation of vacant coordination sites by an isonido-nido structural transformation leading to the heterolytic H-H bond splitting.

A series of ferrocenyl and cyrhetrenyl benzimidazoles were synthesized and characterized. The condensation-cyclization reaction of cyrhetrenecarbaldehyde with 1,2-phenylendiamine or 4-nitro-1,2-phenylendiamine produces only the 2-cyrhetrenyl-benzimidazoles [1-Re-(H, NO2)] whereas with the same diamines, ferrocenecarbaldehyde yields two products: 2-...

Condensation of homochiral primary amines with 1-methyl-1H-imidazole-2-carbaldehyde affords the corresponding imidazolyl-imine compounds () which have been employed as ligands for the preparation of half-sandwich rhodium and iridium complexes of the formula [(η(5)-C5Me5)MCl][SbF6]. Treatment of these chloride compounds with AgSbF6 renders dicationi...

The neutral square-planar complexes Rh(acac)(IPr)(η2-olefin) have been prepared from [Rh(μ-Cl)(IPr)(η2-olefin)]2 (IPr = 1,3-bis-(2,6-diisopropylphenyl)imidazol-2-carbene; olefin = cyclooctene, ethylene) and sodium acetylacetonate (acac). Protonation of the acetylacetonato complexes with triflic acid opens the way to the formation of the putative ba...

The ready availability of rare parent amido d(8) complexes of the type [{M(μ-NH2)(cod)}2] (M=Rh (1), Ir (2); cod=1,5-cyclooctadiene) through the direct use of gaseous ammonia has allowed the study of their reactivity. Both complexes 1 and 2 exchanged the di-olefines by carbon monoxide to give the dinuclear tetracarbonyl derivatives [{M(μ-NH2)(CO)2}...

Reaction of the dimer [Ir(mu-Cl)(eta(2)-coe)(2)](2) (coe = cyclooctene) with chiral phosphano oxazoline ligands (PN*) renders neutral mononuclear iridium(I) complexes of the formula [IrCl(eta(2)-coe)(PN*)] (1, 2), which in turn are oxidized to the corresponding iridium(III) hydride species [IrCl2H(eta(2)-coe)(PN*)] (3, 4) by treatment with aqueous...

The synthesis and characterization of cationic iridium(III) aqua complexes of the formula [IrH(H2O)(PN*)(PP)][SbF6](2) (PN* = chiral phosphano oxazoline ligand; PP = diphosphane) as well as that of the OPOF2-containing complex [IrH(OPOF2)(PNiPr)(dppp)][SbF6] (10) are reported. The X-ray molecular structures of [IrH(H2O)(PNInd)(dppe)][SbF6](2) (1),...

The treatment of [1,1-(PR ) -3-(Py)-closo-1,2-RhSB H ] (PR =PMe (2) or PPh and PMe (3); Py=pyridine) with triflic acid (TfOH) affords [1,3-μ-(H)-1,1-(PR ) -3-(Py)-1,2-RhSB H ] (PR =PMe (4) or PMe and PPh (5)). These products result from the protonation of the 11-vertex closo-cages along the Rh(1)B(3) edge. These unusual cationic rhodathiaboranes a...

The reaction of [Rh(μ-SH)(CO)(PPh(3))](2) or [Rh(μ-SH){P(OPh)(3)}(2)](2) with [Cp*MCl(2)](2) (M = Rh, Ir) in the presence of NEt(3) afforded the Rh(3) and IrRh(2) sulfido-bridged compounds [Cp*M(μ(3)-S)(2)Rh(2)(CO)(2)(PPh(3))(2)] (M = Rh, ; Ir, ) and [Cp*Rh(μ(3)-S)(2)Rh(2){P(OPh)(3)}(4)] (). The reaction with [MCl(2)(cod)] (M = Pd, Pt), cis-[PtCl(2...

Reactions of [8,8,8-(H)(PPh(3))(2)-9-(Py)-nido-8,7-RhSB(9)H(9)] (1), [1,1-(PPh(3))(2)-3-(Py)-closo-1,2-RhSB(9)H(8)] (2), and [1,1-(CO)(PPh(3))-3-(Py)-closo-1,2-RhSB(9)H(8)] (4), where Py = Pyridine, with HCl to give the Cl-ligated clusters, [8,8-(Cl)(PPh(3))-9-(Py)-nido-8,7-RhSB(9)H(9)] (3) and [8,8,8-(Cl)(CO)(PPh(3))-9-(Py)-nido-8,7-RhSB(9)H(8)] (...

The technique of high-pressure crystallisation from solution has been applied to the study of α-cyclodextrin hydrate formation. A previously unobserved hydrate, here termed Ib, has been obtained at 0.65 GPa and characterised by single-crystal X-ray diffraction using synchrotron radiation. This form exhibits a combination of structural features of o...