A5011788637- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Organometallic Complex Synthesis and Catalysis
- Asymmetric Hydrogenation and Catalysis
- Crystallography and molecular interactions
- Catalytic Cross-Coupling Reactions
- Organoboron and organosilicon chemistry
- Catalytic C–H Functionalization Methods
- Fluorine in Organic Chemistry
- Synthetic Organic Chemistry Methods
- Coleoptera: Cerambycidae studies
- Hydrogen Storage and Materials
- Organic Light-Emitting Diodes Research
- Asymmetric Synthesis and Catalysis
- Lepidoptera: Biology and Taxonomy
- Cyclopropane Reaction Mechanisms
- Scarabaeidae Beetle Taxonomy and Biogeography
- Ionic liquids properties and applications
- Chemical Reactions and Isotopes
- Boron Compounds in Chemistry
- Oil Palm Production and Sustainability
- Radical Photochemical Reactions
- N-Heterocyclic Carbenes in Organic and Inorganic Chemistry
- Carbohydrate Chemistry and Synthesis
- Ammonia Synthesis and Nitrogen Reduction
Instituto de Síntesis Química y Catálisis Homogénea
2013-2023
Universidad de Zaragoza
2013-2023
Universidad de Valladolid
2018-2023
Heriot-Watt University
2010
University of Bath
1993-2010
Consejo Superior de Investigaciones Científicas
2010
9,9-Dimethyl-4,5-bis(diisopropylphosphino)xanthene (xant(P(i)Pr2)2) derivatives RhCl{xant(P(i)Pr2)2} (1) and I rHCl{xant(P(i)Pr2)[(i)PrPCH(Me) CH2]} (2) react with diphenylsilane triethylsilane to give the saturated d(6)-compounds RhHCl(SiR3){xant(P(i)Pr2)2} (SiR3 = SiHPh2 (3), SiEt3 (4)) IrHCl(SiR3){xant(P(i)Pr2)2} (5), (6)). Complexes 3 5 undergo a Cl/H position exchange process via MH{xant(P(i)Pr2)2} (M Rh (8), Ir (E)) intermediates. The rhodium complex affords square planar d(8)-silyl...
A combination of experimental studies and density functional theory calculations is used to study C-N bond activation in a series ruthenium N-alkyl-substituted heterocyclic carbene (NHC) complexes. These show that prior C-H the NHC ligand renders system susceptible irreversible activation. In presence source HCl, activated Ru(I(i)Pr(2)Me(2))'(PPh(3))(2)(CO)H (1, I(i)Pr(2)Me(2) = 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene) reacts give Ru(I(i)PrHMe(2))(PPh(3))(2)(CO)HCl (2, I(i)PrHMe(2)...
The square-planar monohydride complex RhH{xant(PiPr2)2} (1; xant(PiPr2)2 = 9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene) activates C–H bonds of arenes. Heating benzene solutions 1 at 80 °C affords RhPh{xant(PiPr2)2} (2). Under the same conditions, toluene gives Rh(m-tolyl){xant(PiPr2)2} (3a) and Rh(p-tolyl){xant(PiPr2)2} (3b) in a 78:22 molar ratio, whereas m-xylene leads to Rh(C6H3-3,5-Me2){xant(PiPr2)2} (4). At room temperature, fluorobenzene 1,3-difluorobenzene generate...
The stoichiometric reactions proposed in the mechanism of rhodium-mediated decyanative borylation have been performed and all relevant intermediates isolated characterized including their X-ray structures. Complex RhCl{xant(PiPr2)2} (1, xant(PiPr2)2 = 9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene) reacts with bis(pinacolato)diboron (B2pin2), benzene, to give rhodium(III) derivative RhHCl(Bpin){xant(PiPr2)2} (4) PhBpin. reaction involves oxidative addition B2pin2 1...
The pincer d(8)-monohydride complex RhH{xant(P(i)Pr2)2} (xant(P(i)Pr2)2 = 9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene) promotes the release of 1 equiv hydrogen from H3BNH3 and H3BNHMe2 with TOF50% values 3150 1725 h(-1), to afford [BH2NH2]n [BH2NMe2]2 tandem ammonia borane dehydrogenation-cyclohexene hydrogenation. DFT calculations on dehydrogenation suggest that process takes place by means cis-κ(2)-PP-species, through four stages including: (i) Shimoi-type coordination borane, (ii)...
Treatment of the dimer [Rh(μ-Cl)(C8H14)2]2 (1a) with 9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene [xant(P(i)Pr2)2] leads to d(8) square-planar complex RhCl{xant(P(i)Pr2)2} (2), whereas reaction iridium counterpart [Ir(μ-Cl)(C8H14)2]2 (1b) gives d(6) octahedral compound IrHCl{xant(P(i)Pr2)[(i)PrPCH(Me)CH2]} (3) as a result intramolecular C-H bond activation one isopropyl substituents phosphine. Stirring 2 and 3 in 0.5 N KOH solutions 2-propanol rise formation hydrides...
The C–Cl bond cis oxidative addition of 12 chloroarenes, including chlorobenzene, chlorotoluenes, chlorofluorobenzenes, and di- trichlorobenzenes to RhH{xant(PiPr2)2} (1; xant(PiPr2)2 = 9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene) the ability resulting rhodium(III) species undergo reductive elimination reactions are reported. Complex 1 reacts with chlorobenzene give RhHCl(C6H5){xant(PiPr2)2} (2), which eliminates benzene afford RhCl{xant(PiPr2)2} (3). On other hand, in presence...
The elemental steps for the preparation of (E)-pinBC(Me)═C(Me)Bpin (Bpin = pinacolboryl) by means anti addition B2pin2 to 2-butyne, promoted boryl complex Rh(Bpin){xant(PiPr2)2} (1; xant(PiPr2)2 9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene), have been analyzed from a kinetic point view, and intermediates process, β-borylakenyl complexes Rh{(Z)-C(Me)═C(Me)Bpin}{xant(PiPr2)2} (2) Rh{(E)-C(Me)═C(Me)Bpin}{xant(PiPr2)2} (3), isolated fully characterized. key step formation diborylalkene is...
The d2-hexahydride complex OsH6(PiPr3)2 (1) promotes the activation of C–H bonds 2,2′-bipyridines and related heterocycles. study same reactions with deuteride counterpart OsD6(PiPr3)2 (1-d) reveals that situated in sterically less hindered positions is kinetically preferred. However, isolated products are result thermodynamic control reactions. Thus, 1 2,2′-bipyridine, 6-phenyl-2,2′-bipyridine, 6-methyl-2,2′-bipyridine give "rollover cyclometalation" OsH3{κ2-C,N-[C5(R)H2N-py]}(PiPr3)2 (R =...
An unusual 1,3-hydrogen shift from the metal center to Cβ atom of C3-chain allenylidene ligand in a hydride-osmium(II)-allenylidene complex is beginning several interesting transformations cumulene. The was prepared two steps, starting tetrahydride dimer [(Os(H···H){κ3-P,O,P-[xant(P i Pr2)2]})2(μ-Cl)2][BF4]2 (1). Complex 1 reacts with 1,1-diphenyl-2-propyn-1-ol give hydride-osmium(II)-alkenylcarbyne [OsHCl(≡CCH=CPh2){κ3-P,O,P-[xant(P Pr2)2]}]BF4 (2), which yields...
The tris(boryl) complex Ir(Bcat)3{κ3-P,O,P-[xant(PiPr2)2]} [Bcat = catecholboryl; xant(PiPr2)2 9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene] has been prepared and characterized by X-ray diffraction analysis. boryl ligands are disposed in a mer arrangement. Ir–B bonds situated mutually trans ∼0.1 Å longer than that cis to the other two. An energy decomposition analysis method coupled natural orbitals for chemical valence revealed level of π-back-donation from metal pz atomic orbital...
Switching the solvent from toluene to dichloromethane results in a very important enhancement yield and enantiomeric excess of nucleophilic addition.
Reactions of polyhydrides OsH6(PiPr3)2 (1) and IrH5(PiPr3)2 (2) with rollover cyclometalated hydride complexes have been investigated in order to explore the influence a metal center on MHn unit other mixed valence binuclear polyhydrides. Hexahydride 1 activates an ortho-CH bond heterocyclic moiety trihydride metal-ligand compounds OsH3{κ2-C,N-[C5RH2N-py]}(PiPr3)2 (R = H (3), Me (4), Ph (5)). 3 4 lead hexahydrides (PiPr3)2H3Os{μ-[κ2-C,N-[C5RH2N-C5H3N]-N,C-κ2]}OsH3(PiPr3)2 (6), (7)), whereas...
Aza-pyridinoxazoline ligands, a new class of C(1)-symmetric are described and tested in the heterogeneous enantioselective catalysis cyclopropanation reaction, with aim improving surface confinement effects by clay support on reaction stereoselectivity. In case trans/cis diastereoselectivity, these lead to systematic reversal selectivity, cis-cyclopropanes being favored. Regarding enantioselectivities, has positive effect major cis-cyclopropane products, leading moderate enantioselectivity...
Pinacolborane, catecholborane, triethylsilane, triphenylsilane, dimethylphenylsilane, 1,1,1,3,5,5,5-heptamethyltrisiloxane, triethylgermane, triphenylgermane, and triphenylstannane deuterated at the heteroatom position have been catalytically prepared in 50–70% isolated yield, through H/D exchange between D2 molecule respective boranes hydrides of group 14 elements, presence rhodium(I)-monohydride catalyst precursor RhH{κ3-P,O,P-[xant(PiPr2)2]} (xant(PiPr2)2 =...
Reactions of the aryl complexes Rh(aryl){κ 3 -P,O,P-[xant(P i Pr 2 ) ]} (1; = 3,5-Me C 6 H (a), 5 (b), 3,5-Cl (c), 3-FC 4 (d); xant(P 9,9-dimethyl-4,5-bis-(diisopropylphosphino)xanthene) with O , CO, and MeO CC≡CCO Me have been performed. Under 1 atm pentane solutions afford dinuclear peroxide derivatives [Rh(aryl){κ -P,P-xant(P }] (μ-O (2a–2d) as yellow solids. In solution, these species are unstable. dichloromethane, at room temperature, they transformed into dioxygen adducts Rh(aryl)(η -O...
Two complementary procedures are presented to prepare
Complex OsH4{κ3-P,O,P-[xant(PiPr2)2]} (1) activates the Si-H bond of triethylsilane, triphenylsilane, and 1,1,1,3,5,5,5-heptamethyltrisiloxane to give silyl-osmium(IV)-trihydride derivatives OsH3(SiR3){κ3-P,O,P-[xant(PiPr2)2]} [SiR3 = SiEt3 (2), SiPh3 (3), SiMe(OSiMe3)2 (4)] H2. The activation takes place via an unsaturated tetrahydride intermediate, resulting from dissociation oxygen atom pincer ligand 9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene (xant(PiPr2)2). This which has been...
The PEWO phosphines R2P(o-C6H4CH═CHC(O)Ph), R2P(o-C6H2F2CH═CHC(O)Ph), and R2P(o-C6F4CH═CHC(O)Ph) their P-monodentate complexes trans-[PdCl2(P-monodentate)2] show, in solution (when available) the X-ray diffraction structures, an E configuration of double bond. In contrast, structures [PdCl2(P-chelate)] display Z configurations. E/Z isomerization latter requires first decoordination bond, which then allows for easy rotation about electron-deficient Thus, equilibria exist free as well but are...
The virulences of three isolates Fusarium oxysporum f.sp. elaeidis from West Africa were compared with that a Brazilian isolate. strain was more virulent and caused disease in all oil‐palm lines tested, even those which had been selected for resistance to, generally unaffected by, African strains. Differential interactions between hosts the pathogen could have serious implications selection breeding material extension cultivation South America.
The E phosphine ligands (R = Ph, o-Tol, Cy), abbreviated as RPEWO-F4, are stable in solution, but they develop a rich reactivity on coordination to PdCl2. chelate P-olefin PdCl2 leads eventually Z conformation of the fluorinated-chalcone group o-C6F4CH═CHC(O)Ph. From there, cyclization reaction occurs involving C═O and activation F atom, yielding strongly chelated PdCl2(P-carbene) complex. carbene carbon atom complex displays some electrophilicity, which is expressed hydrolysis, ammonolysis,...