- Antimony(v) cations for the selective catalytic transformation of aldehydes into symmetric ethers, α,β-unsaturated aldehydes, and 1,3,5-trioxanes
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1-Diphenylphosphinonaphthyl-8-triphenylstibonium triflate ([2][OTf]) was prepared in excellent yield by treating 1-lithio-8-diphenylphosphinonaphthalene with dibromotriphenylstiborane followed by halide abstraction with AgOTf. This antimony(v) cation was found to be stable toward oxygen and water, and exhibited exceptional Lewis acidity. The Lewis acidity of [2][OTf] was exploited in the catalytic reductive coupling of a variety of aldehydes into symmetric ethers of type L in good to excellent yields under mild conditions using Et3SiH as the reductant. Additionally, [2][OTf] was found to selectively catalyze the Aldol condensation reaction to afford α-β unsaturated aldehydes (M) when aldehydes with 2 α-hydrogen atoms were used. Finally, [2][OTf] catalyzed the cyclotrimerization of aliphatic and aromatic aldehydes to afford the industrially-useful 1,3,5 trioxanes (N) in good yields, and with great selectivity. This phosphine-stibonium motif represents one of the first catalytic systems of its kind that is able to catalyze these reactions with aldehydes in a controlled, efficient manner. The mechanism of these processes has been explored both experimentally and theoretically. In all cases the Lewis acidic nature of the antimony(v) cation was found to promote these reactions.
- Arias Ugarte, Renzo,Devarajan, Deepa,Mushinski, Ryan M.,Hudnall, Todd W.
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supporting information
p. 11150 - 11161
(2016/07/20)
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- Structural, spectroscopic and computational examination of the dative interaction in constrained phosphine-stibines and phosphine-stiboranes
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Abstract A series of phosphine-stibine and phosphine-stiborane peri-substituted acenaphthenes containing all permutations of pentavalent groups -SbClnPh4-n (5-9), as well as trivalent groups -SbCl2, -Sb(R)Cl, and -SbPh2 (2-4, R=Ph, Mes), were synthesised and fully characterised by single crystal diffraction and multinuclear NMR spectroscopy. In addition, the bonding in these species was studied by DFT computational methods. The P-Sb dative interactions in both series range from strongly bonding to non-bonding as the Lewis acidity of the Sb acceptor is decreased. In the pentavalent antimony series, a significant change in the P-Sb distance is observed between -SbClPh3 and -SbCl2Ph2 derivatives 6 and 7, respectively, consistent with a change from a bonding to a non-bonding interaction in response to relatively small modification in Lewis acidity of the acceptor. In the SbIII series, two geometric forms are observed. The P-Sb bond length in the SbCl2 derivative 2 is as expected for a normal (rather than a dative) bond. Rather unexpectedly, the phosphine-stiborane complexes 5-9 represent the first examples of the σ4P→σ6Sb structural motif. A complex situation: The strength of a dative phosphine-stiborane (P-Sb) interaction increases with stepwise replacement of phenyl groups on antimony atom with chloride groups. As the Lewis acidity is increased in regular steps (see figure), essentially linear response is observed initially, however then a sudden change in the P-Sb distance takes place during one particular step. This is consistent with a sudden switch from a non-bonding to a bonding interaction, that is, a discrete rather than continuum response.
- Chalmers, Brian A.,Bühl, Michael,Athukorala Arachchige, Kasun S.,Slawin, Alexandra M. Z.,Kilian, Petr
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supporting information
p. 7520 - 7531
(2015/05/13)
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- Triorganoantimony(V) carboxylates: Synthesis, characterization and crystal structure of [Me3Sb(O2C-C5H4N)2] · H2O
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Reactions of [R3Sb(OPri)2] with N-heterocylic carboxylic acids gave compounds of the type [R3Sb(O2C-Ar)2] (1) (R = Me, Et, Pri, Ph; Ar = 2-C5H4N, 2-C9
- Chaudhari, Kamal R.,Jain, Vimal K.,Sagoria,Tiekink, Edward R.T.
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p. 4928 - 4932
(2008/03/13)
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- Synthesis and Structure of Triarylantimony Bis(arenesulfonates)
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Triarylantimony bis(arenesulfonates) were prepared by reaction of triarylantimonies with hydrogen peroxide in the presence of arenesulfonic acids. The steric structure of the products was assessed. Triarylantimony bis(arenesulfonates) were reacted with so
- Sharutin,Sharutina,Platonova,Pakusina,Panova,Fukin,Zakharov
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p. 354 - 357
(2007/10/03)
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- Phenylation of Antimony(V) Organic Compounds with Pentaphenylantimony. The Structure of Tetraphenylantimony Chloride
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Tetraphenylantimony chloride and bromide were synthesized through the reaction of pentaphenylantimony with diphenylantimony trichloride or tribromide taken at a molar ratio of 2:1 in toluene. When the initial compounds were taken at a molar ratio of 1:1, triphenylantimony dichloride or dibromide was formed. The phenylation of triphenylantimony sulfate with pentaphenylantimony yielded tetraphenylantimony sulfate. According to the X-ray diffraction data, the antimony atom in the tetraphenylantimony chloride molecule has a distorted trigonal bipyramidal configuration with the chlorine atom in the axial position. The Sb-Cl distance is equal to 2.686(1) and Sb-C distances are equal to 2.113(4) and 2.165(4) A (av. 2.130 A).
- Sharutin,Sharutina,Pakusina,Platonova,Zadachina,Gerasimenko
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- Pd-catalyzed C-arylation of unsaturated compounds with pentavalent triarylantimony dicarboxylates
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Triarylantimony (V) derivatives Ar3SbX2 (X = Hal or acyloxy) were prepared by reaction of Ar3Sb with equimolar amounts of a peroxide ROOH (R = t-Bu, H) in the presence of an acid or an anhydride in good to excellent yields. Ar3Sb(O2CR)2 are mild and efficient C-arylation reagents of unsaturated compounds (methyl acrylate, styrene, 2-phenylpropene and acrylonitrile) under palladium catalysis at 50 °C, with PdCl2 being the most effective catalyst. Ar3SbHal2 do not react under these conditions.
- Moiseev, Dmitry V.,Gushchin, Aleksey V.,Shavirin, Andrey S.,Kursky, Yury A.,Dodonov, Viktor A.
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p. 176 - 184
(2007/10/03)
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- Reactions of Pentaarylantimony with Triarylantimony Diacylates
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Tetraarylantimony acylates were obtained from pentaarylantimony and triarylantimony diacylates in 87-98% yields. According to X-ray diffraction data, triphenylantimony dicynnamate Ph3Sb[OC(O)CH= CHPh]2, tetra-p-tolyl monophthalate (p-CH3C6H4)4SbOC(O)C 6H4COOH-o, and tetraphenylantimony salicylate Ph4SbOC(O)C6H4OH-o are trigonal-bipyramidal antimony complexes having axial carboxylic moieties. In the first and third compounds, antimony is coordinated at the esteric carbonyl oxygen, and in the second and third compounds, the carbonyl oxygen enters intramolecular H bonding with the hydrogen atoms of the free carboxy (hydroxy) groups.
- Sharutin,Sharutina,Pakusina,Bel'skii
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p. 1443 - 1448
(2007/10/03)
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- Studies on Synthetic and Structural Aspects of Unsymmetrical Tetraorganoarsonium and stibonium Halides, Pseudohalides and Carboxylates : Electrophilic Cleavage of M-Allyl Bond
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Triphenylarsine and triphenylstibine react with allyl bromide to give the corresponding allyltriphenylarsonium and stibonium laclides. The metal-allyl bond is readily cleaved by electrophiles, such as Br2, I2, ICI and IBr. Metathetical reactions involving allyltriphenytarsonium and stibonium halides and the appropriate metal salts, M'X(M' = Na, K, Ag; X = NCS, NCO, N3, CH3COCO, CCl3COO, C6H5COO) have been employed to yield a series of new compounds. The compounds are monomeric in beazine solution and 1 : 1 electrolyte in nitromethane.
- Singh Raizada, Meenu,Srivastava
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p. 646 - 649
(2008/10/09)
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- Structural Investigations of the Organoantimony(V) Halides Ph4SbX and Ph3SbX2 (X = Cl, Br or I) in the Solid State and in Solution
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X-Ray crystallography revealed a distorted trigonal-bipyramidal structure for Ph4SbI, with Sb-Cax 2.141(3), Sb-Ceq 2.103(3)-2.117(3) Angstroem and a long Sb-I distance of 3.341(1) Angstroem in monoclinic crystals of P21/n symmetry.Consideration of the weak Sb-X bonds in Ph4SbX (X = Cl, Br or I) leads to reassignment of their Raman spectra; Ph4SbI ionises forming (1+) in acetonitrile, as shown by 13C and 121Sb NMR spectra.The halide Ph3SbI2 is reported in two phases, yellow, orthorombic (Fdd2) crystals isomorphous with Ph3SbBr2 and off-white, cubic (P4332) crystals.In each the molecule is trigonal-bipyramidal, with axial Sb-I bonds of 2.865(1) Angstroem in the former and 2.885(1) Angstroem in the latter, and small differences in their respective bond angles.The phenyl groups of the cubic form are in the regular propeller arrangement whereas one group of the orthorhombic form has a reversed orientation.The vibrational spectra of the two forms differ slightly.
- Baker, Lisa-Jane,Rickard, Clifton E. F.,Taylor, Michael J.
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p. 2895 - 2900
(2007/10/03)
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- Solid-state Structures of Triarylantimony Dihalides; the Isolation of Some Mixed-halide Species and Crystal Structures of Ph3SbI2 and I3
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Fifteen compounds of stoichiometry R3SbX2 (R = Ph or substituted aryl; X2 = Br2, I2 or IBr) were synthesized and studied by Raman spectroscopy.The crystal structure of Ph3SbI2 has been determined, which shows it to be a distorted trigonal-bipyramidal molecule.The distortion from regular trigonal-bipyramidal geometry may be explained by a pseudorotation process towards a rectangular pyramid.Moreover, there are two independent molecules within the unit cell and its distorted structure is in direct contrast to the known Ph3SbX2 (X = Cl or Br) which both adopt regular trigonal-bipyramidal geometry.The interhalogen compounds R3SbIBr also have trigonal-bipyramidal geometry.In direct contrast to the molecules Ph3El2 (E = P or As), which ionise in solution to form I, Ph3SbI2 is chemically changed in acetonitrile solution and forms the ionic I3, there being no evidence for I.The crystal structure of I3 has also been determined.
- Bricklebank, Neil,Godfrey, Stephen M.,Lane, Helen P.,McAuliffe, Charles A.,Pritchard, Robin G.
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p. 1759 - 1764
(2007/10/02)
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- Cleavage of Pentaphenyl Arsenic and Antimony Derivatives with Halogens and Interhalogens
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Facile and specific cleavage of metal-carbon bond(s) has been found to occur when pentaphenyl-arsenic or-antimony derivatives are treated with halogens (Br2, I2) and inter-halogens (ICl, IBr) under controlled conditions.
- Raizada, Meenu Singh,Nigam, H. L.
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p. 722 - 724
(2007/10/02)
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- Donor Properties of Triphenylantimony Dihalides: Preparation and Crystal Structures of Ph3SbCl2*SbCl3 and
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Triphenylantimony dichloride reacts with both antimony(III) and antimony(V) chloride to give addition compounds with the stoicheiometry Ph3SbCl2*SbCl3 and Ph3SbCl2*SbCl5, respectively.X-Ray analysis of the former shows the presence of only weak interactions between the axial chlorine atoms of Ph3SbCl2 and adjacent SbCl3 molecules to give polymeric chains parallel to the a axis.The trigonal bipyramidal geometry of Ph3SbCl2 is little changed; co-ordination about SbIII is square pyramidal with three short (mean 2.337 Angstroem) and two long (mean 3.262 Angstroem) distances.In the SbCl5 compound there is a chloride ion transfer to SbCl5 giving a structure best described in terms of the ionic formulation +-.Residual anion-cation interaction is shown by a Cl...Sb contact of 3.231 Angstroem, and the cation geometry is intermediate between the trigonal pyramidal and tetrahedral extremes.Reactions between Ph3SbX2 (X = F, Br, or I) and SbCl3, SbBr3, or SbCl5 are also described.
- Hall, Michael,Sowerby, D. Bryan
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p. 1095 - 1100
(2007/10/02)
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