811-73-4Relevant academic research and scientific papers
A catalytic and mechanistic investigation of a PCP pincer palladium complex in the Stille reaction
Olsson, Daniel,Nilsson, Patrik,El Masnaouy, Mostafa,Wendt, Ola F.
, p. 1924 - 1929 (2007/10/03)
In an improved procedure, the complex {2,6-bis[(diphenylphosphino)methyl] benzene}chloropalladium(II) (1) was synthesised as its THF adduct and the structure was determined by X-ray crystallography. The catalytic properties of the derivative {2,6-bis[(diphenylphosphino)methyl]benzene}(trmuoroacetato) palladium(II) (2) was investigated in the Stille reaction. Complex 2 proves to be an excellent catalyst for the C-C cross-coupling between trimethyl phenyl stannane and aryl bromides using a very low catalyst loading (0.1-0.0001%), giving high turnover numbers (TONs) up to 6.9 × 105. A kinetic investigation of the catalytic reaction suggests a heterogeneous colloidal palladium catalyst formed from the PCP Pd(II) pre-catalyst. The Royal Society of Chemistry 2005.
Cine-Substitution in the Stille Coupling: Evidence for the Carbenoid Reactivity of sp3-gem-Organodimetallic Iodopalladio-trialkylstannylalkane Intermediates
Fillion, Eric,Taylor, Nicholas J.
, p. 12700 - 12701 (2007/10/03)
Two complementary routes to sp3-gem-organodimetallic iodopalladio-trialkylstannanylalkanes are presented. Such intermediates have been proposed as Pd-carbenoid precursors in the Busacca-Farina cine-substitution mechanism in the Stille coupling. The decomposition of iodomethyltrialkylstannanes by Pd(0) catalysts was monitored by 1H, 2D, and 119Sn NMR. The formation of ethylene, trace formaldehyde, and iodotrialkylstannanes was detected. When the reaction was carried out in the presence of norbornene, the corresponding cyclopropane was produced in good yield. These observations are consistent with the intermediacy of a Pd-carbenoid species. sp3-gem-Organodimetallic iodopalladio-trialkylstannanylalkane complexes were also prepared under stoichiometric conditions via transmetalation from tin to Pd(II). Me3SnCH2Sn(CH2CH2CH2)3 reacted with [(D-t-BPF)PdI]+I-, yielding the (D-t-BPF)Pd(II)ICH2SnMe3 complex that dimerized to form ethylene and cyclopropanated norbornene. The carbenoid reactivity of iodopalladio-trialkylstannanylalkanes complexes validates the Busacca-Farina mechanism of the cine-substitution in the Stille coupling. Copyright
Synthesis and structure of tris(trialkylstannyl)- and tris(dialkylhalostannyl)amines; of the Sn3N by Sn-X-Sn
Appel, Andrea,Kober, Christian,Neumann, Christine,Noeth, Heinrich,Schmidt, Martin,Storch, Wolfgang
, p. 175 - 189 (2007/10/02)
Tris(triorganylstannyl)amines (R2R′Sn)3N (1, 2) with substituents R = R′ = Me, Bu or R = Me and R′ = iPr, tBu are obtained by metathesis from R2R′SnX and NaNH2 in liquid ammonia or by transamination of R3SnNMe2 with NH3. Tris(diorganylhalostannyijamines (R2XSn)3N (3) are synthesized by stannazane cleavage of (Me3Sn)3N (1) with R2SnX2. Information from multinuclear magnetic resonance spectra ascertain the planarity of the Sn3N skeleton of type 2 and 3, as well as the relationship between the coupling constants 1J(119Sn15N) and 2J(119Sn117Sn) and the Sn-N bond length as determined by the X-ray structure analysis of 1, 3b and 3r. Compound 3b shows an almost undistorted D3h symmetry with a planar Br3Sri3N skeleton and SnN bond lengths of 1.99 A, which beside those of 3a are the shortest found so far. According to MNDO approximate and ab initia calculations it interactions between the lone electron pair at the N atom and empty orbitals at the Sn atoms can be excluded. Therefore, the tristannylamines discussed here have a trigonal planar nitrogen center with its lone electron pair in a p-type orbital. Further characteristic features of the molecular structures of typ 3 compounds are the intramolecular Sn-X-Sn bridges (X = Cl, Br, I) found in the solid state as well as in solution. The molecular geometries of the tristannylamines are supported by MS fragmentation patterns as well as by infrared and Raman spectra. VCH Verlagsgesellschaft mbH 1996.
Synthesis and Properties of Trimethyl(trifluorosilyl)stannane
D'Errico, John,Sharp, Kenneth G.
, p. 1879 - 1882 (2007/10/02)
Trimethyltin hydride reacts with SiF3SiF3 or SiF3SiF2H to give the new compound SnMe3(SiF3) in 75-80 percent yield.No reaction was observed between SnMe3H and SiF3SiH3.Hydrogen-deuterium exchange was observed between tin and silicon during the course of deuterium-labelling experiments.Dimethylstannylene (SnMe2) was implicated as an intermediate by trapping experiments in the thermolysis of SnMe3(SiF3).
Electrophilic cleavages in (CH3)3SnCH2M(CH3)3 (M = Sn, Ge, Si, C). 1. Product distribution
Hawker, Darryl W.,Wells, Peter R.
, p. 821 - 825 (2008/10/08)
The extent to which Sn-CH2 and/or Sn-CH3 cleavage occurs in (CH3)3SnCH2M(CH3)3 (M = Sn, Ge, Si) in reactions with several electrophiles has been determined. With iodine and with
TRIORGANOTIN ARYL SELENIDES
Grant, Douglas W.,Wardell, James L.
, p. 161 - 166 (2007/10/02)
The Sn-Se bond in trimethyltin aryl selenides is cleaved on reaction with selenenyl halides, sulphenyl halides, alkyl halides and allyl halides.Thus Me3SnSePh reacts with PhSeCl, 4-Me-2-NO2C6H3SCl, RI (R = CH3 or Ph3SnCH2) and CH2=CHCH2Br to give PhSeSePh, 4-Me-2-NO2C6H3SSePh, RSePh and CH2=CHCH2SePh, respectively.The diselenide, PhSeSePh, is also obtained from Me3SnSePh on reaction with either 4-MeC6H4SO2Cl or NaIO4.Exchange reactions also occur between Me3SnSePh and Ph3SnCl or PhHgCl.
DESULPHURIZATION OF SULPHUR-CONTAINING ORGANOMETALLIC COMPOUNDS
Razuvaev, G.A.,Shcherbakov, V.I.,Grigor'Eva, I.K.
, p. 245 - 252 (2007/10/02)
Desulphurization reactions of trialkyl- and dialkyl-tin sulfides with a variety of reagents such as acyclic peroxides, salts and organic derivatives of some metals, halogen alkanes, as well as with sulphur acceptors such as copper powder or triphenylphosphine are discussed.
REACTIONS OF ORGANOMETALLIC COMPOUNDS, CATALYZED BY COMPLEXES OF TRANSITION METALS. II. FORMATION OF TIN-CARBON BOND IN REACTION OF HEXAMETHYLDISTANNANE WITH ORGANIC HALIDES, CATALYZED BY PALLADIUM COMPLEXES
Kashin, A. N.,Bumagina, I. G.,Bumagin, N. A.,Bakunin, V. N.,Beletskaya, I. P.
, p. 789 - 794 (2007/10/02)
he reactions of Me6Sn2 with ArI (Ar = Ph, p-NO2C6H4), catalyzed by ArPdI(PPh3)2, and also the stoichiometric reactions of Me6Sn2 with ArPdI(PPh3)2 (in methylene chloride, 20-60 deg C), which lead to the formation of ArSnMe3, were investigated.These reactions are only realized in the presence of Et4NCl.In the reactions of Me6Sn2 with RX (where R = Ph, o-, m-, and p-NO2C6H4, 2,4-(NO2)2C6H3, o-MeOOCC6H4, X = I, and R = CH2=CHCH2, 2-cyclohexenyl, X = Br) catalyzed by bis(?-allylpalladium chloride) (in methylene chloride, 20 deg C) RSnMe3, compounds are obtained with high yields.The possible reaction mechanisms are discussed.
SUBSTITUTION AT SATURATED CARBON. PART 25. THE IODODEMETALLATION OF BENZYLTRIALKYLTINS IN METHANOL
Abraham, Michael H.,Andonian-Haftvan, Jenik
, p. 819 - 830 (2007/10/02)
The action of I2/I- in methanol on compounds PhCH2SnR3 leads only to cleavage of the benzyl group (as PhCH2I) when R=Et, Prn or Bun.With PhCH2SnMe3, both benzyl and methyl groups are removed.Rate constants are reported for the iododemetallation of all four PhCH2SnR3 compounds, R=Me, Et, Prn and Bun.The present results and previous literature data show that with a constant SnR3 leaving group, the sequence of alkyl-tin reactivity is Ph>PhCH2>Me>Et>Prn, with the benzyl-tin bond being broken 3-4 times as rapidly as the methyl-tin bond and about 40 times as rapidly as the ethyl-tin bond.The effect of added anions, Cl-, Br-, I- and ClO4- on the rate constants (and products) are reported, and it is shown that both kinetic studies and product analyses lead to the conclusion that foreign anions do not participate in the reaction mechanism.These are, however, specific kinetic salt effects in the order NaBrNaClNaClO4NaI.
