- A utility for organoleads: Selective alkyl and aryl group transfer to tin
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Me4Pb and Ph4Pb readily transfer methyl or phenyl groups to an equivalent molar ratio of tin(iv) chlorides in the order SnCl4 > MeSnCl3 > Me2SnCl2 > Me3SnCl, often in a selective manner. Me3PbCl and Ph3PbCl specifically transfer a single methyl/phenyl group under the same reaction conditions to produce recovered yields in >75%. Specific transfer of 2 methyl groups from PbMe4 can be achieved at elevated temperatures and/or a 2:1 molar ratio Pb:Sn.
- Arias-Ugarte, Renzo N.,Pannell, Keith H.
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p. 1703 - 1708
(2018/02/09)
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- Direct Detection, Dimerization, and Chemical Trapping of Dimethyl- and Diphenylstannylene from Photolysis of Stannacyclopent-3-enes in Solution
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Dimethyl- and diphenylstannylene (SnMe2 and SnPh2, respectively) have been successfully detected and characterized in solution. The stannylenes were generated by photolysis of 1,1,3-trimethyl-4-phenyl- (2) and 3,4-dimethyl-1,1-diphenylstannacyclopent-3-ene (3), respectively, which have been shown to extrude the species cleanly and in high (0.6 2SnCl2) as the stannylene substrate. Laser flash photolysis of 2 and 3 in deoxygenated hexanes affords promptly formed transient absorptions assigned to SnMe2 (λmax = 500 nm; ε500 = 1800 ± 600 M-1 cm-1) and SnPh2 (λmax = 290, 505 nm; ε500 = 2500 ± 600 M-1 cm-1), respectively, which decay with absolute second-order rate constants within a factor of 2 of the diffusional limit in both cases. The decay of the stannylenes is accompanied by the growth of new transient absorptions ascribable to the corresponding dimers, the structures of which are assigned with the aid of DFT and time-dependent (TD) DFT calculations at the (TD)ωB97XD/6-31+G(d,p)C,H,O-LANL2DZdpSn level of theory. Dimerization of SnMe2 affords a species exhibiting λmax = 465 nm, which is assigned to the expected Sn=Sn doubly bonded dimer, tetramethyldistannene (Me2Sn=SnMe2, 16a), in agreement with earlier work. In contrast, the spectrum of the dimer formed from SnPh2 exhibits strong absorptions in the 280-380 nm range and a very weak absorption at 650 nm, on the basis of which it is assigned to phenyl(triphenylstannyl)stannylene (17b). The calculations suggest that 17b is formed via ultrafast rearrangement of a novel phenyl-bridged stannylidenestannylene intermediate (20), which can be formed either directly by "endo" dimerization of SnPh2 or by isomerization of the "exo" dimer, tetraphenyldistannene (16b); the predicted barriers for these rearrangements are consistent with the experimental finding that the observed product is formed at close to the diffusion-controlled rate. Absolute rate and equilibrium constants are reported for the reactions of SnMe2 and SnPh2 with Me2SnCl2 and methanol (MeOH), respectively, in hexanes at 25 °C.
- Duffy, Ian R.,Leigh, William J.
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p. 5029 - 5044
(2015/11/09)
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- Platinum-catalyzed phenyl and methyl group transfer from tin to iridium: Evidence for an autocatalytic reaction pathway with an unusual preference for methyl transfer
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Platinum complexes have been found to catalyze the transfer of σ-bound ligands to the Ir center in Cp*(PMe3)IrCl2 (Cp* = η5-C5Me5) from Bu3SnPh and PhxSnMe
- Smith, Stuart E.,Sasaki, Jennifer M.,Bergman, Robert G.,Mondloch, Joseph E.,Finke, Richard G.
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p. 1839 - 1841
(2008/09/17)
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- Haloalkylation process
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A process for the haloalkylation of certain tin, phosphorus and germanium halides is disclosed. The process is carried out typically in a halocarbon solvent at temperatures of less than 0° C. using as the haloalkylating reagent an admixture of a haloalkyl halide and tris(lower alkylamino)phosphine.
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- ORIGINE DE L'ETAIN FORME DURANT LES ELECTROLYSES DU DICHLORURE DE METHYLPHENYLETAIN
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Studies of electroreduction of methylphenyltin dichloride and dihydride enabled us to follow the formation of bis(chloromethylphenyltin).This dimer decays rapidly in the solid state.Migration of a phenyl group and disproportionation of the resulting chloromethyltin derivative initiated the formation of amalgamated tin and trisubstituted organotin compounds during electrolysis of the dichloride.
- Engel, Michele,Devaud, Marguerite
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