78764-88-2Relevant academic research and scientific papers
Tin-Catalyzed Synthesis of 5-Substituted 1H-Tetrazoles from Nitriles: Homogeneous and Heterogeneous Procedures
Chrétien, Jean-Mathieu,Kerric, Gaelle,Zammattio, Fran?oise,Galland, Nicolas,Paris, Michael,Quintard, Jean-Paul,Le Grognec, Erwan
supporting information, p. 747 - 757 (2019/01/04)
The preparation of 5-substituted 1H-tetrazoles was efficiently achieved by reaction of trimethylsilylazide with nitriles using a triorganotin alkoxide precatalyst. The reaction mechanism was first investigated using a homogeneous tributyltin derivative and was explored through experimental investigations and DFT calculations. A heterogeneous version was then developed using a polymer-supported organotin alkoxide and afforded an efficient method for the preparation of tetrazoles in high yields with an easy work-up and a residual tin concentration in the desired products compatible for pharmaceutical applications (less than 10 ppm). (Figure presented.).
First gas-phase detection of dimethylstannylene and time-resolved study of some of its reactions
Becerra, Rosa,Boganov, Sergey E.,Egorov, Mikhail P.,Faustov, Valery I.,Krylova, Irina V.,Nefedov, Oleg M.,Walsh, Robin
, p. 7555 - 7562 (2007/10/03)
Using a laser flash photolysis/laser probe technique, we report the observation of strong absorption signals in the wavelength region 450-520 nm (highest intensity at 514.5 nm) from four potential precursors of dimethylstannylene, SnMe2, subjected to 193 nm UV pulses. From GC analyses of the gaseous products, combined with quantum chemical excited state CIS and TD calculations, we can attribute these absorptions largely to SnMe2, with SnMe4 as the cleanest source of the species. Kinetic studies have been carried out by time-resolved monitoring of SnMe2. Rate constants have been measured for its reactions with 1,3-C4H6, MeC, CMe, MeOH, 1-C4H9Br, HCl, and SO2. No evidence could be found for reaction of SnMe2 with C2H4, C3H8, Me3SiH, GeH4, Me2GeH2, or N2O. Limits of less than 10-13 cm3 molecule-1 s-1 were set for the rate constants for these latter reactions. These measurements showed that SnMe2 does not insert readily into C-H, Si-H, Ge-H, C-C, Si-C, or Ge-C bonds. It is also unreactive with alkenes although not with dienes or alkynes. It is selectively reactive with lone pair donor molecules. The possible mechanisms of these reactions are discussed. These results represent the first visible absorption spectrum and rate constants for any organo-stannylene in the gas phase.
Reduction of Halosilanes by Organotin Hydrides
Wilt, James W.,Belmonte, Frank G.,Zieske, Paul A.
, p. 5665 - 5675 (2007/10/02)
A study of the reduction of halosilanes with organotin hydrides is described.The free radical chain mechanism indicated by the results obtained parallels that known for the comparable reduction of haloalkanes, but the reactivity of α-haloalkanes is considerable enhanced.Mechanistic studies suggest that the polar nature of the halogen abstraction step in the radical chain sequence, which places incremental negative charge adjacent to silicon, is the principal reason for this enhanced reactivity.Structure-reactivity studies indicat the gem-dimethylsilyl function to be an electronic transmitter.The ρ values for reduction of aryldimethyl(chloromethyl)silanes and substituted benzyl chlorides by tri-n-butyltin hydride are essentially identical (+0.45).Reduction of (chloromethyl)trimethylsiulane with aryldimethyltin hydrides, conversely, yielded a ρ value of -1.61.The reduction produced racemic product from an optically active α-chlorosilane, the synthesis of which appears to the first reported.Other syntheses of variuos halosilanes of interest are also described.The title reduction is specific for carbon-halogen bonds.Silicon-halogen bonds are not affected, a distinction that should make the reduction synthetically useful.Because the increased reactivity of α-halosilanes in the reduction has thus been ascribed to a kinetic polar effect in a critical step of the mechanism, no compelling argument for special thermodynamic stability in α-silyl radicals themselves can be made.
METALLA IVb-PHOSPHOLANNES. I. Dimetalla-2,5 Phospholannes, Metalla-2 Diphospholannes-1,3 et Metalla-3 Diphospholannes-1,2
Andriamizaka, J. D.,Couret, C.,Escudie, J.,Satge, J.
, p. 265 - 278 (2007/10/02)
We present the synthesis of novel sila-, germa- and stanna-phospholanes: 2,5-dimetallaphospholanes, 2-metalla 1,3-diphospholanes and 3-metalla 1,2-diphospholanes.Preparation and characterization reactions of the first stable diphosphorus germylene are als
