- Waste-free and efficient hydrosilylation of olefins
-
High purity silicone precursors can now be synthesized by hydrosilylation of solvent-free olefins catalyzed by a highly stable and active glass hybrid catalyst consisting of mesoporous organosilica microspheres doped with Pt nanoparticles. These findings open the door to the sustainable manufacture of silicone and a way to further reduce the amount of platinum in silicones, which are ubiquitous advanced polymers with multiple uses and applications.
- Pandarus, Valerica,Ciriminna, Rosaria,Gingras, Geneviève,Béland, Fran?ois,Kaliaguine, Serge,Pagliaro, Mario
-
p. 129 - 140
(2019/01/11)
-
- Nucleophile-assisted racemisations of halosilanes - kinetic studies
-
Kinetic studies have been carried out on the nucleophile-induced racemisation of PhMeCHSiMe2X, 2, X = triflate, Br or Cl.Thirteen nucleophiles were studied.The results are interpreted in terms of two competing mechanisms for racemisation: (a) nucleophile attack on a silane-nucleophile complex formed by displacement of the halide by the nucleophile, and (b) halide-halosilane exchange, with inversion of configuration.Solvent effects were examined, and kinetic orders in the nucleophile and in one case for the halosilane were determined.The order in added nucleophile varied between one and two, with strong nucleophiles in polar media.Anomalously high orders in nucleophile were observed in non-polar media and are ascribed to aggregation of the nucleophile.A kinetic analysis of the competing mechanisms was attempted, and was consistent with the experimental findings.In this particular series of reactions involving compounds with good leaving groups and relatively powerful nucleophiles there was no evidence for intermediates involving extracoordinate silicon. Keywords: Silicon; Racemisation; Mechanism
- Bassindale, Alan R.,Lau, Juliana C.-Y.,Taylor, Peter G.
-
-
- Nucleophile-assisted racemisation of halosilanes; an alternative pathway involving halide exchange
-
An NMR method using diastereotopic halosilanes, PhCH(Me)SiMe2X (X = Cl or Br) has been developed for studying nucleophile-assisted racemisations of halosilanes.A mechanism for racemisation involving halide exchange is proposed to account for the observati
- Bassindale, Alan R.,Lau, Juliana C.-Y.,Taylor, Peter G.
-
p. 213 - 224
(2007/10/02)
-
- LE COMPLEXE 2> CATALYSEUR HOMOGENE D'HYDROGENATION ET D'HYDROSILYLATION D'OLEFINES ET D'ALDEHYDES ET CETONES α,β-INSATURES
-
The chloro-bridged platinum(II) complex dichlorobis(2,4,6-trimethylpyridine)platinum was found to be an active catalyst for homogeneous hydrogenation and hydrosilylation of olefins and α,β-unsaturated aldehydes and ketones at room temperature and under atmospheric pressure.Hydrosilylation of terminal olefins can be achieved with dimethylphenylsilane and a catalyst/reactant ratio of 10-6/1.This complex is the first example of a platinum(II) compound containing pyridine ligands having good catalytic activity possibilities.
- Rumin, R.
-
p. 351 - 356
(2007/10/02)
-