Polycarbosilane‐supported titanium(IV) catalyst for Knoevenagel condensation reaction

Abstract

Polycarbosilane (PCS) was synthesized by the polycondensation of trichloromethylsilane and trimethoxyvinylsilane in the presence of sodium metal. PCS has a highly crosslinked structure, high ceramic yield and high surface area. Titanium metal ion was attached to the polycarbosilane and its catalytic activity was investigated. The Knoevenagel condensation reaction catalysed by titanium-incorporated polycarbosilane is reported. The titanium-incorporated PCS catalysed the reaction well and with a diverse set of substrates the reaction proceeded with good yield. PCS-supported transition metal catalysts have been prepared for the first time and used successfully in the Knoevenagel condensation reaction.

Dendrimer functionalized polysilane: An efficient and recyclable organocatalyst

“…However, to the best of our knowledge, there are no reports on the use of polysilane as a support for dendrimer in heterogeneous catalysis. The PS‐PPIG3 dendrimer showed higher activity in comparison with the earlier reports . In this article, we describe the first example of the PPI dendrimer grafted polysilane catalyst; its preparation and application in Knoevenagel condensation reaction.…”

“…In this article, we describe the first example of the PPI dendrimer grafted polysilane catalyst; its preparation and application in Knoevenagel condensation reaction. In a previous report, in which the highly cross‐linked nature of the polymer support made the catalytic centre less accessible for the active participation in the reaction and took more time for the completion of the reaction.…”

Palladium(II) supported on polycarbosilane: Application as reusable catalyst for Heck reaction

“…It is not hard to envision a variety of potential applications that are opening up for these polymers in areas such as nanotechnology [1], surface science, catalysis [2][3][4][5][6], liquid crystals [7][8][9], new ceramic materials [10][11][12][13][14], organic-inorganic hybrids etc. PCS, which contains both Si and C in their back bone structure, have been of particular importance as precursor to SiC [15][16][17][18][19][20][21].…”

“…A reasonable ceramic yield is obtained after sufficient crosslinking which increases the softening temperature and decreases the solubility. The highly crosslinked nature of the PCS provides scope for high surface area for the polymer [4,5]. High surface area is one of the main criteria * Corresponding author.…”

“…Silica is a favorable solid support, but if silica is used directly, the main problem of these catalytic systems seems to be the metal leaching from the support during the reaction even though they adsorb back to the support after the completion of the reaction [27]. Polymer supported transition metal ions have significant role as catalysts in various organic reactions [4,5,29,30]. The metal ions are attached to the polymer support through a chemical bond.…”