Self‐Encapsulation of Homogeneous Catalyst Species into Polymer Gel Leading to a Facile and Efficient Separation System of Amine Products in the Ru‐Catalyzed Reduction of Carboxamides with Polymethylhydrosiloxane (PMHS).

Abstract

PMHS). -A new concept for efficient Ru-catalyzed reduction of carboxamides with polymethylhydrosiloxane uses the microcapsulation technique for removal of the catalyst species from the product. The latter is self-encapsulated into the insoluble polymer during the reduction. The ruthenium-containing silicon resin can easily be separated, recovered and reused. -(MOTOYAMA, Y.; MITSUI, K.; ISHIDA, T.; NAGASHIMA*, H.; J. Am. Chem. Soc. 127 (2005) 38, 13150-13151; Inst. Mater. Chem. Eng., Kyushu Univ., Kasuga 816, Japan; Eng.) -Bartels 05-065

Highly Recyclable Fluoride for Enhanced Cascade Hydrosilylation–Cyclization of Levulinates to γ-Valerolactone at Low Temperatures

“…It was worth noting that the weight of the recovered solid catalyst was increased to about 90 mg in the sixth run due to the formation of insoluble PMHS-derived resin. 21 Figure S4 presents the photos of the KF-catalyzed reaction mixtures before and after reactions as well as the recovered silicone resin containing F species. The increased catalyst weight, surface area, and pore size could be ascribed to the porous resin in situ formed by encapsulation of the fluoride species with PMHS, which are in agreement with previous reports that claimed the cross-linking of the silicon−polymer to soak up homogeneous species.…”

An efficient catalytic and solvent‐free method for the synthesis of mono‐organofunctionalized polymethylhydrosiloxane derivatives

“…As summarized in Table 3, the reaction conversion showed a gradual increase with reactions with silicone oil with higher hydrogen content, and the time for the reaction to reach its endpoint gradually decreased. However, lower conversion rates were generally achieved from reactions performed with silicone oils that had higher hydrogen content, such as PMHS 5 and PMHS 6 . As previously stated, we compared solvent-based and solvent-free systems for each reaction separately.…”

“…[1][2][3] Polymethylhydrosiloxane (PMHS) is one of the most widely studied silicones due to its excellent physical and chemical properties, such as low surface tension, low glass transition temperature, high permeability (N 2 and O 2 ), low temperature resistance, favorable flow film formation behavior, excellent viscoelasticity, and so forth. [4][5][6] Due to its availability in explicit microstructures, PMHS is a promising starting material for many synthetic reactions. [7][8][9][10] Furthermore, the equally distributed Si H bonds in PMHS may be considered as chemical handles to which organic groups can be catalytically attached in order to produce hybrid materials that cannot be obtained via the physical mixing of distinct phases.…”

Hydrophilic Polysiloxane Microspheres and Ceramic SiOC Microspheres Derived from Them

“…Polysiloxane microspheres are commonly used in medicine and biology for drug delivery systems [7,8], biological probes and biosensors [9], carrier of proteins [10], supports in enzymatic catalysis [11], and carriers of biocides [12]. They are exploited in the catalysis of various chemical reactions [13,14] and as components of composite materials [15]. The synthesis and use of polysiloxane microspheres of various morphologies and chemical structures have been the subject of extensive research devoted to polysiloxane core-shell [16,17], hollowed [18,19] and porous [17] microspheres as well as to beads containing other materials dispersed or dissolved in polysiloxane matrixes [20,21].…”