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Hydrosilylation of cinchonidine and 9-O-TMS-cinchonidine with triethoxysilane: application of 11-(triethoxysilyl)-10,11-dihydrocinchonidine as a chiral modifier in the enantioselective hydrogenation of 1-phenylpropane-1,2-dione

“…including cinchonidine, with triethoxysilane in the presence of the Speier catalyst and the subsequent "one-pot" immobilization on a silica surface by sol-gel technology. 5 However, reaction intermediates were not characterized and identification of the immobilized compounds was based exclusively on a combination of IR, UV and solid state 13 C NMR methods. This prompted us to report our independent studies on the hydrosilylation of (Ϫ)-cinchonidine (1) and 9-O-(trimethylsilyl)cinchonidine (2) with triethoxysilane in the presence of hydrogen hexachloroplatinate (Speier catalyst) or platinum divinyltetramethyldisiloxane (Karstedt catalyst).…”

“…Tertykh and coworkers reported the corresponding hydrosilylation reaction using a propan-2-ol solution of the Speier catalyst and equimolar amounts of cinchonidine and triethoxysilane in a 10 : 0.7 propan-2-ol-acetic acid solvent mixture. 5 However, the product was neither isolated nor characterized and the yield of the hydrosilylation was not reported. During the initial stages of our investigation we carried out a similar reaction in the absence of acetic acid.…”

Cinchona Alkaloids Tethered on Porous Silica as Enantioselective Heterogeneous Catalysts

“…Analog tethering chemistry has already been used successfully in the making of stationary chiral phases for chromatographic applications [19,20], and preliminary work has been reported on the used of tethered cinchona to promote Michael addition reactions [21,22]. A couple of studies on similar systems have also been reported in the past which provide limited characterization information on the tethering chemistry [23][24][25][26].…”

Synthesis of an MCM-41-supported mercapto rhodium complex and its catalytic behavior in the hydrosilylation of olefins with triethoxysilane

“…The hydrosilylation of olefins is one of the most important Si-C bond formation reactions in organosilicon chemistry [1][2][3][4]. Polymer-supported transition metal complex catalysts are currently attracting great interest because they have the advantages of both homogeneous and heterogeneous catalyzed processes [5,6].…”