Development of Metal-Encapsulating Silicone Gel Catalysts

本工作以聚甲基氢硅氧烷和1，5-己二烯为原料，通过硅氢化反应成功地将含烯基的联吡啶和手性双恶唑啉配体固定到聚硅氧烷凝胶中。这些配体包封凝胶有效地捕获Cu盐以在凝胶中产生催化活性物质。这些包封金属的有机硅凝胶可作为有效的可回收催化剂，用于α-卤代乙酰胺的原子转移自由基环化以及烯烃和重氮乙酸酯的不对称环丙烷化，而不会浸出金属物质。

In this work, we succeeded in immobilizing bipyridine and chiral bis(oxazoline) ligands bearing alkenyl moieties into the polysiloxane gels by hidrosilylation using polymethylhydrosiloxane and 1, 5-hexadiene. These ligand-encapsulating gels capture the Cu salts effectively to generate the catalytically active species in the gel. These metal-encapsulating silicone gels act as efficient recyclable catalysts for atom-transfer radical cyclization of alfa-halogenated acetoamides and asymmetric cyclopropanation of alkenes and diazoacetates without leaching of the metallic species.