Graduate School of Engineering Sciences, Institute for Materials Chemistry and Engineering, Kyushu University, Kasuga, Fukuoka 816-8580, Japan.
J Am Chem Soc. 2009 Oct 21;131(41):15032-40. doi: 10.1021/ja9055307.
The synergetic effect of two Si-H groups leads to efficient reduction of carboxamides to amines by platinum catalysts under mild conditions. The rate of the reaction is dependent on the distance of two Si-H groups; 1,1,3,3-tetramethyldisiloxane (TMDS) and 1,2-bis(dimethylsilyl)benzene are found to be an effective reducing reagent. The reduction of amides having other reducible functional groups such as NO(2), CO(2)R, CN, C horizontal lineC, Cl, and Br moieties proceeds with these groups remaining intact, providing a reliable method for the access to functionalized amine derivatives. The platinum-catalyzed reduction of amides with polymethylhydrosiloxane (PMHS) also proceeds under mild conditions. The reaction is accompanied by automatic removal of both platinum and silicon wastes as insoluble silicone resin, and the product is obtained by simple extraction. A mechanism involving double oxidative addition of TMDS to a platinum center is discussed.
两个 Si-H 基团的协同效应导致铂催化剂在温和条件下有效地将酰胺还原为胺。反应速率取决于两个 Si-H 基团的距离；发现 1,1,3,3-四甲基二硅氧烷（TMDS）和 1,2-双（二甲基硅基）苯是有效的还原剂。具有其他可还原官能团的酰胺的还原，如 NO(2)、CO(2)R、CN、C 水平 C、Cl 和 Br 部分，这些基团保持完整，为获得功能化胺衍生物提供了可靠的方法。多甲基氢硅氧烷（PMHS）催化的酰胺还原也在温和条件下进行。反应伴随着铂和硅废物自动去除，形成不溶性硅树脂，产物通过简单萃取获得。讨论了涉及 TMDS 对铂中心的双重氧化加成的机理。
