烯烃的氢化硅烷化是合成有机硅化合物的最重要方法之一。除了铂催化的氢化硅烷化,甲硅烷基自由基加成反应作为经济反应是值得注意的。通过在光催化条件下使用2-甲硅烷基化的二氢喹唑啉酮衍生物,开发了一种高效且广泛适用的甲硅烷基自由基加成反应。缺电子的烯烃和苯乙烯衍生物进行氢化硅烷化,以高产率得到加成产物。机理研究表明,光催化剂不是作为光氧化还原催化剂,而是作为能量转移催化剂。DFT计算表明,2-甲硅烷基化的二氢喹唑啉酮衍生物的三重激发态通过碳-硅键的均裂释放了甲硅烷基自由基,接着是氢原子转移途径,不是氧化还原途径。
The hydrosilylation of alkenes is one of the most important methods for the synthesis of organosilicon compounds. In addition to the platinum-catalyzed hydrosilylation, silyl radical addition reactions are notable as economic reactions. An efficient and widely applicable silyl radical addition reaction was developed by using 2-silylated dihydroquinazolinone derivatives under photocatalytic conditions. Electron-deficient alkenes and styrene derivatives underwent hydrosilylation to give addition products in good to high yields. Mechanistic studies indicated that the photocatalyst functioned not as a photoredox catalyst but as an energy transfer catalyst. DFT calculations clarified that the triplet excited state of 2-silylated dihydroquinazolinone derivatives released a silyl radical through the homolytic cleavage of a carbon-silicon bond, and this was followed by the hydrogen atom transfer pathway, not the redox pathway.