Abstract A heterogeneous metal-loaded titanium oxide photocatalyst provided an efficient route to bring out direct dehydrogenative cross-coupling between toluene and acetone without consuming any additional oxidizing agent. The nature of the metal nanoparticle cocatalyst deposited on TiO 2 photocatalyst dictated the product selectivity for the cross-coupling. Pd nanoparticles on TiO 2 photocatalyst allowed a C–C bond formation between the aromatic ring of toluene and acetone to give 1-( o -tolyl)propan-2-one ( 1a1 ) with high regioselectivity, while Pt nanoparticles on TiO 2 photocatalyst promoted the cross-coupling between the methyl group of toluene and acetone to give 4-phenylbutan-2-one ( 1b ) as the acetonylated product. These results demonstrated that the selection of the metal cocatalyst on TiO 2 photocatalyst could determine which C–H bonds in toluene, aromatic or aliphatic, can react with acetone. Two kinds of reaction mechanisms were proposed for the photocatalytic dehydrogenative cross-coupling reaction, depending on the property of the metal nanoparticles, i.e., only Pd nanoparticles can catalyze the reaction between aromatic ring and the acetonyl radical species. Graphic Abstract

中文翻译：

---

金属助催化剂通过与丙酮脱氢交叉偶联指导甲苯光催化乙酰化

摘要 负载多相金属的二氧化钛光催化剂提供了一种在不消耗任何额外氧化剂的情况下实现甲苯和丙酮之间直接脱氢交叉偶联的有效途径。沉积在 TiO 2 光催化剂上的金属纳米颗粒助催化剂的性质决定了交叉偶联的产物选择性。TiO 2 光催化剂上的 Pd 纳米颗粒允许在甲苯和丙酮的芳环之间形成 C-C 键，得到具有高区域选择性的 1-(o-tolyl)propan-2-one (1a1)，而 TiO 2 光催化剂上的 Pt 纳米颗粒促进甲苯的甲基和丙酮之间的交叉偶联得到 4-苯基丁-2-酮 (1b) 作为乙酰化产物。这些结果表明，选择 TiO 2 光催化剂上的金属助催化剂可以确定甲苯中的哪些 C-H 键，芳香族或脂肪族，可以与丙酮反应。根据金属纳米粒子的性质，提出了两种光催化脱氢交叉偶联反应的反应机制，即只有Pd纳米粒子才能催化芳环与丙酮自由基物种之间的反应。图形摘要