The development of nanoparticles-based heterogeneous catalysts continues to be of scientific and industrial interest for the advancement of sustainable chemical processes. Notably, up-scaling the production of catalysts to sustain unique structural features, activities and selectivities is highly important and remains challenging. Herein, we report the expedient synthesis of Pd-nanoparticles as amination catalysts by the reduction of simple palladium salt on commercial silica using molecular hydrogen. The resulting Pd-nanoparticles constitute stable and reusable catalysts for the synthesis of various N-alkyl amines using borrowing hydrogen technology without the use of any base or additive. By applying this Pd-based catalyst, functionalized and structurally diverse N-alkylated amines as well as some selected drug molecules were synthesized in good to excellent yields. Practical and synthetic utility of this Pd-based amination protocol has been demonstrated by upscaling catalyst preparation and amination reactions to several grams-scales as well as recycling of catalyst. Noteworthy, this Pd-catalyst preparation has been up-scaled to kilogram scale and catalysts prepared in both small (1 g) and large-scale (kg) exhibited similar structural features and activity.

基于纳米颗粒的非均相催化剂的发展对于可持续化学过程的发展继续具有科学和工业兴趣。值得注意的是，扩大催化剂的生产以维持独特的结构特征，活性和选择性非常重要，并且仍然具有挑战性。在本文中，我们报告了通过使用分子氢在商业二氧化硅上还原简单的钯盐，可以方便地合成Pd-纳米颗粒作为胺化催化剂。所得的Pd-纳米粒子构成稳定且可重复使用的催化剂，用于使用借用氢技术合成各种N-烷基胺，而无需使用任何碱或添加剂。通过使用这种Pd基催化剂，官能化和结构多样的N-烷基化胺以及一些选定的药物分子以良好至极好的收率合成。通过将催化剂的制备和胺化反应扩大到几克规模以及催化剂的再循环，已经证明了这种基于Pd的胺化方案的实用性和合成性。值得注意的是，这种Pd催化剂的制备规模已扩大到千克规模，以小量（1克）和大规模（kg）制备的催化剂均显示出相似的结构特征和活性。