Department of Drug Science and Technology and NIS Interdepartmental Centre, University of Turin, Via Pietro Giuria 9, 10125, Turin, Italy.
Department of Chemistry, University of Milan, Via Golgi 19 - Corpo, A, 20133, Milan, Italy.
Chempluschem. 2023 Mar;88(3):e202300017. doi: 10.1002/cplu.202300017.
Microwave (MW)-assisted reductive aminations of aldehydes and ketones were carried out in the presence of commercial and homemade heterogeneous Rh-based catalysts. Ultrasound (US) was used to improve dispersion and stability of metal nanoparticles, while commercial activated carbon and carbon nanofibers were used as supports. Moreover, various bio-derived molecules were selected as substrates, and aqueous ammonia was used as a cheap and non-toxic reagent. MW combined with heterogeneous Rh catalysts gave a 98.2 % yield in benzylamine at 80 °C with 10 bar H for 1 h; and a 43.3 % yield in phenylethylamine at 80 °C and 5 bar H for 2 h. Carbon nanofibers proved to be a better support for the metal active phase than simple activated carbon, since a limited yield in benzylamine (10.6 %) but a high selectivity for the reductive amination of ketones was obtained. Thus, raspberry ketone was converted to raspberry amine in a 63.0 % yield.
在商业和自制的均相 Rh 基催化剂存在下，进行了微波（MW）辅助的醛和酮的还原胺化反应。超声（US）用于改善金属纳米粒子的分散性和稳定性，而商业活性炭和碳纳米纤维则用作载体。此外，选择了各种生物衍生的分子作为底物，并用廉价且无毒的氨水溶液作为试剂。MW 与均相 Rh 催化剂结合，在 80°C、10 bar H 下反应 1 小时，可得到 98.2%的苄胺产率；在 80°C、5 bar H 下反应 2 小时，可得到 43.3%的苯乙胺产率。碳纳米纤维被证明是金属活性相的更好载体，因为得到的苄胺产率有限（10.6%），但酮的还原胺化具有很高的选择性。因此，覆盆子酮转化为覆盆子胺的产率为 63.0%。
