In this work, the chiral modifier c

In this work, the chiral modifier cinchonidine (CD) was used to modify the Pt nanoparticles limited to the carbon nanotube lumen, and the catalytic system was found to have active TOF (turnover frequency) in the chiral hydrogenation reaction of α-ketoesters. Up to 1.2 × 10 5 h-1, the chiral selectivity reaches 96% ee, the catalytic activity and chiral selectivity of Pt nanoparticles in the lumen of carbon nanotubes is significantly higher than that of Pt nanoparticles outside the lumen of carbon nanotubes (TOF: 1.5 × 10 4 h-1, 75% ee), which is also much higher than the performance of the best reported Pt / Al3O2 catalyst (TOF: 1.0 × 10 4 h-1, 90% ee). A preliminary study found that the carbon nanotube lumen showed strong enrichment with the chiral modifier CD and substrate, which may be one of the main reasons for the significant increase in chiral catalytic reaction activity and chiral selectivity in carbon nanotubes. Recently in the German Applied Chemistry, the research group of Academician Li Can reported a Pt catalyst supported on carbon nanotubes, which showed excellent heterogeneous chiral hydrogenation activity. By comparing the catalytic activity of two Pt catalysts with different loading positions (ie, outside and inside the tube), the authors say that the confinement effect of carbon nanotubes is reflected in the carbon nanotube lumen showing excellent enrichment with chiral modifiers and substrates Effect, which may lead to a significant increase in chiral catalytic reaction activity and chiral selectivity in carbon nanotubes. The core point here is the confinement effect of carbon nanotubes. Filling the active components into a tank, in such a microreactor, it is possible to achieve micro-checks and balances of the catalytic reaction, thereby producing unexpected effects.