在重要的化学反应中具有高活性和选择性的纳米结构和可重复使用的 3d 金属催化剂是非常需要的。在这里,开发了一种钴催化剂,用于通过还原胺化反应合成伯胺,使用氢气作为还原剂,易处理的氨水溶解在水中,作为氮源。催化剂在非常温和的条件下运行(1.5 mol% 催化剂负载,50 °C 和 10 bar H 2压力)并优于市售的贵金属催化剂(Pd、Pt、Ru、Rh、Ir)。观察到广泛的范围和非常好的官能团耐受性。高活性的关键似乎是使用的载体:一种 N 掺杂的无定形碳材料,具有小的和乱层无序的石墨域,它是微孔的,具有双峰尺寸分布,并且在孔中具有基本的 NH 官能团。
Chiral Brønsted Acids Catalyze Asymmetric Additions to Substrates that Are Already Protonated: Highly Enantioselective Disulfonimide-Catalyzed Hantzsch Ester Reductions of NH–Imine Hydrochloride Salts
作者:Benjamin List、Vijay N. Wakchaure、Carla Obradors
DOI:10.1055/s-0040-1706413
日期:2020.10
are frequently used substrates in asymmetric Bronsted acid catalysis, their corresponding salts are generally considered unsuitable reaction partners. Such processes are challenging because they require the successful competition of a catalytic amount of a chiral anion with a stoichiometric amount of an achiral one. We now show that enantiopure disulfonimides enable the asymmetric reduction of N–H imine
[EN] CANNABINOID RECEPTOR TYPE 2 (CB2) MODULATORS AND USES THEREOF<br/>[FR] MODULATEURS DE RÉCEPTEUR CANNABINOÏDE DE TYPE 2 (CB2) ET LEURS UTILISATIONS