Co‐Catalyzed Synthesis of Primary Amines via Reductive Amination employing Hydrogen under very mild Conditions
作者:Matthias Elfinger、Timon Schönauer、Sabrina L. J. Thomä、Robert Stäglich、Markus Drechsler、Mirijam Zobel、Jürgen Senker、Rhett Kempe
DOI:10.1002/cssc.202100553
日期:2021.6.8
Nanostructured and reusable 3d-metal catalysts that operate with high activity and selectivity in important chemical reactions are highly desirable. Here, a cobalt catalyst was developed for the synthesis of primary amines via reductiveamination employing hydrogen as the reducing agent and easy-to-handle ammonia, dissolved in water, as the nitrogen source. The catalyst operates under very mild conditions
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
coordinatively unsaturated Co–Co active sites, which serve as a new class of air-stable, highly active, and reusable heterogeneous catalysts for the reductive amination of carbonyl compounds. The Co2P NR catalyst showed high activity for the transformation of a broad range of carbonyl compounds to their corresponding primary amines using an aqueous ammonia solution or ammonium acetate as a green amination
用于有机合成的金属磷化物催化剂的开发仍处于早期阶段。在此,我们报告了含有配位不饱和 Co-Co 活性位点的单晶磷化钴纳米棒 (Co 2 P NRs)的成功合成,其作为一类新型的空气稳定、高活性和可重复使用的非均相催化剂用于还原反应。羰基化合物的胺化。Co 2 P NR 催化剂在使用氨水溶液或乙酸铵作为绿色胺化试剂在 1 巴的 H 2压力下将范围广泛的羰基化合物转化为其相应的伯胺方面表现出高活性;这些情况比以前报道的要温和得多。Co 2的空气稳定性和高活性P NRs 值得注意,因为传统的 Co 催化剂对空气敏感(自燃)并且在温和条件下没有显示出这种转化的活性。因此,P 合金化对于用于有机合成的纳米工程空气稳定和高活性非贵金属催化剂具有相当重要的意义。
Phosphorescent materials
申请人:Universal Display Corporation
公开号:US10084143B2
公开(公告)日:2018-09-25
A compound selected from
is provided. An organic light emitting device including an anode, cathode, and organic layer disposed between the anode and cathode, including one of the compounds is also provided.