Rad transition: The combination of transition‐metal‐catalyzed CHactivation and a NHPI‐initiated radical process is essential for the title transformation. The neutral conditions and the ideal oxidant, molecular oxygen, make this hydroxylation environmentally friendly and practical. NHPI=N‐hydroxyphthalimide.
Herein we present a Pd-catalyzeddirectC–H hydroxylation of 2-arylpyridines using molecular oxygen (O2) as the sole oxidant. The key aspects of the method include: (a) the activation of molecular oxygen with a nontoxic and inexpensive aldehyde; (b) an efficient association of the in situ-generated acyl peroxo radical with palladium catalysis; and (c) convenient operating conditions. On the basis of
本文中,我们介绍了使用分子氧(O 2)作为唯一氧化剂的Pd催化2-芳基吡啶的直接C–H羟基化反应。该方法的关键方面包括:(a)用无毒且廉价的醛活化分子氧;(b)原位产生的酰基过氧自由基与钯催化的有效结合;(c)方便的操作条件。基于一系列对照实验中获得的结果,涉及Pd II / Pd IV催化循环的转化。此外,该方法可容易地以良好的分离产率获得广泛范围的取代的2-(吡啶-2-基)苯酚。
AROMATIC COMPOUNDS
申请人:Merck Patent GmbH
公开号:US20200039903A1
公开(公告)日:2020-02-06
The present invention relates to aromatic compounds suitable for preparation of asymmetric polydentate ligands. The present invention further describes a process for preparing asymmetric polydentate ligands and metal complexes comprising these ligands which are suitable for use as emitters in organic electroluminescent devices.
Direct functionalization of the ubiquitous CHbond is receiving much attention because complex structures can be formed from simple precursors. This paper reports a useful method for the direct hydroxylation of 2‐phenylpyridines using palladium(II) chloride and aqueous hydrogen peroxide. In this method, hydrogen peroxide, which has high atom efficiency, is employed as the oxidant and phenol derivatives
PHOSPHORESCENT EXCIMERS WITH PREFERRED MOLECULAR ORIENTATION AS MONOCHROMATIC EMITTERS FOR DISPLAY AND LIGHTING APPLICATIONS
申请人:Li Jian
公开号:US20210193936A1
公开(公告)日:2021-06-24
An organic light emitting diode having a substrate, a first electrode, a hole transporting layer proximate the first electrode, a second electrode, an electron transporting layer proximate the second electrode, and an emissive layer between the hole transporting layer and the electron transporting layer. The emissive layer includes a square planar tetradentate platinum or palladium complex, and excimers formed by two or more of the complexes are aligned such that emitting dipoles of the excimers are substantially parallel to a surface of the substrate.