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。
Design and synthesis of ruthenium bipyridine catalyst: An approach towards low-cost hydroxylation of arenes and heteroarenes
作者:Sanchari Shome、Surya Prakash Singh
DOI:10.1016/j.tetlet.2017.08.037
日期:2017.9
Two new ruthenium bipyridine complexes were designed and synthesized for intermolecular Csp2-H hydroxylation. An environmentally begin and inexpensive oxidant was employed as an oxygen source thereby enhancing its applicability and resulting in the remarkable increase of yield. In the catalytic process a ruthenium (IV) cationic complex is formed which enables the regioselective CO bonds formation and
Regioselective synthesis of 2-(2-hydroxyaryl)pyridines from the reactions of benzynes with pyridine N-oxides
作者:Balagopal S. Shaibu、Rahul Kisan Kawade、Rai-Shung Liu
DOI:10.1039/c2ob26130h
日期:——
By modifying the conditions from those in Larock's reported synthesis of 3-(2-hydroxyaryl)pyridines from benzynes, and pyridine N-oxides, we altered the regioselectivity of the reaction toward an efficient synthesis of 2-substituted pyridines. The presence of ethyl propiolate altered the regioselectivity to afford 3-substituted pyridine products instead. We conducted appropriate control experiments
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
OLED DEVICE WITH CYCLOBUTENE ELECTRON INJECTION MATERIALS
申请人:Begley William J.
公开号:US20100141122A1
公开(公告)日:2010-06-10
An OLED device including a cathode, an anode, and having therebetween a light-emitting layer and further comprising a first layer between the light-emitting layer and the cathode containing a cyclobutene compound comprising a cyclobutene nucleus substituted in the 1-position with a five- or six-membered heteroaromatic ring group containing at least one trivalent nitrogen atom; substituted in the 2-position with an aromatic ring group; and substituted with a first methylene group in the 3-position and a second methylene group in the 4-position, provided said first and second methylene groups are further disubstituted in the 1′,1′-positions and the 1″,1″-positions with independently selected aromatic groups.