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。
Metallaphotoredox-Mediated C<sub>sp2</sub>–H Hydroxylation of Arenes under Aerobic Conditions
作者:Sk. Sheriff Shah、Amrita Paul、Manoranjan Bera、Yarra Venkatesh、N. D. Pradeep Singh
DOI:10.1021/acs.orglett.8b01973
日期:2018.9.21
The direct hydroxylation of 2-arylpyridines and 2-arylbenzothiazoles via the merger of organic photoredox and metal catalysis is reported where 4CzIPN is used as the visible-light photocatalyst and Pd(OAc)2 as the metal catalyst. This method has been employed to synthesize organic molecules exhibiting excited-stateintramolecularprotontransfer properties for generating tunable luminescence responses
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
Photo-Induced <i>ortho</i>-C–H Borylation of Arenes through In Situ Generation of Rhodium(II) Ate Complexes
作者:Jin Tanaka、Yuki Nagashima、Antônio Junio Araujo Dias、Ken Tanaka
DOI:10.1021/jacs.1c05859
日期:2021.8.4
Photoinduced in situ “oxidation” of half-sandwich metal complexes to “high-valent” cationic metal complexes has been used to accelerate catalytic reactions. Here, we report the unprecedented photoinduced in situ “reduction” of half-sandwich metal [Rh(III)] complexes to “low-valent” anionic metal [Rh(II)] ate complexes, which facilitate ligand exchange with electron-deficient elements (diboron). This