Cerium photocatalyzed dehydrogenative lactonization of 2-arylbenzoic acids
作者:Ketan Wadekar、Suraj Aswale、Veera Reddy Yatham
DOI:10.1039/c9ob02676b
日期:——
The first cerium photocatalyzed dehydrogenative lactonization of 2-arylbenzoic acids has been developed. This operationally simple protocol allows rapid access to synthetically useful coumarins on gram scale by employing CeCl3 as a photocatalyst and O2 as a terminal oxidant. Overall, this delivers an economical and environmentally amiable entry to diversely substituted coumarins, important structural
A practical, electrochemical method is developed for the direct dehydrogenative lactonization of C(sp2/sp3)–H bonds under external oxidant- and metal-free conditions, delivering diverse lactones, including coumarin derivatives with excellent regioselectivity. The scalable nature of this newly developed electrochemical process was demonstrated on a 40 g scale following an operationally simple protocol
Organocatalytic Electrochemical C–H Lactonization of Aromatic Carboxylic Acids
作者:Sanzhong Luo、Longji Li、Qi Yang、Zongbin Jia
DOI:10.1055/s-0036-1591558
日期:2018.8
Radical Methods and their Strategic Applications in Synthesis Abstract An electrochemical strategy has been developed for radical arene carbon–oxygen bond formation. This reaction utilizes DDQ as a redox mediator, with inexpensive glassy carbon electrodes to facilitate an intramolecular lactonization of biphenyl-2-carboxylic acid derivatives via aromatic carboxyl radical substitution to give 6H-be
§这些作者同等贡献。 作为特别主题“现代自由基方法及其在合成中的战略应用”的一部分发布 抽象的 已经开发出一种用于自由基芳烃碳-氧键形成的电化学策略。该反应利用DDQ作为氧化还原介体,并具有廉价的玻璃碳电极,以通过芳族羧基自由基取代促进联苯-2-羧酸衍生物的分子内内酯化,得到6 H-苯并[ c ] chromen-6-one。 已经开发出一种用于自由基芳烃碳-氧键形成的电化学策略。该反应利用DDQ作为氧化还原介体,并具有廉价的玻璃碳电极,以通过芳族羧基自由基取代促进联苯-2-羧酸衍生物的分子内内酯化,得到6 H-苯并[ c ] chromen-6-one。
General and Practical Carboxyl-Group-Directed Remote CH Oxygenation Reactions of Arenes
作者:Yang Wang、Anton V. Gulevich、Vladimir Gevorgyan
DOI:10.1002/chem.201303511
日期:2013.11.18
Two methods for remote aromatic CHoxygenationreactions, have been developed. Method 1, the Cu‐catalyzed oxygenationreaction, is highly efficient for cyclization of electron‐neutral and electron‐rich biaryl carboxylic acids into 3,4‐benzocoumarins. Method 2, the K2S2O8‐mediated oxygenationreaction, is more general and practical for cyclization of substrates with electron‐donating and ‐withdrawing
已经开发了两种用于远程芳族 C H 氧化反应的方法。方法 1,即 Cu 催化的氧化反应,对于将电子中性和富电子的联芳基羧酸环化为 3,4-苯香豆素非常有效。方法 2,K 2 S 2 O 8介导的氧化反应,对于具有给电子和吸电子基团的底物的环化更为通用和实用(见方案)。