A versatile rhodium(III) catalyst for direct acyloxylation of aryl and alkenyl C-H bonds with carboxylic acids was written by Chen, Changjun;Pan, Yixiao;Zhao, Haoqiang;Xu, Xin;Xu, Jianbin;Zhang, Zongyao;Xi, Siqi;Xu, Lijin;Li, Huanrong. And the article was included in Organic Chemistry Frontiers in 2018.Reference of 4783-68-0 This article mentions the following:
Rh(III)-catalyzed highly regioselective direct acyloxylation of sp2 C-H bonds with carboxylic acids was developed. The catalytic system consisting of a cationic Rh(III) complex and a silver oxidant allowed a variety of arenes and alkenes bearing different directing groups (not limited to strongly coordinating N-heterocyclic directing groups) to undergo efficient acyloxylation with a broad range of readily available alkyl, alkenyl and aryl carboxylic acids, and a number of valuable functional groups in both coupling partners were well tolerated in the reaction regardless of their electronic properties and positions. This method provided a straightforward and convenient access to various valuable acyloxylated products. Furthermore, the synthetic utility of this protocol was demonstrated by the later-stage functionalization and modification of biol. active compounds Mechanistic studies revealed the involvement of five-membered rhodacycles as key intermediates. In the experiment, the researchers used many compounds, for example, 2-Phenoxypyridine (cas: 4783-68-0Reference of 4783-68-0).
2-Phenoxypyridine (cas: 4783-68-0) belongs to pyridine derivatives. The ring atoms in the pyridine molecule are sp2-hybridized. The nitrogen is involved in the π-bonding aromatic system using its unhybridized p orbital. The lone pair is in an sp2 orbital, projecting outward from the ring in the same plane as the σ bonds. Halopyridines are particularly attractive synthetic building blocks in a variety of cross-coupling methods, including the Suzuki-Miyaura cross-coupling reaction.Reference of 4783-68-0