Cs2CO3‐Promoted C−O Coupling Protocol Enables Solventless (Hetero)aryl Ether Synthesis under Air Atmosphere

• Published in: Chemistry, an Asian journal an Asian journal, 2022-03, Vol.17 (6), p.n/a
• Main Authors: Jiang, Bowen, Chen, Cheng, Fan, Guang‐Gao, Sang, Wei, Cheng, Hua, Zhang, Rui, Yuan, Ye, Li, Qi‐Zhong, Verpoort, Francis
• Format: Article
• Language: English
• Subjects: air atmosphere; Alcohols; Aromatic compounds; Cesium carbonate (Cs2CO3); Chemical reactions; Chemistry; Cross coupling; C−O coupling; Density functional theory; density functional theory (DFT); Reagents; solvent-free; Synthesis; transition-metal-free
• ISSN: 1861-4728; 1861-471X
• DOI: 10.1002/asia.202101370

In this work, a Cs2CO3‐promoted synthetic approach was identified for (hetero)aryl ether synthesis via the C−O coupling of various (hetero)aryl chlorides and alcohols/phenol. To our delight, the reactions could be carried out under transition‐metal‐free and solvent‐free conditions. Moreover, analytical‐grade reagents and air atmosphere were readily tolerated. To showcase the practical usefulness of the present protocol, the assembly of a bioactive molecule was facilely realized and the gram‐scale production of selected ether products was also efficiently accomplished. In addition, density functional theory (DFT) studies, along with a few mechanistic experiments, were conducted to elucidate a proposed reaction pathway and rationalize the pivotal role of Cs2CO3 in promoting this process. Hopefully, this work could provide useful information for researchers who are engaging in C−O cross‐coupling reactions. A Cs2CO3‐promoted C−O coupling protocol was developed to enable the facile synthesis of (hetero)aryl ethers under transition‐metal‐free and solvent‐free conditions. Moreover, this protocol was scalable to gram scales and applicable to the synthesis of bioactive molecules, which reflected its potential application prospect. Finally, DFT calculations and a few experiments were carried out to propose a possible pathway.