Chaffey Dawn R, Alamillo-Ferrer Carla, Davies Thomas E, Taylor Stuart H, Tomkinson Nicholas C O, Graham Andrew E
School of Applied Sciences, University of South Wales, Pontypridd CF37 4AT, UK.
WestCHEM, Department of Pure and Applied Chemistry, Thomas Graham Building, University of Strathclyde, Glasgow G1 1XL, UK.
ACS Omega. 2019 Sep 23;4(14):15985-15991. doi: 10.1021/acsomega.9b02059. eCollection 2019 Oct 1.
The product distribution of ethers formed from the reaction of cinnamyl alcohol with orthoesters in the presence of indium (III) triflate (InOTf) is dependent on both the reaction temperature and catalyst loading. Carrying out the reaction at room temperature under low loadings of the catalyst leads to a facile reaction generating the unexpected secondary allyl ether as the major product. In contrast, carrying out the reaction under higher catalyst loadings at elevated temperatures provides the expected primary linear ether in high yield and with excellent selectivity. The etherification reaction is also effective in the presence of acetals and ketals in place of orthoesters and allows for the development of the procedure to encompass a telescoped etherification protocol in which the acetal is generated in situ.
在三氟甲磺酸铟（InOTf）存在下，肉桂醇与原酸酯反应生成醚的产物分布取决于反应温度和催化剂用量。在室温下低催化剂用量条件下进行反应，会发生 facile 反应，生成意外的仲烯丙基醚作为主要产物。相比之下，在高温下较高催化剂用量条件下进行反应，则能以高收率和优异的选择性得到预期的伯线性醚。该醚化反应在使用缩醛和缩酮代替原酸酯时也有效，并且可以开发出一种包含缩合醚化方案的方法，其中缩醛是原位生成的。
