Aluminum Triiodide-Mediated Cleavage of o-Hydroxyphenyl Alkyl Ethers Using Inorganic Bases and Metal Oxides as Acid Scavengers

作者：Tian, Juan^*; Yi, Cuicui; He, Zhoujun; Yao, Ming; Sang, Dayong^*

来源：ChemistrySelect, 2017, 2(28): 9211-9214.

DOI：10.1002/slct.201701685

• ATAS
• catechol monoether
• demethylation
• ether cleavage
• eugenol

Studies have shown that a proper acid scavenger is a requisite to prevent acid-labile functional groups from deterioration during aluminum triiodide-mediated cleavage of o-hydroxyphenyl alkyl ethers. In this work, the acid scavenging effect of inexpensive and bench stable inorganic bases and metal oxides were evaluated using eugenol as a model substrate. Among the bases and oxides screened, KOtBu, Na2CO3, CaO, CuO and ZnO were found effective. The method is compatible with a variety of functional groups, and was applied successfully in cleaving catechol monoethers such as guaiacol, vanillin, isovanillin, vanillonitrile, isovanillonitrile, acetovanillone, nonivamide, ethylvanillin and o-isopropoxyphenol. The corresponding catechols were obtained in excellent yields. The oxophilicity of aluminum triiodide is not markedly suppressed by these inorganic acid scavengers, making the aluminum triiodide-acid scavenger method effective in cleaving general phenyl methyl ethers such as m-guaiacol, 4-allylanisole, veratraldehyde and methyl eugenol without the anchimeric assistance of an o-hydroxyl group.

• 出版日期2017-9-29
• 单位荆楚理工学院