Cerium(III) Triflate versus Cerium(III) Chloride: Anion Dependence of Lewis Acid Behavior in the Deprotection of PMB Ethers
作者:Giuseppe Bartoli、Renato Dalpozzo、Antonio De Nino、Loredana Maiuolo、Monica Nardi、Antonio Procopio、Antonio Tagarelli
DOI:10.1002/ejoc.200400039
日期:2004.5
Cerium(III) triflate deprotects p-methoxybenzyl ethers of simple alcohols better than the cerium(III) chloride/sodium iodide system. It can be used in 1% M instead of equimolecular amounts, giving better yields. Aromatic alcohols rearrange, but the addition of a scavenger overcomes this drawback. Unfortunately, unsaturated alcohols are deprotected with decomposition, probably due to side electrophilic
三氟甲磺酸铈 (III) 比氯化铈 (III)/碘化钠体系更好地对简单醇的对甲氧基苄基醚进行脱保护。它可以以 1% M 代替等分子量使用,从而获得更好的产率。芳香醇重排,但添加清除剂克服了这个缺点。不幸的是,不饱和醇会因分解而脱保护,这可能是由于双键的侧亲电加成。报道了三氟甲磺酸铈和氯化铈机制之间的比较。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)