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Cerium( III ) Triflate versus Cerium( III ) Chloride: Anion Dependence of Lewis Acid Behavior in the Deprotection of PMB Ethers
Author(s) -
Bartoli Giuseppe,
Dalpozzo Renato,
Nino Antonio De,
Maiuolo Loredana,
Nardi Monica,
Procopio Antonio,
Tagarelli Antonio
Publication year - 2004
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200400039
Subject(s) - chemistry , cerium , trifluoromethanesulfonate , sodium iodide , chloride , iodide , electrophile , lewis acids and bases , polymer chemistry , organic chemistry , medicinal chemistry , catalysis
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 additions to double bonds. A comparison between the mechanisms of cerium triflate and cerium chloride is reported. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)