A free radical Mannich type reaction: selective alpha-CH aminomethylation of ethers by Ti(III)/t-BuOOH system under aqueous acidic conditions

tert-Butoxy radical, generated by Ti(Ill)-one electron reduction of tert-butylhydroperoxide, selectively abstracts an a-H atom from ethers. The resulting alpha-ethereal radicals add to the C-atom of methylene immiurn salts, formed in situ under aqueous acidic conditions, leading to a one-pot aminomethylation of ethers at room temperature. The aminoalkylation of ethers is also considered and the role of the metal ion is discussed. (c) 2006 Elsevier Ltd. All rights reserved.