Lewis Acid-Mediated Highly Regioselective S_N2-Type Ring-Opening of 2-Aryl-<i>N</i>-tosylazetidines and Aziridines by Alcohols

Abstract

Lewis acid-mediated highly regioselective SN2-type ring-opening of 2-aryl-N-tosylazetidines with alcohols to afford various 1,3-amino ethers in excellent yields with good enantiomeric excess is described. Similar SN2-type ring-opening of chiral 2-phenyl-N-tosylaziridine with various alcohols produces the corresponding nonracemic 1,2-amino ethers in excellent yields and good ee. The mechanism of the ring-opening of aziridines and azetidines via an SN2 pathway is supported by the formation of nonracemic amino ethers.