BF3·OEt2-Mediated highly regioselective S N2-type ring-opening of N-activated aziridines and N-activated azetidines by tetraalkylammonium halides

Article abstract of DOI:10.1021/jo902244y

(Chemical Equation Presented) A highly regioselective Lewis acid-mediated S_N2-type ring-opening of N-sulfonylaziridines and azetidines with tetraalkylammonium halides in CH₂Cl₂ solution to afford 1,2- and 1,3-haloamines in excellent yields is described. An easy diastereoselective route toward substituted chiral N-tosylaziridines has been developed. The mechanism of ring-opening via S_N2 pathway has been confirmed by the formation of chiral haloamines with excellent er and dr. Chloroamines obtained from 2,3-disubstituted aziridines were converted to the chiral N-tosylamines via radical dehalogenation. 2009 American Chemical Society.