BF3·OEt2-Mediated Highly Regioselective SN2-Type Ring-Opening of N-Activated Aziridines and N-Activated Azetidines by Tetraalkylammonium Halides
摘要:
A highly regioselective Lewis acid-mediated S(N)2-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(N)2 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.
Site‐Selective Distal C(sp3)−H Bromination of Aliphatic Amines as a Gateway for Forging Nitrogen‐Containing sp3 Architectures
作者:Jinhong Chen、Clarence Tan、Jesus Rodrigalvarez、Shuai Zhang、Ruben Martin
DOI:10.1002/anie.202406485
日期:2024.8.12
A site-selective bromination of C(sp3)−H bonds in unprotected aliphatic amines has been developed, achieved by tuning of the electronics properties of the proximal C−H bonds via substrate protonation. Consecutive intramolecular cyclization of alkyl bromide offered a series of N-containing heterocycles characterized by high ring strains. Moreover, the resulting C(sp3)−Br serves as a synthetic linchpin