TY - JOUR
T1 - Lewis acid induced rearrangement of 2,3-epoxy sulfides; regiospecific trapping of thiiranium ion intermediates with nitrogen heterocycles and amides. Use of imines as nucleophilic equivalents for the selective monoalkylation of primary amines
AU - Gill, Duncan M.
AU - Pegg, Neil A.
AU - Rayner, Christopher M.
PY - 1996/3/4
Y1 - 1996/3/4
N2 - The Lewis acid induced conversion of 2,3-epoxy sulfides into the corresponding 3-trimethylsilyloxy-1,2-thiiranium ions is described. Such intermediates react with silylated nitrogen heterocycles and amides regiospecifically to form 1-substituted-3-hydroxy-2-thioethers in good to moderate yields with full stereochemical control. Exclusive N-alkylation is observed. When simple primary amines are used as nucleophiles, only products of polyalkylation are isolated. However, imines can be effectively used as the nucleophilic equivalent of a primary amine, the initially formed iminium ions being readily hydrolysed by aqueous base to liberate a secondary amine, the product of overall selective monoalkylation of a primary amine.
AB - The Lewis acid induced conversion of 2,3-epoxy sulfides into the corresponding 3-trimethylsilyloxy-1,2-thiiranium ions is described. Such intermediates react with silylated nitrogen heterocycles and amides regiospecifically to form 1-substituted-3-hydroxy-2-thioethers in good to moderate yields with full stereochemical control. Exclusive N-alkylation is observed. When simple primary amines are used as nucleophiles, only products of polyalkylation are isolated. However, imines can be effectively used as the nucleophilic equivalent of a primary amine, the initially formed iminium ions being readily hydrolysed by aqueous base to liberate a secondary amine, the product of overall selective monoalkylation of a primary amine.
UR - http://www.scopus.com/inward/record.url?scp=0030030819&partnerID=8YFLogxK
U2 - 10.1016/0040-4020(96)00036-1
DO - 10.1016/0040-4020(96)00036-1
M3 - Article
AN - SCOPUS:0030030819
VL - 52
SP - 3609
EP - 3630
JO - Tetrahedron
JF - Tetrahedron
SN - 0040-4020
IS - 10
ER -