169738-71-0Relevant academic research and scientific papers
Lewis Acid Induced Rearrangement of 1-Hetero-2,3-Epoxides. Synthesis, Reactivity and Synthetic Applications of Homochiral Thiiranium and Aziridinium Ion Intermediates
Rayner, Christopher M.
, p. 11 - 21 (1997)
2,3-Epoxy sulfides and 2,3-epoxy amines, prepared in an optically active form via the Sharpless asymmetric epoxidation, both undergo a Lewis acid induced rearrangement to give the corresponding thiiranium and aziridinium ions respectively. These reactive intermediates, generated in situ, react efficiently with a variety of nucleophiles such as silylated aromatic heterocycles, amides, and amines, including amino acid derivatives. Imines can be used as synthetic equivalents of primary amine nucleophiles, which effectively allows selective monoalkylation with a reactive thiiranium ion intermediate. Applications of this new methodology, and mechanistic studies are also discussed.
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
Gill, Duncan M.,Pegg, Neil A.,Rayner, Christopher M.
, p. 3609 - 3630 (2007/10/03)
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.
