910050-89-4Relevant academic research and scientific papers
Iron(III)-promoted aza-prins-cyclization: Direct synthesis of six-membered azacycles
Carballo, Ruben M.,Ramirez, Miguel A.,Rodriguez, Matias L.,Martin, Victor S.,Padron, Juan I.
, p. 3837 - 3840 (2007/10/03)
A new iron(III) halide-promoted aza-Prins cyclization between γ,δ-unsaturated tosylamines and aldehydes provides six-membered azacycles in good to excellent yields. The process is based on the consecutive generation of γ-unsaturated-iminium ion and further nucleophilic attack by the unsaturated carbon-carbon bond. Homoallyl tosylamine leads to trans-2-alkyl-4-halo-1-tosylpiperidine as the major isomer. In addition, the alkyne aza-Prins cyclization between homopropargyl tosylamine and aldehydes gives 2-alkyl-4-halo-1-tosyl-1,2,5,6-tetrahydropyridines as the only cyclic products.
