Iron(III)-Catalyzed Consecutive Aza-Cope−Mannich Cyclization: Synthesis of <i>trans</i>-3,5-Dialkyl Pyrrolidines and 3,5-Dialkyl-2,5-dihydro-1<i>H</i>-pyrroles
作者:Rubén M. Carballo、Martín Purino、Miguel A. Ramírez、Víctor S. Martín、Juan I. Padrón
DOI:10.1021/ol102372c
日期:2010.11.19
efficient alkene aza-Cope−Mannich cyclization between 2-hydroxy homoallyl tosylamine and aldehydes in the presence of iron(III) salts to obtain 3-alkyl-1-tosyl pyrrolidines in good yields is described. The process is based on the consecutive generation of a γ-unsaturated iminium ion, 2-azonia-[3,3]-sigmatropic rearrangement, and further intramolecular Mannich reaction. Iron(III) salts are also shown to be