Tandem Pummerer/Mannich Cyclization Cascade of α-Sulfinylamides as a Method To Prepare Aza-Heterocycles
作者:Albert Padwa、Todd M. Heidelbaugh、Jeffrey T. Kuethe、Michael S. McClure、Qiu Wang
DOI:10.1021/jo020083x
日期:2002.8.1
particularly suited for the assembly of natural product scaffolds. Some preliminary studies were directed toward both mesembrine and deethylibophyllidine. When the model Z-enamido sulfoxide 33 was heated with p-TsOH, a 80% yield of tosylate 34 was obtained as a single diastereomer. In this case, the carbocation intermediate derived from cyclization onto the terminal pi-bond was trapped with p-TsOH from the least