Endo-benzonorbornen-2-ol as an efficient non-natural chiral auxiliary in the asymmetric aza-Diels–Alder reactions between cyclopentadiene and (1-phenylethyl)iminoacetates
作者:Carlos A. D. Sousa、Miguel A. Maestro、Xerardo Garcia-Mera、José E. Rodríguez-Borges
DOI:10.1039/c4ra11143e
日期:——
Exo-2-azabicyclo[2.2.1]hept-5-enes were obtained by cycloaddition reactions between cyclopentadiene and protonated (S)- and (R)-1-phenylethylimines of (1R,endo)-benzonorbornen-2-yl glyoxylate. The non-natural (1R,endo)-benzonorbornen-2-ol proved to be an efficient chiral auxiliary in these asymmetric aza-Diels–Alder reactions, which afforded only exo-cycloadducts with 1S : 1R diastereomeric ratios