Stereoselective Intramolecular [4 + 3] Cycloadditions of Nitrogen-Stabilized Chiral Oxyallyl Cations via Epoxidation of N-Tethered Allenamides
作者:Hui Xiong、Jian Huang、Sunil K. Ghosh、Richard P. Hsung
DOI:10.1021/ja030416n
日期:2003.10.1
first intramolecular [4 + 3] cycloaddition reaction using nitrogen-stabilized chiral oxyallylcations that are tethered to furan or diene through the nitrogen atom is described here. Formation of these nitrogen-stabilized chiral oxyallylcations is achieved by a chemoselective epoxidation of chiral allenamides via syringe pump addition of dimethyl dioxirane. The ensuing cycloaddition can be carried out