Thermal Intramolecular [4 + 2] Cycloadditions of Allenamides: A Stereoselective Tandem Propargyl Amide Isomerization−Cycloaddition
作者:Andrew G. Lohse、Richard P. Hsung
DOI:10.1021/ol901283m
日期:2009.8.6
A stereoselective intramolecular normal demand [4 + 2] cycloaddition of allenamides under thermal conditions without metal assistance is described. This work led to the development of a stereoselective tandem propargyl amide-isomerization−[4 + 2] cycloaddition sequence amenable for rapid assembly of complex nitrogen heterocycles.
COMPOUNDS FOR USE IN IMAGING, DIAGNOSING, AND/OR TREATMENT OF DISEASES OF THE CENTRAL NERVOUS SYSTEM OR OF TUMORS
申请人:Piramal Imaging SA
公开号:EP2217549B1
公开(公告)日:2017-04-19
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