Intramolecular [3 + 2]-Cycloaddition Reaction of Push−Pull Dipoles Across Heteroaromatic π-Systems
作者:José M. Mejía-Oneto、Albert Padwa
DOI:10.1021/ol048915w
日期:2004.9.1
Push-pull dipoles generated from the Rh(II)-catalyzed reaction of diazo imides containing tethered heteroaromatic rings undergo successful [3 + 2]-cycloaddition across the 2,3-pi-bond to provide novel pentacyclic compounds in good to excellent yields in a stereocontrolled fashion. The facility of the cycloaddition is critically dependent on conformational factors in the transition state.
Cycloaddition Chemistry of 2-Vinyl-Substituted Indoles and Related Heteroaromatic Systems
作者:Albert Padwa、Stephen M. Lynch、José M. Mejía-Oneto、Hongjun Zhang
DOI:10.1021/jo047834a
日期:2005.3.1
The intramolecular Diels−Alder cycloaddition reaction (IMDAF) of several N-phenylsulfonylindolyl-substituted furanyl carbamates containing a tethered π-bond on the indole ring were examined as an approach to the iboga alkaloid catharanthine. Only in the case where the tethered π-bond contained two carbomethoxy groups did the [4 + 2]-cycloaddition occur. Push−pull dipoles generated from the Rh(II)-catalyzed