Electroauxiliary-Assisted Sequential Introduction of Two Carbon Nucleophiles on the Same α-Carbon of Nitrogen: Application to the Synthesis of Spiro Compounds
摘要:
The sequential introduction of two carbon nucleophiles on the same alpha-carbon of nitrogen by using selective oxidative cleavage of two silyl groups as electroauxilialies has been accomplished. The combination of this expedient transformation and ring-closing metathesis enables reliable and straightforward syntheses of nitrogen-containing spiro compounds, such as cephalotaxine.
Photochemical Rearrangement of <i>N</i>-Chlorolactams: A Route to <i>N</i>-Heterocycles through Concerted Ring Contraction
作者:Dana K. Winter、Alexandre Drouin、Jean Lessard、Claude Spino
DOI:10.1021/jo100181h
日期:2010.4.16
We report a novel ringcontraction allowing the direct conversion of N-chlorolactams to their corresponding ring-contraction N-heterocycles upon photolysis. Results show that the rearrangement occurs with a variety of N-chlorolactams and that the greater the substitution at the migrating carbon, the greater the yield of product. Importantly, stereochemistry at the migrating carbon is conserved in the