Electroauxiliary-assisted sequential introduction of two carbon nucleophiles on the same alpha-carbon of nitrogen: application to the synthesis of spiro compounds.

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.