Synthetic Access to α-Oxoketene Aminals by the Nucleophilic Addition of Enol Silane-Derived Palladium(II) Enolates to Carbodiimides.

Abstract

Synthetically important α-oxoketene aminal intermediates can now be accessed from readily available and inexpensive carbodiimides as starting materials via the nucleophilic addition of palladium enolates derived from enol silane precursors. This operationally simple method features mild reaction conditions, including open air atmosphere, ligand-free metal catalysis, broad substrate scope, and multi-gram scalability. Select synthetic applications that take advantage of the enamine character of α-oxoketene aminals and involve C-nucleophilic additions to electrophilic systems, including an α,β-unsaturated ester, an azo dicarboxylate, an aralkyl halide, and an aldehyde, are demonstrated.