Catalytic Enantioselective Construction of All-Carbon Quaternary Stereocenters: Synthetic and Mechanistic Studies of the C-Acylation of Silyl Ketene Acetals
摘要:
With the aid of an appropriate chiral catalyst, acyclic silyl ketene acetals react with anhydrides to furnish 1,3-dicarbonyl compounds that bear all-carbon quaternary stereocenters in good ee and yield. Mechanistic studies provide strong support for a catalytic cycle that involves activation of both the electrophile (anhydride -> acylpyridinium) and the nucleophile (silyl ketene acetal -> enolate).
Catalytic Enantioselective Construction of All-Carbon Quaternary Stereocenters: Synthetic and Mechanistic Studies of the C-Acylation of Silyl Ketene Acetals
摘要:
With the aid of an appropriate chiral catalyst, acyclic silyl ketene acetals react with anhydrides to furnish 1,3-dicarbonyl compounds that bear all-carbon quaternary stereocenters in good ee and yield. Mechanistic studies provide strong support for a catalytic cycle that involves activation of both the electrophile (anhydride -> acylpyridinium) and the nucleophile (silyl ketene acetal -> enolate).