Catalytic enantioselective construction of all-carbon quaternary stereocenters: synthetic and mechanistic studies of the C-acylation of silyl ketene acetals.
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).
Mermerian
Ara H
AH
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Fu
Gregory C
GC
D000080:Acetals / Q000737:chemistry*; D000215:Acylation; D000812:Anhydrides / Q000737:chemistry; D002384:Catalysis; D005030:Ethylenes / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D011726:Pyridinium Compounds / Q000737:chemistry; D012821:Silanes / Q000737:chemistry*; D013237:Stereoisomerism
D000080:Acetals; D000812:Anhydrides; D005030:Ethylenes; D007659:Ketones; D011726:Pyridinium Compounds; D012821:Silanes; C008223:ketene