A catalytic asymmetric intramolecular homologation of simple ketones with α-diazoesters was firstly accomplished with a chiral N,N'-dioxide-Sc(OTf)3 complex. This method provides an efficient access to chiral cyclic α-aryl/alkyl β-ketoesters containing an all-carbon quaternary stereocenter. Under mild conditions, a variety of aryl- and alkyl-substituted ketone groups reacted with α-diazoester groups smoothly through an intramolecular addition/rearrangement process, producing the β-ketoesters in high yield and enantiomeric excess.
Keywords: asymmetric catalysis; homologation; scandium; α-diazoesters; β-ketoesters.
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