Catalytic and regioselective ring expansion of arylcyclobutanones with trimethylsilyldiazomethane. Ligand-dependent entry to beta-ketosilane or enolsilane adducts.

Jennifer A Dabrowski, David C Moebius, Andrew J Wommack, Anne F Kornahrens, Jason S Kingsbury

Index: Org. Lett. 12(16) , 3598-601, (2010)

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Abstract

Divergent reactivity is uncovered in the homologation of arylcyclobutanones with trimethylsilyldiazomethane. With Sc(OTf)(3) as catalyst, enolsilanes are obtained with a high preference for methylene migration. By contrast, Sc(hfac)(3) gives beta-ketosilanes with both regio- and diastereocontrol. Each adduct affords the cyclopentanone upon hydrolysis.