Ytterbium tricyanide: Preparation and catalytic activity for the addition of cyanotrimethylsilane to carbonyl compounds

Ytterbium tricyanide was obtained quantitatively by the reaction of ytterbium tri‐isopropoxide with cyanotrimethylsilane. The addition of cyanotrimethylsilane to various carbonyl compounds was catalyzed effectively by ytterbium tricyanide to proceed under mild conditions giving the adducts in high selectivities. 2‐Methylcyclohexanone yielded the adduct in a highly diastereoselective manner and the reagent system also effectively gave the adducts from easily enolizable ketones as well as from acid‐sensitive ones. α,β‐Unsaturated ketones and aldehydes afforded 1,2‐adducts exclusively.