Imidazolinium salts as catalysts for the ring-opening alkylation of meso epoxides by alkylaluminum complexes

[GRAPHICS] Imidazolinium salts and their N heterocyclic carbene (NHC) derivatives catalyze the alkylation of a variety of meso epoxides in the presence of triethylaluminum (yield = 70-90%), under mild conditions, Imidazolinium salts are better catalysts than their NHC derivatives but can lead to dimerization side reactions under extended reaction time. Preformed NHC.AlEt3 complexes and Wanzlick-type olefins, which are dimers of free NHCs, are also catalysts for this reaction.