Imidazolinium Salts as Catalysts for the Ring-Opening Alkylation of meso Epoxides by Alkylaluminum Complexes
journal contributionposted on 16.06.2001, 00:00 by Hongying Zhou, E. Joseph Campbell, SonBinh T. Nguyen
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.