The first tail-to-tail dimerization of methacrylonitrile (MAN) has been realized by the cooperative use of N-heterocyclic carbene (NHC) and Brønsted acid catalysts, producing 2, 5-dimethylhex-2-enedinitrile with the E/Z ratio of 24: 76. Although the NHC alone was not effective for the catalysis, the addition of alcohols resulted in the significant increase of the dimer yield up to 82% in the presence of 5 mol% NHC. Detailed experimental studies ...
