Organocatalytic head-to-tail dimerization of methacrolein via conjugate addition of methanol: an alcohol activation mechanism proved by electrospray ionization mass spectrometry
conjugate addition of methanol is catalyzed by various organicbases, such as an amine, phosphine, and N-heterocyclic carbene, to give 2,4-dimethyl-2-methoxymethylpentane-1,5-dial in moderate yields. Based on the interpretation of the key intermediates by electrospray ionization mass spectrometry, we propose a reaction mechanism involving the initial conjugate addition of the organicbases to methacrolein