We explore the factors leading to regioselective nucleophilic additions in gold(I)‐mediated reactions with allenes through DFT analysis of model systems. The feasibility of intermolecular nucleophilic attack by sydnones and münchnones was evaluated and validated by comparison to several known nucleophiles, the transition states with münchnones being kinetically accessible. The resulting intermediates selectively undergo formal (3 + 3) cyclisations instead of the more usual (3 + 2) pathways, with substituted dihydropyridines as the ultimate products. We propose that the use of mesoionic reagents in gold(I)‐mediated processes is feasible, should regioselectively access different heterocycles, and could enable the development of new methodology in gold(I)‐mediated synthesis.
Garcia‐Padilla et al. (Fri,) studied this question.