Pericyclic reactions are frequently proposed as intermediate steps in diverse multistep Au(I)-catalyzed transformations of unsaturated systems, an expanding class of atom-economical reactions that proceed under mild conditions and generally lead to products that exhibit an extraordinary increase in molecular complexity. The feasibility of pericyclic steps occurring in the overall transformations is greater with highly functionalized polyunsaturated systems. Experimental and computational studies concur that Au(I) catalyst guides, if possible, the evolution of the reactant and/or intermediates through pericyclic processes if available to the particular substrate. In general, the activation energies are lower than those for the corresponding reactions in the absence of the coinage metal, in particular when Au(I) is bound to a carbon atom of the pericyclic array. C 2012 John Wiley & Sons, Ltd.