SACs are known to be chemoselective owing to the restricted adsorption configuration in contrast to the diverse binding sites on conventional heterogeneous catalysts (Figure ). This allows rapid replication of molecular catalysis for the synthesis of complex molecules. However, as every coin has two sides, this could be problematic when selectivity regulation toward specific products is needed for SACs. Beyond conventional strategies via modulating the electronic structure and coordination environment, (reversible) dynamic aggregation offers a distinct advantage in breaking the selectivity limitation, particularly for those reactions that require adjacent metal sites (such as CO2RR and complete oxidation of hydrocarbons ).