The spatial and temporal control approaches discussed above provide the means for coupling multiple catalytic cycles in a single reaction vessel. In this section, we will focus on utility of spatialtemporal control to couple different catalytic cycles, by either exploiting the switchable catalysis of a single precatalyst or by reconciling incompatible issues among multiple catalytic systems to generate products that would otherwise be difficult to synthesize. In this regard, polymerization reactions are the best examples to showcase how complex products can be generated from simple building blocks.