We next decided to increase the size of the DCL. By adding three symmetric Homo-PROTACs as starting materials, the number of PROTAC library members increases from three to 15 for this second library, alongside five monomeric thiols (Figure ). Aiming to portray the whole chemical space covered by the previously synthesized symmetric Homo-PROTACs, we included symmetric Homo-PROTACs with good (MeSH2), average (MeSH3), and very poor (MeSH5) potency as starting materials in this extended DCC experiment (Figure ). As in the first DCC experiment, addition of VCB as templating biomolecule led to significant changes in the distribution of species in the equilibrated library (Figure ). While all monomeric species (grey) as well as DCL-PROTACs with very short linkers (four to seven atoms, lilac and lavender) were depleted in the templated library, 14-and 18-atom species (green and pink) were enriched in presence of VCB (Figure ).