The development of new functional materials requires reliable conjugation chemistry for coupling molecular fragments under mild reaction conditions. The Diels–Alder (DA) reaction has been used in organic synthesis extensively over the past 90 years, but only recently has its ability to form fast and stable linkages been explored. New developments in small molecule DA reactivity have led to advances in protecting group chemistry and conjugation strategies. During my graduate studies, we developed novel diene-linkers, attached them onto antibodies, and conjugated maleimide-drugs to form DA antibody–drug conjugates. While exploring these adducts, we were able to exploit the lower retro-DA temperature of endo furan–maleimide adducts towards a new protecting group for maleimides in polymer synthesis. We also developed norbornadiene-containing polymers as a new “protected” form of cyclopentadiene that can be unmasked at room temperature with readily available reagents. These three conjugation strategies have enabled facile preparation of functional materials with more stable bonds and greater architectural complexity
