Isoreactive Relations in Chemistry

Isoelectronic and isolobal analogies are powerful tools for comparing the electronic structures of molecular fragments, but they do not necessarily capture similarities in chemical reactivity. In this perspective, we introduce the concept of isoreactive relations to address cases in which structurally distinct fragments support chemically productive outcomes despite dissimilar composition. This idea emerged from our studies on boryl migration, where replacing a hydride with a boron-containing substituent unexpectedly unlocked new reaction pathways. More broadly, isoreactive relations should provide a framework for identifying mechanistic parallels that extend beyond the scope of traditional electronic comparisons. By embracing this reactivity-centered perspective, it should become possible to uncover and experimentally validate unconventional fragment substitutions that lead to novel transformations.