An Experimental and Computational Investigation into the Allylboration/Defluorinative Semipinacol Rearrangement Cascade Reaction

Allylboration reactions using (3-fluoroallyl)boronates enable concurrent C-C bond formation and C-F bond activation through a cascade process. The resulting borate adduct promotes a defluorinative semipinacol rearrangement, generating α-functionalized carbonyl products through a coupled C-F cleavage/1,2-migration sequence. The transformation proceeds with high selectivity for aryl migration and tolerates a range of carbonyl substrates. Computational analysis clarifies the electronic factors governing the experimentally observed migratory aptitude trends, providing mechanistic insight into this distinct mode of defluorination-driven skeletal reorganization.