Electrochemical defluorinative Matteson-type homologation

The Matteson homologation, first developed in 1980, elongates carbon chains by insertion into a C-B bond¹. This versatile reaction traditionally requires three steps: carbanion formation, nucleophilic addition to organoboron and a thermo- or Lewis-acid-promoted boronate rearrangement. These processes often demand exacting conditions, including cryogenic temperatures and handling of air- and moisture-sensitive reagents^2,3. Here we report a Matteson-type homologation, which integrates these three transformations into a one-pot electrochemical process. This proof-of-concept approach combines electroreductive defluorination with boronate rearrangement, eliminating the need for organolithium reagents, cryogenic conditions or specialist setups. The available trifluoromethylarenes are used as carbenoid precursors, expanding the scope of the Matteson reaction. Comprehensive mechanistic studies, including identification of key reaction intermediates, density functional theory calculations and electrochemical analysis, confirm the involvement of boronate formation and rearrangement in this e-Matteson homologation.