Difluoromethane as a precursor to difluoromethyl borates†
Difluoromethane (CF2H2) is an ecologically-friendly refrigerant which holds promise as a source of CF2H−. However, the weak acidity (pKa = 35–41) and low stability of the conjugate base have prevented its utilization as a chemical feedstock. In this manuscript, we use a Lewis pair approach to deprotonate CF2H2 and capture CF2H− as R3B–CF2H− adducts. One reagent can be used as a base-free Suzuki reagent in palladium-mediated difluoromethylation, where CF2H− transfer is templated by precoordination to an azaborine derived R3B–CF2H− reagent.