Palladium‐Catalyzed Negishi Cross‐Coupling Reaction of Difluoroiodomethane with Arylzinc Reagents

Abstract

Abstract The catalytic difluoromethylation of arylzinc reagents with difluoroiodomethane in the presence of Pd 2 (dba) 3 /Xantphos is described to produce difluoromethyl products. Mechanistic investigations reveal that the oxidative addition of difluoroiodomethane to [(Xantphos)Pd 0 ] provides trans ‐[(Xantphos)Pd II (I)CF 2 H], which is subsequently transformed to cis ‐[(Xantphos)Pd II (Ph)CF 2 H] through transmetalation of phenylzinc. Next, reductive elimination occurs ( t 1/2 =44.7 min at −10 °C) to give PhCF 2 H. The structural changes in [(Xantphos)Pd II (Ph)CF 2 H] from trans to cis facilitates reductive elimination of PhCF 2 H.