Trifluoroacetimidoyl metal complexes are useful intermediates for the selective synthesis of organofluorine compounds. Herein, we report preparations, structures, and reactions of fluorinated imidoyl palladium complexes. Oxidative addition of trifluoroacetimidoyl halides to Pd(PPh3)4 afforded quantitatively the imidoyl palladium(II) complexes with phosphine ligands. The reaction of trifluoroacetimidoyl iodides with Pd2(dba)3 provided the phosphine-free imidoyl palladium complex in high yields. The X-ray crystal structure analysis of the phosphine-free complex [Pd(μ-I){μ-C(CF3)═N(PMP)}]4 revealed a cyclic tetranuclear structure containing the imidoyl and iodo bridges. The generation of aminotrifluoromethylcarbene equivalents by protonation or electrophilic alkylation of imidoyl palladium(II) complexes is discussed.

A new methodology for aromatic difluoromethylation is described. Aryl iodides reacted with α-silyldifluoroacetates upon treatment with copper catalyst in DMSO or DME to give the corresponding aryldifluoroacetates in moderate to good yields. The subsequent hydrolysis of aryldifluoroacetates and KF-promoted decarboxylation afforded a variety of difluoromethyl aromatics.