Insertion reactions of isocyanides into the Metal-C(sp3) bonds of ylide complexes

The synthesis of the previously reported complexes [Pd{(C,C-CHCO2R)(2)PPh2}(mu-Cl)](2) (R = Me (1), Et (2)) has been considerably improved by reacting the phosphonium salts [Ph2P(CH2CO2R)(2)]Cl with Pd(OAc)(2). Complexes 1 and 2 react with isocyanides R'NC (R' = C6H4Me2-2,6 (Xy), C6H4I-2 and Bu-t) to give complexes of the type [Pd{C,C-{C(CO2R) = C(NHR')}(CHCO2R)}PPh2}Cl(CNR')], resulting from the insertion of the unsaturated molecule in one of their Pd-C bonds and the hydrogen transfer from the methine CH to the iminobenzoyl nitrogen. These are the first insertion reactions observed in the Pd-C bond of a P-ylide complex. The crystal structure of the complex [Pd{C,C-{C(CO2Me)=C(NHXy)}(CHCO2Me)}PPh2}Cl(CNXy)] (3) is reported. (c) 2019 Elsevier B.V. All rights reserved.