Mixed carbene–isocyanide Pd(ii) complexes: synthesis, structures and reactivity towards nucleophiles

Publisher Website
Google Scholar
Abstract
Reaction of the bromo-bridged dimeric monocarbene complex [PdBr2(iPr2-bimy)]2 (1) (iPr2-bimy = 1,3-diisopropylbenzimidazolin-2-ylidene) with various isocyanides afforded a series of mixed carbene–isocyanide complexes [PdBr2(iPr2-bimy)(CN-R)] (2a: R = Cy; 2b: R = nBu; 2c: R = Xyl) as inseparable mixtures of trans- and cis-isomers. The reactivity of 2c towards nucleophiles was studied. A new mixed NHC–ADC Pd(II) complex (4) was obtained in low yield when 2c was reacted with 2,6-dimethylaniline. Reaction of 2c with hydrazine yielded a hydrazine-bridged complex (6) via ligand substitution. In addition, salt metathesis of 2c with AgO2C2F3 afforded a cis arranged complex [Pd(O2CCF3)2(iPr2-bimy)(CN-Xyl)] (cis-7). Most complexes were fully characterized by multinuclei NMR spectroscopies, ESI or FAB mass spectrometry and X-ray diffraction analysis.