Rs. Srivastava et al., SYNTHESIS, CHARACTERIZATION, AND CARBONYLATION REACTIONS OF METHYLPALLADIUM AMIDE, CARBAMATE, AND ALKYL CARBONATE COMPLEXES, Journal of organometallic chemistry, 451(1-2), 1993, pp. 221-229
A series of trans- and cis-methylpalladium carbamate complexes PdMe(OC
ONRR')L2 (L = tertiary phosphine; R, R' = H, alkyl, and phenyl) was pr
epared by the reaction of dimethylpalladium complexes with primary or
secondary amine and carbon dioxide. When diphenylamine was used, methy
lpalladium amide complexes trans-PdMe(NPh2)L2 (L = PMe3 and PEt2Ph) we
re isolated instead of carbamates. The carbamate and amide complexes t
hus prepared were characterized by IR and NMR spectroscopy and element
al analysis. The carbamate complex trans-PdMe(OCONEt2)(PMe3)2 released
one of the PMe3 ligands on recrystallization to form a dimeric compou
nd Pd2Me2(mu-OCONEt2)2(PMe3)2, whose structure was determined by X-ray
diffraction study. The carbamate complexes reacted with carbon monoxi
de under pressure to give corresponding alpha-keto amide (MeCOCONRR')
and amide (MeCONRR'). Reactions of dimethylpalladium complexes with al
cohols and carbon dioxide gave methylpalladium alkyl carbonate complex
es trans-PdMe(OCOOR)L2 (R = Me, (s)Bu; L = PMe3, PPh 3). Treatment of
alkyl carbonate complexes with carbon monoxide afforded the correspond
ing alkyl acetate as the sole carbonylation product.