Alcoxycarbonyl complexes

For M = Ru, formamides and amines were the principal products. Substitution of Fe3(CO)i2 for Ru3(CO)i2 results in the formation of carbamate esters (ArNHCOOMe) as the major products, with ureas as the main by-products. Without the metal carbonyl, nitroarenes are recovered imchanged from the reaction mixture. An imido-alcoxycarbonyl complex was suggested as an intermediate in the reaction and the difference between iron and ruthenium was proposed to be due to the different facility of this intermediate to undergo protonation and reductive elimination to give carbamate, or insertion of CO into the M-N bond, followed by hydrogenation, affording formamide (Scheme 13) ... 

PdCUI (L2 = 2 PPha or several N-N or P-N chelating ligands) reacts with alcohols or amines in the presence of CO and a base to yield bis-alcoxycarbonyl or carbamoyl complexes respectively (eqs. 15, 16) ... 

---