The first carbamoyl–carboxylate complex of transition metals: Synthesis and structure of {(OC4H8NH)[OC4H8NC(O)]Pd}2(μ-CMe3CO2)2

•Reaction of palladium carbonyl carboxylate clusters with morpholine was studied.•The main product was found to be binuclear carbamoyl–carboxylate complex.•The complex was characterized by XRD analysis.•That is the first fully characterized carbamoyl–carboxylate complex of TM.•Amine and carboxylate anion were found to be proton acceptors in the reaction.

Reactions of palladium(I) carbonyl carboxylate complexes [Pd(μ-CO)(μ-RCO2)]n with secondary amines on the example of morpholine were studied. It was found that intramolecular carbonylation of amine in coordination sphere of polynuclear palladium species proceeds and binuclear palladium carbamoyl complex {(OC4H8NH)[OC4H8NC(O)]Pd}2(μ-RCO2)2 forms as a result. This is the first structurally characterized carbamoyl–carboxylate complex of transition metals. Also it was shown that morpholine itself and carboxylate-anions act as proton acceptors in the reaction of carbonylation of morpholine by coordinated CO.

Graphical abstractReactions of palladium(I) carbonyl carboxylate complexes [Pd(μ-CO)(μ-RCO2)]n with secondary amines on the example of morpholine were studied. It was found that intramolecular carbonylation of amine in coordination sphere of polynuclear palladium species proceeds and binuclear palladium carbamoyl complexes {(OC4H8NH)[OC4H8NC(O)]Pd}2(μ-RCO2)2 forms as a result.Figure optionsDownload full-size imageDownload as PowerPoint slide