98688-87-0Relevant articles and documents
Intermolecular formation of C-H bonds: Application to the synthesis of heterobimetallic complexes
Warner, Keith E.,Norton, Jack R.
, p. 2150 - 2160 (2008/10/08)
The reactions of various alkylmetal carbonyl complexes (e.g., MeMn(CO)5, EtRe(CO)5, MeFe(CO)2Cp, Me2Os(CO)4) with various transition-metal hydrides (e.g., HRe(CO)5, H2Os(CO)4, HMn(CO)5, HW(CO)3Cp) have been examined in solvents of different coordinating abilities. In coordinating solvents the metal-containing products are solvated dinuclear complexes; in noncoordinating solvents the metal-containing products are polynuclear hydrides, formed by the coordination of a second equivalent of the hydride reactant. The vacant coordination site is created on the metal that originally bears the alkyl ligand: in CH3CN, MeMn(CO)5 and HRe(CO)5 give (CH3CN)Mn(CO)4Re(CO)5, whereas EtRe(CO)5 and HMn(CO)5 give (CH3CN)Re(CO)4Mn(CO)5. The organic products eliminated are generally aldehydes (although alkane elimination is also seen, particularly when the initial alkyl carbonyl complex is a dialkyl). The reaction is fastest in coordinating solvents and for the alkyl carbonyl complexes that most readily form acyls: MeMn(CO)5 and those complexes of other metals (e.g., EtRe(CO)5) that contain alkyl groups that migrate more readily than methyl. When heated in acetonitrile solution, EtRe(CO)5, i-BuRe(CO)5, and some other alkyl carbonyl complexes equilibrate with solvated acyl complexes such as cis-RC(O)(CH3CN)Re(CO)4; these solvated acyl complexes react rapidly at low temperatures with hydrides to eliminate aldehydes. In favorable cases, the reactions of alkyl carbonyls with transition-metal hydrides are synthetically attractive routes to heterobimetallic complexes.