ISSN:
0009-2940
Keywords:
Iron complexes
;
Cobalt complexes
;
Clusters
;
Vinylidene ligand
;
Carbon - carbon coupling
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Addition of Inorganic and Organic Nucleophiles to the Vinylidene Ligand of the Cluster FeCo2(CO)9(μ3-C=CH2)The C=CH2 ligand of the cluster FeCo2(CO)9(μ3-C=CH2) (1) is electrophilic at the terminal C atom. Soft inorganic nucleophiles [Nu - PR3, (CH3)2SO, CN-, SCN-] are added to form the zwitterionic complexes FeCo2(CO)9(μ3-C-CH2-Nu) (4, 7, 8), as proved by the structure determination of FeCo2(CO)9(μ3-C—CH2 - PMe3) (4a). The products are of low thermal stability. Upon heating, the PR3 derivatives rearrange to the CO substitution products FeCo2(CO)8(PR3)(μ3-C=CH2) (5, 6). C-C coupling is achieved by addition of malonic ester anion derivatives [X - CH - CO2Me] (X=MeO2C, CN, Br). The anionic addition product for X=MeO2C (10a) can be protonated to form HFeCo2(CO)9[μ3 C—CH2 - CH(COOMe)2] (11) which liberates H2 upon warming resulting in FeCo2(CO)9[μ3-C=CH - CH(COOMe)2] (12). Thus, a substitution of a vinylidene H atom has been performed by an HX addition/H2 elimination sequence. Phosphorus ylides R3P=CHX [X=H, SiMe3, Cl, CHO, C(O)Ph, COOR] are also added with C—C coupling to yield the complexes FeCo2(CO)9(μ3-C—CH2 - CHX - PR3) (15, 16). The structure determination of the compound with X=EtO2C and R=Ph (16c) proves that these complexes differ from the complexes 4 just by insertion of one methylene unit.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19911240508
Permalink
