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Mercuration and bromination reactions of ferracarborane 3-(η5-Cp)-4-SMe2-3,1,2-FeC2B9H10 (1) were investigated. Mercuration of 1 under mild conditions (mercury trifluoroacetate in dichloromethane) results in 8-monosubstituted mercury derivative as the only reaction product. Depending on the reaction conditions, bromination of 1 results in 8-mono- or 7,8-disubstituted bromo derivatives. The structures of the monomercury and dibromo derivatives of 1 were established by X-ray analysis.

Stereoselectivity of allylboration of 4-formyl[2.2]paracyclophane, 4-acetyl[2.2]paracyclophane, and 4-hydroxy-5-formyl[2.2]paracyclophane was studied and the relative configurations of the homoallylic alcohols obtained were established. Optically pure (Sp,Sc)-(+)-4-(4-hydroxy-1-methylbut-3-enyl)[2.2]paracyclophane and (Rc,Sc)-(+)-4-hydroxy-5-(4-hydroxybut-3-enyl)[2.2]paracyclophane were synthesized. The possibility of using (Sp,Sc)-(+)-4-(4-hydroxy-4-methylbut-3-enyl)[2.2]paracyclophane as a recoverable chiral auxiliary in asymmetric allylboration of aldehydes was demonstrated.

The reaction of triallylborane with 3-phenylprop-1-yne at 135–140 °C followed by treatment of the reaction mixture with MeOH afforded 7-benzyl-3-methoxy-3-borabicyclo[3.3.1]non-6-ene (1) in 81% yield. Hydroboration of compound1 with a solution of BH3 in THF yielded the tetrahydrofuran complex of 2-phenyl-1-boraadamantane (2). The reactions of trimethylamine or pyridine with compound2 afforded the trimethylamine (3) or pyridine (4) complexes of 2-phenyl-1-boraadamantane. respectively. Hindered rotation about the C(2)−Ph bond in adduct3 was observed by1H and13C NMR spectroscopy. The activation energy of this process is 58.6 kJ mol−1 (determined by 2D1H−1H EXSY spectroscopy).

Reaction of the cluster Os3(μ-CO)(CO)9(μ3-η1:η1:η2-Me3SiC2Me) with HC≡CCOOMe in benzene at 70 °C results in Os3(CO)9{μ3-η1:η1:η2:η2-C(SiMe3)C(Me)C(COOMe)CH× (5), Os3(CO)9{μ3-η1:η1:η2:η2-C(SiMe3)C(Me)C(H)C(COOMe)CH× (6), Os3(CO)9{μ-η1:η1:η4-C(SiMe3)C(Me)C(H)C(COOMe)CH× (7), and Os3(CO)δ{μ3-η1:η1:η4:η1-C(SiMe3)C(Me)C(H)C(COOMe)× complexes (8), containing an osmacyclopentadiene moiety. Complexes5–8 were characterized by1H NMR and IR spectroscopy. The structure of clusters5 and8 was confirmed by X-ray analysis. Complex7 is formed from cluster5 as a result of a new intramolecular rearrangement and complex8 is obtained by decarbonylation of compound6. Complex8 adds PPh3 to give Os3(CO)δ(PPh3){μ-η1:η1:η4-C(SiMe3)C(Me)C(H)C(COOMe)×.

Reactions of the alkyne cluster Os3(μ-CO)(CO)9(μ3-Me3C2Me) with alkynes Me3SiC≡CR (R=Me, Bun) in refluxing hexane result in the formation of clusters Os3(CO)9{μ3-C(SiMe3)=C(Me)C=C(SiMe3)=C(Me)C=C(SiMe3)R} (2a: R=Me;3a: R=Bun). The dienediyl ligand in these complexes is formed by alkyne-vinylidene coupling, with vinylidene generated in the course of reaction from the alkyne molecule by the acetylene-vinylidene rearrangement involving a 1,2-shift of the Me3Si group. The structure of cluster3a was determined by X-ray structural analysis. The dienediyl ligand is coordinated to three metal atoms of the cluster framework by two π-ethylene bonds with two osmium atoms and two σ-bonds with the third osmium atom with the formation of the osmacyclobutene moiety. The1H and13C NMR study of13CO-enriched samples of clusters2a and3a revealed the stereochemical nonrigidity of these molecules due to the exchange of the hydrocarbon and carbonyl ligands.