The present thesis describes syntheses, structural studies, and catalytic reactivity of
new non-classical silane complexes of ruthenium and iron. The ruthenium complexes
CpRu(PPri3)CI(T]2-HSiR3) (1) (SiR3 = SiCh (a), SiClzMe (b), SiCIMe2 (c), SiH2Ph (d),
SiMe2Ph (e» were prepared by reactions of the new unsaturated complex
CpRu(PPri3)CI with silanes. According to NMR studies and X-ray analyses, the
complexes la-c exhibit unusual simultaneous Si··· H and Si··· CI-Ru interactions. The
complex CpRu(PPri3)CI was also used for the preparation of the first examples of late
transition metal agostic silylamido complexes CpRu(PPri3)(N(T]2-HSiMe2)R) (2) (R=
Ar or But), which were characterized by NMR spectroscopy. The iron complexes
CpFe(PMePri2)H2(SiR3) (3) (SiR3 = SiCh (a), SiClzMe (b), SiCIMe2 (c), SiH2Ph (d),
SiMe2Ph (e» were synthesized by the reaction of the new borohydride iron complex
CpFe(PMePri2)(B~) with silanes in the presence NEt3. The complexes 3 exhibit
unprecedented two simultaneous and equivalent Si··· H interactions, which was
confirmed by X-ray analyses and DFT calculations. A series of cationic ruthenium
complexes [CpRu(PR3)(CH3CN)(112-HSiR'3)]BAF (PR3 = PPri
3 (4), PPh3 (5); SiR'3 =
SiCh (a), SiClzMe (b), SiClMe2 (c), SiH2Ph (d), SiMe2Ph (e» was obtained by
substitution of one of the labile acetonitrile ligands in [CpRu(PR3)(CH3CNh]BAF
with sHanes. Analogous complexes [TpRu(PR3)(CH3CN)(T]2 -HSiR' 3)]BAF (5) were
obtained by the reaction of TpRu(PR3)(CH3CN)CI with LiBAF in the presence of
silanes. The complexes 4-5 were characterized by NMR spectroscopy, and the
observed coupling constants J(Si-H) allowed us to estimate the extent of Si-H bond
activation in these compounds.
The catalytic activity in hydrosilylation reactions of all of the above complexes was
examined. The most promising results were achieved with the cationic ruthenium precatalyst [CpRu(PPri3)(CH3CN)2t (6). Complex 6 shows good to excellent catalytic
activity in the hydrosilylation of carbonyls, dehydrogenative coupling of silanes with
alcohols, amines, acids, and reduction of acid chlorides. We also discovered very
selective reduction of nitriles and pyridines into the corresponding N-silyl imines and
l,4-dihydropyridines, respectively, at room temperature with the possibility of
catalyst recycling. These chemoselective catalytic methods have no analogues in the
literature. The reactions were proposed to proceed via an ionic mechanism with
intermediate formation of the silane a-complexes 4