Transition metal carbene complexes have attracted a great deal of attention not only as a novel class of compounds but also as intermediates for organic synthesis. A series of transition metal cyclic dioxy and aminooxy carbene complexes were synthesized from ethylene oxide, and metal carbonyls catalyzed by bromide;Part of an effort in this thesis is to study the conversion of metal-dioxy carbene complexes into organic compounds and the synthesis of new dioxy and aminooxy carbene complexes. Investigations of reactions of the dioxycarbene ligand show that Fe(CO)[subscript]4(=[overline] COCH[subscript]2 CH[subscript]2 O) decomposes with evolution of CO[subscript]2 and ethylene, but reacts with oxidizing agents, Me[subscript]3NO or O[subscript]2, to produce ethylene carbonate. The reaction of Fe(CO)[subscript]4(=[overline] COCH[subscript]2 CH[subscript]2 O) with H[subscript]2 gas gives 1,3-dioxolane. Also, synthesis of Os[subscript]3(CO)[subscript]11(=[overline] COCH[subscript]2 CH[subscript]2 O), Os[subscript]3(CO)[subscript]10(=[overline] COCH[subscript]2 CH[subscript]2 O)[subscript]2 and derivatives of Re(CO)[subscript]4(Br)(=[overline] COCH[subscript]2 CH[subscript]2 NH) are reported. The x-ray structural characterization of a bis-dioxycarbene complex, Os[subscript]3(CO)[subscript]10(=[overline] COCH[subscript]2 CH[subscript]2 O)[subscript]2 is presented;The other part of this thesis deals with substitution reactions of metal carbonyls. Traditionally, such reactions are carried out under thermal and/or photochemical conditions; despite several commonly observed problems: low yields, mixtures of mono- to multi-substituted products and long reaction time. Here, two Pt(O) compounds, Pt(PPh[subscript]3)[subscript]4 and Pt(dibenzylideneacetone)[subscript]2 are reported to catalyze a variety of phosphine substitution of CO reactions in mono-, di-, and tri-nuclear metal carbonyl complexes. The benefits of these two Pt(O) catalyzed substitution reactions are high yields, almost quantitative recovery of the catalyst and only mono-substituted products.