The chemistry of the reaction of Os3(CO)10(NCCH3)2 with representatives of unsaturated amides and esters, RCOCHCH2 (R=(CH3)2N, CH3O) has been investigated. In these reactions, it has been observed that a CH bond on the β-carbon atom is readily activated by triosmium carbonyl clusters. The activation of β-carbon C-H bond in unsaturated amides and esters provides a robust platform for studying multicenter C-H bond transformations and for C-C bond formation via hydrogen shift and CO insertion processes. In this work, proposed mechanistic approaches have been taken in order to better understand and study the relationship between the characterized species. In addition, a few non-identified species have been predicted to exist. Furthermore, recommendations on how this work can be further studied and improved have been made. A series of activated unsaturated amides and esters: Os2(CO)6(µ-H)(µ O=C(N(CH3)2)CHCH), 1, Os4(CO)12(µ- O=C(N(CH3)2)CHCH)2, 2, Os3(CO)9(µ-O=C(N(CH3)2)CH2CHCCHC(N(CH3)2)=O), 3, Os3(CO)8(µ-O=C(N(CH3)2)CHCH)2, 4, Os6(CO)20(µ-H)(µ-O=C(N(CH3)2) CHCH), 5, HOs3(CO)10(µ-O=C(N(CH3)2)CHCH), 6, Os5(CO)15(µ-O=C(N(CH3)2)CHCH)2, 7, and Os3(CO)9(µ-H)(µ-O=C(OCH3)CHCH), 8, were synthesized and isolated. They are described in Chapter 1. Each of the new compounds has been characterized by FT-IR, NMR (1H), mass-spectra and single crystal X-ray diffraction analysis
