In this review, the results of studies on new methodology for bond activation by using transition metal complexes are described, in order to realize the expeditious and selective synthesis of organic compounds. Carbon-carbon bond formation reactions, accompanying with cleavage of unactivated bonds such as carbon-carbon, carbon-boron, and carbon-silicon bonds, are reported. This review involves, for examples, the new synthetic methodology to introduce both cyano and ester groups (cyanoesterification) via the C-C bond activation, regio- and stereoselective synthesis multi-substituted olefins mediated a zirconocene complex via the C-B bond activation, and cross-coupling reaction of alkynylsilanes activated by a copper salt via the C-Si bond cleavage. Each reaction can be applicable to synthesis of functional molecules such as opto-electronic materials, an anti-cancer agent, and liquid crystalline compounds.