Alkynes are versatile and valuable synthetic precursors in a variety of organic transformations and have found tremendous applications in materials science and pharmaceutical chemistry. In recent years, there has been a tremendous growth in the development of transitionmetal catalyzed organic transformations by alkynes coupling reactions such as ring constructions (carbocycles and heterocycles), hydroarylation and hydroamination. This thesis describes the development of new transition metal catalyst for alkyne coupling reactions. The results are highlighted by chemoselective coupling between internal alkynes and N-H aromatic ketimines to synthesize indenamine, dihydroisoquinoline, and 2-aza-1,3-butadiene derivatives. Chapter 1 introduces background for alkyne coupling reactions towards hydrometalation, hydroarylation and hydroamination. Also this chapter provides new strategies developed towards C-H activation and hydroamination by using late transition metal catalysts. Chapter 2 describes catalytic development of rhodium catalyzed redox-neutral [4+2] annulation of N-H aromatic ketimines and alkynes to synthesize multi-substituted 3,4- dihydroisoquinolines (DHIQs) in high chemo-selectivity over competing annulation processes, exclusive cis-diastereoselectivity, and distinct regioselectivity for alkyne addition. Chapter 3 describes development of earth abundant metal nickel as the catalyst for the Nickel (0)/NHC-based catalyst system for alkyne hydroimination with aromatic N−H ketimines as N-nucleophiles. To demonstrate the potential of current method for practical synthesis, we also carried out a gram-scale alkyne hydroimination with benzophenone imine. Chapter 4 describes catalyst development for oxidative [4+2] imine/alkyne annulation with unconventional regioselectivity. Even though there are numerous methods towards the synthesis of isoquinoline derivative here in this chapter we proposed a different pathway for C-N bond formation compared to other reported methods. In spite of moderate yields for the unsymmetrical alkynes the regioselectivity is different from other reported isoquinoline products by oxidative [4+2] annulations. Chapter 5 describes about Ni/NHC catalyst development towards stereoselective semihydrogenation of alkynes by usig simple alcohol, isopropanol as the hydrogen source. Here we report new Ni-NHC complexes derived from Ni(0)-mediated facile C−H activation at the methyl position of IPr, one of the most commonly used NHC ligands in nickel catalysis. Results from stoichiometric transformations suggest that such cyclometalation provides a low-energy access to NHC-ligated Ni(II) hydride species that are envisioned as key reactive intermediates in many catalytic processes.