Our catalysis program is focused on a comprehensive study of reactivity of electron rich alkynes. We believe that this general class of compounds holds an excellent potential for the development of an arsenal of new catalytic processes of significant conceptual and practical utility. Indeed, we have developed the silver-catalyzed [2+2] cycloaddition of siloxy alkynes with a range of unsaturated carbonyl compounds, and the Bronsted acid-mediated cyclizations of siloxy alkynes with unactivated arenes and alkenes. We also discovered a novel gold-catalyzed skeletal reorganization of acyclic siloxy enynes to siloxy cyclohexadienes, which proceeds via a series of unprecedented 1,2-alkyl shifts. Most recently, we developed a series of new Bronsted acid-mediated siloxy diyne cyclizations, which proceed with concomitant formation of C-Hal bonds as a result of halide abstraction from a halocarbon by the intermediate alkenyl cation. We believe that the metal- or proton-based activation of siloxy alkynes is a critical mechanistic aspect of each of these reactions. Our current efforts are aimed at further expansion of the arsenal of reactivity of electron rich alkynes and applications of these methods to construction of complex natural products and diverse chemical libraries.