The synthesis of conjugated polyynes is a genuine scientific challenge nowadays. Although several methods have been reported over the last decades, diverse and efficient methods for the synthesis of compounds bearing more than two conjugated CC triple bonds remain inadequate. In this project, we propose to use alkyne metathesis as a new "soft" and expedient method for the synthesis of triynes, tetraynes, pentaynes and beyond. On the basis of promising preliminary results obtained with triynes, we proposed new catalysts that are designed to control the selectivity towards the targeted polyynes. After evaluating the scope and limitations of our methodology, it will be applied to the synthesis of polyynes that are currently inaccessible with known methods in the field of physical organic chemistry. An ultimate goal of the project is the synthesis of C24, a cyclic allotrope of carbon.