This thesis is subdivided into two principal parts. The first part is focussed on the synthesis of pyrazole derivatives of agrochemical relevance. Indeed, the pyrazole nucleus is found in numerous compounds possessing interesting biological properties, and notably antifungal activities. Various convergent approaches to diversely substituted pyrazoles have therefore been developed by means of site-selective palladium-catalyzed cross-coupling reactions conducted sequentially on pyrazole scaffolds. In the second part, we have been involved in the synthesis of furopyridones as simplified analogues of natural compounds possessing antifungal activities such as Cladobotryal. Toward this end, various alkynylpyridones have been synthesizes and involved in diverse cyclization processes to access a series of furo[3,2-c]pyridin-4-ones, furo[3,2-c]pyridin-6-ones, and furo[2,3-b]pyridin-4-ones
