The development of catalytic oxidations using practical terminal oxidants such as molecular oxygen represents a central challenge in catalysis. Critical to the development of such catalysts with practical potential is a fundamental understanding of the mechanistic features which lead to a robust and selective catalytic system. Within this regard, our group has focused on the development of new Pd(II)-catalysts for various oxidation reactions wherein mechanistic analysis has played a vital role in catalyst and reaction design. This presentation will focus on palladium-catalyzed alkene functionalization reactions which we have designed and developed based on mechanistic insight. The scope and applications of these new processes will also be discussed.