On the basis of recent PI’s findings, this project aims to take advantage of the Cu(I)/Cu(III) redox pair chemistry to perform a wide range of copper catalyzed organic transformations under very mild conditions, i.e. aryl-heteroatom cross coupling, aryl-halide exchange, aryl fluorination, and direct C-H functionalization reactions. The development of new sustainable methodologies alternative to Pd-based ones will make a tremendous impact into routine organic synthesis procedures and into selective late-stage modification of pharmaceuticals. Pd is the metal of choice in most of aryl-heteroatom coupling reactions but toxicity and intrinsic cost are serious drawbacks for production of drugs. Cu has become a real alternative to Pd due to low cost, low toxicity and continuously increasing efficiencies of Cu-catalyzed coupling reactions. However, the mechanistic details for Cu-based processes are still poorly understood and experimental conditions are far from sustainable. Fundamental Cu(I)/Cu(III) oxidative addition and reductive elimination steps are often invoked but remained unobserved until the recent well-defined aryl-Cu(III)-halide key species reported by the PI. An initial goal consists in the in-depth mechanistic comprehension of Cu(I)/Cu(III) redox steps in a series of electronically and structurally tuned aryl-halide model systems. A subsequent goal will be the exploration of tridentate pincer-like systems in aryl-heteroatom coupling reactions with simple aryl-halides, aiming to find milder and efficient catalysts by redirecting mechanistic pathways towards the stabilization of aryl-Cu(III) species. Exploitation of Cu(I)/Cu(III) redox chemistry in direct C-H functionalization will also be undertaken. Exploration of analogous M(I)/M(III) redox chemistry with Au and Ag will be performed in order to gain a complete mechanistic picture of these reactions mediated by coinage metals, building on the necessary knowledge to design future generations of catalysts.