Porphyrins: ''Smart Catalysts'' for the Synthesis of High-Added Value Compounds

The chemical industry needs to develop clean, efficient and selective procedures to synthesize high added-value fine chemicals and catalytic processes provide powerful tools to reach this goal. The key point to perform sustainable transformations is the choice of catalytic systems that show selectivity, activity and stability, resulting in high TOF (turnover frequency) and TON (turnover number), not to mention an efficient catalyst must be easily recovered and recycled. Based on these concepts, the employment of metal porphyrin complexes in catalysis is constantly growing due to the enormous potential of this class of molecules. Metal porphyrins are robust and their chemo-physical properties can easily be fine-tuned by varying their molecular structure to allow the use of these catalysts to selectively promote a large number of organic transformations. We have studied in depth the employment of metal porphyrin complexes to create new C-N and C-C bonds by using organic azides[1] and diazo compounds[2] and more recently we have focused our interest also on the synthesis of high-added value fine chemicals by using waste, such as CO2, as starting material by applying 100% atom economic procedures.[3] We will present different synthetic protocols which will also be discussed from a mechanistic point of view based on spectroscopic and theoretical studies and the identification of active intermediates. It is important to point out that mechanistic speculations are fundamental to optimize the catalytic performance of porphyrin complexes and spread out their applications in other fields of homogeneous catalysis