CERC3-Sustainability - Kirschning-Kunz-Kappe: Microwave accelerated heterogeneous catalysis in flowthrough reactors

In the context of chemistry, sustainability deals with the question of how syntheses can be performed safely with minimum input of energy and other resources and at the same time reducing waste and byproducts. Flow-through systems with immobilized and recyclable multi-catalyst systems can be regarded as ideal contributions in this field. Hence, this is the main focus of the project proposal. The project is initiated by a novel way of preparing micro-dispersed metal(0) on a polymer surface. Reduction of ion exchange-bound metals such as palladate is the key step of this process. This procedure generates a broadly usable catalytic system on a polymeric surface which is made up of two different active centers in close proximity. These active centers are supposed to play different roles in multi catalyst systems. This new heterogeneous system will be used to study hydrogenations, Pd-catalyzed C-C-cross-coupling reactions and formation of C-N bonds. The additional feature of this project is the incorporation of this immobilized chemical system into a novel microreactor which contains a new monolithic glass/polymer composite material ideally designed for flow-through processes. This micro-structured reactor allows to perform reactions in solution with minimum purification. In order to overcome kinetic restrictions associated with this biphasic system, the flow-through reactor will be implemented into a microwave field. The polar ion-exchange matrix and the microdispersed metal (0) species can be selectively activated in the microwave field thus creating "hotspots" at the location where the reaction takes place. The project combines a number of new important technologies in order to find optimal conditions for carrying out multistep transformations in a rapid, safe and highly efficient way, thereby reducing the workup procedure to a minimum. It is the goal of this study to provide a new sustainable technological platform for industrial applications.

In the context of chemistry, sustainability deals with the question of how syntheses can be performed safely with minimum input of energy and other resources and at the same time reducing waste and byproducts. Flow-through systems with immobilized and recyclable multi-catalyst systems can be regarded as ideal contributions in this field. Hence, this is the main focus of the project proposal. The project is initiated by a novel way of preparing micro-dispersed metal(0) on a polymer surface. Reduction of ion exchange-bound metals such as palladate is the key step of this process. This procedure generates a broadly usable catalytic system on a polymeric surface which is made up of two different active centers in close proximity. These active centers are supposed to play different roles in multi catalyst systems. This new heterogeneous system will be used to study hydrogenations, Pd-catalyzed C-C-cross-coupling reactions and formation of C-N bonds. The additional feature of this project is the incorporation of this immobilized chemical system into a novel microreactor which contains a new monolithic glass/polymer composite material ideally designed for flow-through processes. This micro-structured reactor allows to perform reactions in solution with minimum purification. In order to overcome kinetic restrictions associated with this biphasic system, the flow-through reactor will be implemented into a microwave field. The polar ion-exchange matrix and the microdispersed metal (0) species can be selectively activated in the microwave field thus creating "hotspots" at the location where the reaction takes place. The project combines a number of new important technologies in order to find optimal conditions for carrying out multistep transformations in a rapid, safe and highly efficient way, thereby reducing the workup procedure to a minimum. It is the goal of this study to provide a new sustainable technological platform for industrial applications.