Rhodium and Palladium Catalysed Domino Reactions of Alkenyl Pyridines and Alkenyl Pyrazines

• Main Author: Friedman, Adam Alexander
• Other Authors: Lautens, Mark
• Language: en_ca
• Published: 2013
• Subjects: Rhodium; Palladium; Arylation; C-O Coupling; Domino Catalysis; Heterocycles; Multi-Catalytic Reactions; 0490
• Online Access: http://hdl.handle.net/1807/42841

Domino catalysis is an ideal strategy in the synthesis of heterocyclic scaffolds, as multiple bonds can be formed under a single set of reaction conditions. In this work, we present the development of two novel domino processes which afford access to aza-analogues of the dihydrodibenzoxepine motif. Careful optimisation revealed that the Rh catalysed hydroarylation proceeds under mild conditions as compared to the C-O coupling. Furthermore, Pd was not required for the C-O bond formation when using alkenyl pyrazines as substrates. Variation of the substituents on both the heterocycle and on the boronic ester provided insight into the structural features required for successful domino reaction, and a stepwise protocol was developed for incompatible substrates. We have also developed the first multi-metal, multi-ligand domino reaction featuring both a chiral and achiral ligand in the same pot, still leading to an enantioenriched product.