N-heterocyclic palladium carbene complexes as catalysts in the Mizoroki-Heck reaction

INOR 47

Maria A. Taige and Thomas Strassner, thomas.strassner@chemie.tu-dresden.de. Physical Organic Chemistry, TU Dresden, Mommsenstrasse 13, Dresden, 01062, Germany
Owing to the high stability of metal complexes of N-heterocyclic carbenes (NHCs) towards heat, moisture and oxygen, they have long been the subject of catalytic studies. The Mizoroki-Heck reaction has an enormous synthetic potential for generating carbon-carbon bonds. In the Heck coupling of iodobenzene with styrene very high TONs could already be observed, while the search for catalysts with high TONs for the coupling of bromo- and especially chloroarenes with olefins is ongoing. We therefore studied the performance of palladium complexes of NHCs as catalysts for the Heck coupling of styrene with bromo- and chloroarenes in dimethylacetamide in the presence of sodium acetate. During our studies we observed that our new palladium complexes of NHCs are catalyzing the Mizoroki-Heck reaction with good TONs at moderate reaction temperatures even for difficult substrates like chloroacetophenone.