Kumadakopplingar
Kumadakopplingar, also known as Kumada couplings, are a type of chemical reaction used in organic synthesis to form carbon-carbon bonds. They are named after the Japanese chemist Kenichi Kumada, who developed the method in the 1970s. The reaction involves the coupling of an organozinc compound with an organic halide, typically an aryl or vinyl halide, in the presence of a palladium catalyst. The reaction proceeds via a radical mechanism, where the palladium catalyst facilitates the transfer of a zinc radical to the organic halide, forming a new carbon-carbon bond. Kumadakopplingar are particularly useful for the synthesis of complex organic molecules, such as natural products and pharmaceuticals, due to their high selectivity and mild reaction conditions. The reaction is typically carried out in a solvent such as tetrahydrofuran (THF) or dimethylformamide (DMF) at room temperature or slightly elevated temperatures. The use of Kumadakopplingar has significantly expanded the scope of organic synthesis, enabling the construction of a wide range of carbon-carbon bonds that were previously difficult to access.