Zinc-mediated regiodiverse synthesis of vinyl bromide derivatives and their in situ palladium-catalysed cross-coupling reactions

Article abstract of DOI:10.1055/s-0033-1339616

The synthesis of vinyl bromide derivatives was realised by a zinc-mediated addition of a benzylic bromide to a terminal alkyne. The geometry of the C=C bond is dependent on the amount of zinc powder applied. When 5 mol% of Zn is used, the Z-configured vinyl bromide is generated while with 150 mol% the E-geometry is obtained predominantly. In a three-component one-pot reaction, the in situ generated vinyl bromides were reacted further in a palladium-catalysed Suzuki cross-coupling reaction utilizing aromatic boronic acids to obtain trisubstituted double bonds in good overall yields. The reactions were conducted on a 5-20 mmol scale to visualise that the reactions are also capable of generating larger amounts of products. Georg Thieme Verlag Stuttgart New York.