Synthesis of the Conjugated Tetraene Acid Side Chain of Mycolactone E by Suzuki–Miyaura Cross‐Coupling Reaction of Alkenyl Boronates (Eur. J. Org. Chem. 2/2014)

The cover picture shows a snapshot of the landscape of Ninghai in the east coast of China. The cross-coupling reaction of a trisubstituted alkenyl bromide with a trisubstituted alkenyl boronate proceeds smoothly with a Pd(OAc)2–Aphos-Y catalyst system under conditions (35 °C, THF/H2O, K3PO43H2O) similar to the natural surrounding environment. The hemilabile Aphos-Y ligand is known to form P,O-chelating and P-monodentate complexes with palladium(0) and palladium(II) species, which facilitate various steps in the catalytic cycle. The mild coupling conditions, without the use of a highly toxic TlI base, renders the Pd(OAc)2–Aphos-Y catalyst system promising for polyene natural product total synthesis. Details are discussed in the article by Y. Wang and W.-M. Dai on p. 323 ff.