On the enantioselective rhodium-catalyzed enyne cyclization

Several chiral ligands were tested in the enantioselective rhodium-catalyzed enyne cyclization, but none gave results comparable to the BINAP ligand. Among the tested catalyst precursors the soon to be commercially available [(COD)Rh(H2O)(2)]CF3SO3 complex is an interesting alternative to the [(COD)-RhCl](2) because it did not need the activation with silver ions. A new stereogenic and 1,2-disubstituted double bond was formed in the product 12, the latter was proved to have an (E)-configuration. A new product, the 1,3-diene 16 was observed at higher temperatures. In the presence of an (E)-configurated double bond in the starting material, the reaction completely failed.