Macrocyclic Ferrocenyl–Bisimidazoline Palladacycle Dimers as Highly Active and Enantioselective Catalysts for the Aza‐Claisen Rearrangement of Z‐Configured N‐para‐Methoxyphenyl Trifluoroacetimidates

In just four steps from ferrocene, macrocyclic ferrocenyl bispalladacyles have been synthesized by using a diastereoselective biscyclopalladation reaction as the key step. The complexes not only possess a fascinating structure but are also the first highly active catalysts for the title reaction (see scheme), requiring as little as 0.1 mol % of catalyst for most of the substrates. Ts=toluene-4-sulfonyl.