Diastereoselective Bis-Cyclopalladation of Ferrocene-1,1′-diyl Bis-Imidazolines: Translation of Central via Axial into Planar Chirality

An axially chiral reactive precursora trans-configured Pd(II) chelate complextoward the planar chiral bis-palladacycle FBIP-Cl, which was recently shown to be an excellent enantioselective catalyst for both aza-Claisen rearrangements and direct Michael additions, has been identified and allows us to explain the stereochemical outcome of the first reported direct diastereoselective bis-cyclopalladation. In contrast to the trans-configured chelate complex, its cis-configured counterpart turned out to be a dead end under the initial cyclopalladation conditions and required harsher conditions for C−H activation.