Remote control: stereoselective coordination of electron-deficient 2,2'-bipyridine ligands to Re(I) and Ir(III) cores.

Highly diastereoselective coordination of unsymmetrical cationic 2,2'-bipyridine ligands bearing a chiral amidinium substituent to [Re(CO)Cl] and [Ir(PhPy)] cores is reported. Binding strength and stereoselectivity have been correlated with the position of the amidinium group on the bipy. The 4-, 5- and 6-substituted ligands all produce -[Re(CO)(LH)Cl]X selectively, while only the 4-derivative gives preferred formation of Δ-[Ir(Phpy)(4-LH)](BF).