trans-Cyclohexane-1,2-diamine Is a Weak Director of Absolute Helicity in Chiral Nickel−Salen Complexes

The interconversion between helical diastereomers of nickel−salen-based foldamers can be observed on a NMR time scale. Such complexes provide quantitative information about the propensity of different elements of central chirality to control the absolute sense of folding. trans-Cyclohexane-1,2-diaminea common component of chiral salen catalystsis a surprisingly weak director of absolute helicity in nickel−salen foldamers. Implications for asymmetric catalysis are discussed.