Homo coupling reactions of optically active binaphthalenes possessing several kinds of side chains under classical copper–amine conditions were investigated. The newly formed axis of the chirality was controlled under three different pathways as follows; for 1a, mechanism could be explained by epimerization of the axis along with diastereoselective crystallization (second order asymmetric transformation), for 1b, the axis chirality of 2b was directly induced in the coupling step (kinetic control) and in the case of 1d, the axis chirality should be controlled with the difference of thermodynamic stabilities of diastereomeric reaction intermediates. The second order asymmetric transformation was applicable to 8 mer to afford (S,S,S,S,S,S,S,S,S,S,S,S,S,S,S)-16 mer in 79% de and 78% yield.
