Asymmetric Synthesis of 1,3-Diamines by Diastereoselective Reduction of Enantiopure <i>N</i>-<i>tert</i>-Butanesulfinylketimines: Unusual Directing Effects of the <i>ortho</i>-Substituent

Chiral, nonracemic 1,3-diamines were prepared in a highly diastereoselective reduction of diaryl N-tert-butanesulfinylketimines. Correlation between facial selectivity of the reduction and E or Z geometry of the starting ketimines suggests involvement of a cyclic transition state for the reduction. The ortho-substituent controls the geometry of N-tert-butanesulfinylketimines in the solid state and provides additional stabilization of the cyclic transition state.通过对二芳基N-叔丁基亚磺酰酮亚胺（diaryl N-tert-butanesulfinylketimines）进行高非对映选择性还原，可制备手性非消旋1,3-二胺。该还原反应的面选择性与起始酮亚胺的E或Z构型存在相关性，提示还原过程涉及环状过渡态。邻位取代基可调控固态下N-叔丁基亚磺酰酮亚胺的构型，并为环状过渡态提供额外稳定作用。