Manganese‐Catalyzed Asymmetric Formal Hydroamination of Allylic Alcohols: A Remarkable Macrocyclic Ligand Effect

Abstract

A unique family of chiral peraza N6‐macrocyclic ligands, which are conformationally rigid and have a tunable saddle‐shaped cavity, is described. Utilizing their manganese(I) complexes, the first example of earth‐abundant transition metal‐catalyzed asymmetric formal anti‐Markovnikov hydroamination of allylic alcohols was realized, providing a practical access to synthetically important chiral γ‐amino alcohols in excellent yields and enantioselectivities (up to 99 % yield and 98 % ee). The single‐crystal structure of a MnI complex indicates that the manganese atom coordinates with the chiral dialkylamine moiety in a bidentate fashion. Further DFT calculations revealed that five of the six nitrogen atoms in the ligand were engaged in multiple noncovalent interactions with Mn, an isopropanol molecule, and a β‐amino ketone intermediate via coordination, hydrogen bonding, and/or CH⋅⋅⋅π interactions in the transition state, showing a remarkable role of the macrocyclic framework.