Molybdenum Complex-Catalyzed <i>N</i>-Alkylation of Bulky Primary and Secondary Amines

Aliphatic allylic amines are present in a large number of complex and pharmaceutically relevant molecules. The direct amination of allylic electrophiles serves as the most common method toward the preparation of these motifs. However, the use of feedstock reaction components (allyl alcohol and aliphatic amine) in these transformations remains a great challenge. Such a challenge primarily stems from the high Lewis basicity and large steric hindrance of aliphatic amines, in addition to the low reactivity of allylic alcohols. Herein, we report a general solution to these challenges. The developed protocol allows an efficient allylic amination of allyl alcohols with sterically bulky aliphatic amines in the presence of an inexpensive earth-abundant molybdenum complex. This simple and economic protocol also enables regioselective branched amination; the practicality of the reaction was shown in an efficient, scaled-up synthesis of several drugs.