Iron-Catalyzed Carboamination of Olefins: Synthesis of Amines and Disubstituted β‑Amino Acids

Intermolecular carboamination of
olefins with general alkyl groups
is an unsolved problem. Diastereoselective carboamination of acyclic
olefins represents an additional challenge in intermolecular carboaminations.
We have developed a general alkylamination of vinylarenes and the
unprecedented diastereoselective anti-carboamination
of unsaturated esters, generating amines and unnatural β-amino
acids. This alkylamination is enabled by difunctional alkylating reagents
and the iron catalyst. Alkyl diacyl peroxides, readily synthesized
from aliphatic acids, serve as both alkylating reagents and internal
oxidizing agents. A computational study suggests that addition of
a nitrile to the carbocation is the diastereoselectivity-determining
step, and hyperconjugation is proposed to account for the highly diastereoselective anti-carboamination.