Nitrogen-containing compounds are an essential motif in all disciplines of chemistry and the efficient synthesis of these frameworks is a highly sought-after goal. Presented here is a summary of recent efforts conducted by our group to develop radical-mediated amination strategies for the formal synthesis of primary amines from alkenes with exclusive anti-Markovnikov regioselectivity. We have found that N-hydroxyphthalimide is an effective reagent capable of supplying both the N and H atoms for alkene hydroamination in a group transfer radical addition-type mechanism. Furthermore, allyl-oxyphthalimide derivatives are similarly capable of radical group transfers and allow for the aminoallylation of an external alkene.

An intermolecular anti-Markovnikov hydroamination of alkenes has been developed using triethyl phosphite and N-hydroxyphthalimide. The process tolerates a wide range of alkenes, including vinyl ethers, silanes, and sulfides as well as electronically unbiased terminal and internal alkenes. The resultant N-alkylphthalimides can readily be transformed to the corresponding primary amines. Mechanistic probes indicate that the process is mediated via a phosphite promoted radical deoxygenation of N-hydroxyphthalimide to access phthalimidyl radicals.

Phenolic, lignin-derived substrates have emerged as desirable biorenewable chemical feedstocks for coupling reactions. A radical-mediated conversion of phenol derivatives to anilines is reported, using unfunctionalized hydroxamic acids as the N-centered radical source. The applicability of this triethyl phosphite mediated O-atom transfer approach, which tolerates a range of steric and electronic demands to naturally occurring phenols and lignin models, has been demonstrated in this work to access the corresponding aniline derivatives.