Combined radical and ionic approach for the enantioselective synthesis of β-functionalized amines from alcohols

Chiral amines are among the most important organic compounds and have widespread applications. Enantioselective construction of chiral amines is a major aim in organic synthesis. Among synthetic methods, direct functionalization of omnipresent C–H bonds with common organic nitrogen compounds represents one of the most attractive strategies. However, C–H amination strategies are largely limited to constructing a specific type of N-heterocycles or amine derivatives. To maximize the synthetic potential of asymmetric C–H amination, we report here an approach that unites the complementary reactivities of radical and ionic chemistry for streamlined synthesis of functionalized chiral amines. This synthesis merges the development of an enantioselective radical process for 1,5-C(sp3)–H amination of alkoxysulfonyl azides via Co(II)-based metalloradical catalysis with an enantiospecific ionic process for ring-opening of the resulting five-membered chiral sulfamidates by nucleophiles. Given that alkoxysulfonyl azides are derived from the corresponding alcohols, this approach offers a powerful synthetic tool for enantioselective β-C–H amination of common alcohols while converting the hydroxy group to other functionalities through formal nucleophilic substitution. Enantioselective C–H amination is an attractive strategy for the synthesis of chiral amines. Now, a combined radical and ionic approach has been developed for 1,2-difunctionalization of alcohols by merging enantioselective radical C–H amination with stereospecific nucleophilic ring-opening, enabling synthesis of β-functionalized chiral amines.