Asymmetric intramolecular hydrofunctionalization of tertiary allylic alcohols is described. This metal hydride-mediated catalytic radical−polar crossover reaction delivers corresponding epoxides in good to high enantioselectivity and constitutes the first example of asymmetric hydrogen atom transfer-initiated process. A series of modified cobalt salen complexes has proven optimal for achieving good efficiency and asymmetric induction. Experimental data suggest that cationic cobalt complexes may be involved in the enantiodetermining step, where cation−π interactions in the catalyst contribute to the asymmetric induction.

Radical−polar crossover hydrofunctionalizations of tertiary allylic alcohols are described. Depending on the structure of the catalyst, corresponding epoxides or semipinacol rearrangement products are selectively obtained in good yields. Experimental evidence points to the participation of alkylcobalt complexes as electrophilic intermediates.

First-row transition metal catalysis offers a cheaper, more environmentally sustainable alternative to second- and third-row transition metal catalysts. Nickel has shown great promise as a tool for the borylation of unsaturated compounds to yield boronic esters, but Markovnikov-selective hydroborations of simple styrenes have not been well-explored. Herein, we report the synthesis of benzyl boronic esters via nickel-catalyzed hydroboration of styrenes using a heteroleptic N-heterocyclic carbene (NHC)–phosphine nickel complex, IMes­(Cy3P)­NiCl2. The IMes­(Cy3P)­NiCl2 complex displays a broad substrate scope and maintains the integrity of yield and regioselectivity when challenged with substrates bearing increased steric hindrance. The heteroleptic complexes also tolerate both electron-withdrawing and -donating groups, in contrast to traditional bis-phosphine and Ni(0) complexes.

A catalytic radical-polar crossover Ritter reaction is described. The transformation proceeds under acid-free conditions and tolerates a variety of functional groups. The catalyst design overcomes limitations in the substitution pattern of starting materials and enables hydroamidation of a diverse range of alkenes. Formation of hydrogen contributes to the background consumption of reductant and oxidant and competes with the desired pathway, pointing to a mechanistic link between hydrogen atom transfer-initiated organic reactions and hydrogen evolution catalysis.

Asymmetric intramolecular hydrofunctionalization of tertiary allylic alcohols is described. This metal hydride-mediated catalytic radical-polar crossover reaction delivers corresponding epoxides in good to high enantioselectivity and constitutes the first example of asymmetric hydrogen atom transfer-initiated process. A series of modified cobalt salen complexes has proven optimal for achieving good efficiency and asymmetric induction. Experimental data suggest that cationic cobalt complexes are involved in enantio-determining step, where cation–π interactions in the catalyst contribute to the asymmetric induction.