Photo-induced nickel-mediated cross-electrophile coupling for alkylated allenes via electron donor-acceptor complexes

Herein, a highly regioselective alkylation of propargylic carbonates for trisubstituted allenes with alkyl N-hydroxyphthalimide (NHP) esters was developed via a nickel-mediated radical cross-electrophile coupling process. Electron donor-acceptor (EDA) complex photoactivation strategies have emerged as a versatile way for alkyl radicals. This method features mild conditions and a broad substrate scope and the involvement of primary alkyl radicals represents the first direct approach for primary alkylated allenes. Preliminary mechanistic studies indicated that this transformation proceeded through a radical-radical coupling process.

Automated summary

A highly selective alkylation method using nickel-mediated radical cross-electrophile coupling reaction was developed for trisubstituted allenes with alkyl N-hydroxyphthalimide (NHP) esters. This method provides mild conditions, broad substrate scope, and a direct approach for the introduction of primary alkyl groups. Preliminary mechanistic studies indicate that the reaction proceeds through radical-radical coupling process.