Radical Allylation and Benzylation of N ‐Benzyl Ketimines with Allyl‐Bpins or 4‐Benzyl Hantzsch Esters Through Hydrogen Atom Transfer (HAT)/Photoredox Process

In the past decade, the functionalization of N ‐benzyl ketimines has emerged as an attractive way toward the concise synthesis of α ‐substituted benzyl amine derivatives. Besides the traditional nucleophilic substitution with 2‐azaallyl anions to alkyl halides, recent progress has focused on CC bond formation via 2‐azaallyl radicals. These processes require the use of a strong base to convert N ‐benzyl ketimines to 2‐azaallyl anions, which perform as organic super‐electron‐donors, and only electrophiles can be used as the radical precursors for the coupling partners. Herein, we present the photoinduced benzylation and allylation of N ‐benzyl ketimines with nucleophiles as the radical precursors, such as allyl Bpins (pinacol boronic esters) and 4‐benzyl Hantzsch esters. Lauroyl peroxide is employed to mediate 2‐azaallyl radical generation via a hydrogen atom transfer (HAT) process and furnish the redox cycle of the photocatalyst.