Photoredox/nickel dual-catalyzed deaminative cross-electrophile for allenylic alkylation with non-activated alkyl katritzky salts

Abstract

Herein, we report the first allenylic alkylation with bench-stable aliphatic amine-derived Katritzky salts via photoredox/nickel dual-catalyzed reductive deaminative cross-electrophile coupling. Non-activated alkyls were efficiently introduced. Abundant substrate sources make this reaction a suitable alternative and widely applicable as it avoids the limitations of rare allenylic alkylations with amino acid derivatives. Meanwhile, the successful involvement of alkyl propargylic electrophiles represents a rare but direct approach for synthesizing polyalkylated allenes without organometallic reagents. Mechanistically, a hypothetical radical–radical coupling between alkyl radical and hybrid allenyl-Ni(I) radical species is proposed.