This review highlights catalytic 1,4-difunctionalization of 1,3-enynes for synthesizing functionalized allenes. It covers photoredox and electrochemical strategies, emphasizing their selectivity, mild conditions, and future sustainable directions.
This review article summarizes the visible light mediated synthesis of allenes from substrates like 1,3-enynes, propargylic carbonates, homopropargylic alcohols, propargylic oxalates, alkynyl diazo compounds, and terminal alkynyl aziridines.
A copper-catalyzed 1,4-alkylcyanation of CF3-containing 1,3-enynes with fused azabicyclic peroxides and TMSCN is presented, providing an efficient route to allenes containing CN and succinimide fragments via selective C–C bond cleavage.
A photoredox/copper catalyzed three-component reaction of 1,3-enyne, difluoroalkylating reagent, and TMSCN has been developed. A diversity of difluoroalkylated allenes were generated in good yields and regioselectivity.
NHC and photocatalysis dual-catalyzed mono/difluoromethylative acylation of 1,3-enynes was realized, providing fluormethyl-substituted allenyl ketones. SO2 might play a critical role in achieving high reactivity and selectivity.