Iridium-catalysed branched-selective hydroacylation of 1,3-dienes with salicylaldehydes

Herein, we report an iridium-catalyzed branched-selective hydroacylation of 1-aryl 1,3-dienes with salicylaldehydes under mild conditions with no need of phosphine ligands. With this protocol, a series of alpha-branched beta,gamma-unsaturated o-hydroxyacetophenones with biological potentials were synthesized in high efficiency with excellent regioselectivities. When simple 1,3-butadiene or isoprene instead of 1-aryl 1,3-dienes were used, exclusive linear-selective hydroacylation products were obtained.

Automated summary

In this study, an iridium-catalyzed branched-selective hydroacylation of 1-aryl 1,3-dienes with salicylaldehydes was successfully conducted under mild conditions without the need for phosphine ligands. The protocol yielded a series of alpha-branched beta,gamma-unsaturated o-hydroxyacetophenones with biological potentials in high efficiency and excellent regioselectivities. Exclusive linear-selective hydroacylation products were obtained when simple 1,3-butadiene or isoprene were used instead of 1-aryl 1,3-dienes.