Bifunctional iron-catalyzed alkyne Z-selective hydroalkylation and tandem Z-E inversion via radical molding and flipping

The challenging synthesis of thermodynamic-unfavored cis-olefins through catalytic cross-coupling reactions requires the synergistic interaction of substrate-activating units and configuration-regulating catalysts. Successfully hitting these two birds with one stone, we herein develop a convenient photoredox access to Z-alkenes from alkynes and light alkanes with a bifunctional iron-catalyzed system possessing both C(sp3)-H activation and configuration-controlling abilities. The protocol exhibits 100% atom utilization, mild conditions, a broad substrate scope, and compatibility with multitudinous functional groups. The detailed reaction mechanism and the origin of geometry regulation are well investigated by experimental and computational studies. Progressively, a catalytic amount of diaryl disulfides is introduced for consecutive photoinduced Z-E isomerization via reversible radical addition and flipping. Big steric hindrance substituents assembled on the disulfide emerge necessity for suppressing double-bond migration. This tandem strategy paves a promising way for stereoselective alkene construction and will bring significant inspiration for the development of transition metal photocatalysis.

Yongqiang Zhang, Dongmin Fu, Ziyang Chen, Rongqi Cui, Wenlong He, Hongyao Wang, Jiajin Chen, Yufei Chen, Shi-Jun Li, Yu Lan, Chunying Duan, Yunhe Jin