Pd-Catalyzed Enantioselective Double C–H Activation and Transmetalation: Synthesis of 2‑Heteroaryl/aryl-Ferrocenealdehydes

Synthesis of heterocycle-derived chiral ferrocene formaldehydes
opens a new avenue for planar chiral ligands, catalysts, and chiral
materials. Herein, PdII/MPAA catalyzed enantioselective
double C–H activation, an arylation-oxidative deamination strategy,
leads to a step-economical synthetic route for regioselective, monoselective,
and enantioselective new heterocycle-substituted chiral ferrocene
formaldehydes. The developed methodology is quite general to provide
indolizinyl, indolyl, pyrrolyl, furanyl, thiophenyl, oxazolyl, thiazolyl,
and aryl-substituted platform ferrocene formaldehydes with up to 60%
yield and 97:3 er.