Enantioselective Construction of 1H‑Isoindoles Containing Tri- and Difluoromethylated Quaternary
Stereogenic Centers via Palladium-Catalyzed C–H Bond Imidoylation
An intermolecular enantioselective
synthesis of 1H-isoindoles containing tri- and difluoromethylated
quaternary stereogenic
centers through a palladium-catalyzed desymmetric C–H bond
imidoylation has been developed. α,α-Diaryl tri- and difluoroethylated
isocyanides acted as powerful precursors of chiral 1H-isoindoles, in which the fluoroalkyl group was proven to play a
crucial role in both the stereochemistry and reaction efficiency.
In addition, an allene insertion cascade was realized, offering rapid
access to diverse C1-tethered bis-heterocyclic scaffolds with good
yields and high enantioselectivities. The reactions proceeded smoothly
under mild conditions with low catalyst loadings.