Stereodivergent Alkylation of Unstrained C(sp³)─C(sp³) Bonds

Asymmetric functionalization of C─C σ bond is a straightforward way to edit molecule backbones but heavily relies on strained rings. The related process with unstrained structure is highly challenging, and only several cases are reported. However, these examples can just achieve related enantiomers through C─C σ bond activation. The stereodivergent C─C σ bond functionalization for precise access to all stereoisomers is unknown. Here we have established two catalytic systems to show the feasibility of unstrained C─C σ bond functionalization as an efficient pathway in stereodivergent synthesis. Both unnatural amino acid derivatives bearing two vicinal stereocenters and carbonyl compounds containing a tertiary fluoride are constructed in good yields with high diastereo- and enantioselectivities. Stereodivergent access to all these chiral skeletons is demonstrated possible with simple dictation of ligand configurations. Mechanistic studies unveil the resolution pathway of racemic allyl substrates through diene formation instead of typical metal interconversion and C─C formation as rate-determining step.