Catalytic Asymmetric Conjugate Addition of a Borylalkyl Copper Complex for Chiral Organoboronate Synthesis
作者:Won Jun Jang、Jaesook Yun
DOI:10.1002/anie.201909712
日期:2019.12.9
We report the catalytic enantioselectiveconjugateaddition of a borylalkyl copper nucleophile generated in situ from a 1,1-diborylmethane derivative to α,β-unsaturated diesters. In the presence of a chiral N-heterocyclic carbene (NHC)-copper catalyst, this method facilitated the enantioselective incorporation of a CH2 Bpin moiety at the β-position of the diesters to yield β-chiral alkyl boronates
Catalytic Enantioselective Conjugate Additions of (pin)B‐Substituted Allylcopper Compounds Generated in situ from Butadiene or Isoprene
作者:Xiben Li、Fanke Meng、Sebastian Torker、Ying Shi、Amir H. Hoveyda
DOI:10.1002/anie.201605001
日期:2016.8.16
combination of butadiene or isoprene (common feedstock), an enoate (prepared in one step) and B2(pin)2 (commercially available) are presented. These processes constitute an uncommon instance of conjugate addition of an allyl moiety and afford the desired products in up to 83 % yield and 98:2 enantiomeric ratio. Based on DFT calculations stereochemical models and rationale for the observed profiles in selectivity