The first example of diastereo- and enantioselective aza-MBH-type reaction was accomplished by the asymmetric synthesis of β-nitro-γ-enamines via a (1R,2R)-diaminocyclohexane thiourea derivative mediated tandem Michael addition and aza-Henry reaction in good yields (up to 95%) and high enantioselectivities (up to 91% ee) and diastereoselectivities (up to 1:99 dr).
Nitroolefins as a Nucleophilic Component for Highly Stereoselective Aza Henry Reaction under the Catalysis of Chiral Ammonium Betaines
作者:Daisuke Uraguchi、Keigo Oyaizu、Takashi Ooi
DOI:10.1002/chem.201201259
日期:2012.7.2
was successfully generated from β,β‐disubstituted nitroolefins for achieving a highly regio‐, diastereo‐, and enantioselective aza Henry reaction under the influence of chiralammoniumbetaine of type 1 as an organic‐base catalyst. The present approach greatly expands the synthetic utility of nitroolefins in the development of carbon–carbon bond‐forming reactions (see scheme).