Catalytic Asymmetric β,γ Activation of α,β-Unsaturated γ-Butyrolactams: Direct Approach to β,γ-Functionalized Dihydropyranopyrrolidin-2-ones
作者:Xianxing Jiang、Luping Liu、Panpan Zhang、Yuan Zhong、Rui Wang
DOI:10.1002/anie.201302622
日期:2013.10.18
Skeleton in the closet: The title reaction enables the development of the first catalyticβ,γ‐selective Diels–Alder [4+2] annulation of α,β‐unsaturated γ‐butyrolactams (see scheme; Boc=tert‐butoxycarbonyl, Ts=4‐toluenesulfonyl). This process provides a direct method for the enantioselective construction of bi‐ or tricyclic dihydropyranopyrrolidin‐2‐one skeletons in only one step.
The catalytic asymmetric synthesis of CF<sub>3</sub>-containing spiro-oxindole–pyrrolidine–pyrazolone compounds through squaramide-catalyzed 1,3-dipolar cycloaddition
important compounds were synthesized through the organocatalytic 1,3-dipolar cycloadditionreaction. In the presence of a cinchonine-derived squaramide catalyst, the cycloaddition of N-2,2,2-trifluoroethylisatin ketimines with α,β-unsaturated pyrazolones gave a spiro-pyrrolidine-linked oxindole and pyrazolone compound bearing four consecutive stereocenters and two vicinal spiroquaternary chiral centers