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.
Bifunctional Organocatalytic Strategy for Inverse-Electron-Demand Diels-Alder Reactions: Highly Efficient In Situ Substrate Generation and Activation to Construct Azaspirocyclic Skeletons
作者:Xianxing Jiang、Xiaomei Shi、Shoulei Wang、Tao Sun、Yiming Cao、Rui Wang
DOI:10.1002/anie.201107716
日期:2012.2.27
highly enantioselective organocatalytic version of the title reactionusing an in situ substrate generation/activation catalytic mode is described (see scheme). The reaction provides an efficient enantioselective construction of functionalized azaspirocyclic skeletons. The in situgeneration of the enolate provides a new way in which to use this important nucleophile in organic synthesis.
Dearomatization/Deiodination of <i>o</i>-Iodophenolic Compounds with α,β-Unsaturated Imines for Accessing Benzofuran Derivatives
作者:Bigui Zhou、Zhiwei Yuan、Jingxun Yu、Xinjun Luan
DOI:10.1021/acs.orglett.1c04065
日期:2022.1.28
Three-Component Functionalized Dihydropyridine Synthesis via a Formal Inverse Electron-Demand Hetero-Diels–Alder Reaction
作者:Xiaonan Yan、Fei Ling、Yuchen Zhang、Cheng Ma
DOI:10.1021/acs.orglett.5b01622
日期:2015.7.17
A mild three-component synthetic approach to versatile 2-amino-1,4-dihydropyridines from terminal alkynes, sulfonyl azides, and N-sulfonyl-1-aza-1,3-butadienes was successfully developed and relied on the in situ generation of metalated ynamide intermediates Ib to achieve a formal inverse electron-demand hetero-Diels-Alder reaction. Experimental results suggest that alkali Metal cations (Li+ and Cs+ ions) might play a critical role to achieve the cycloaddition process.