The Divergent Cascade Reactions of Arylalkynols with Homopropargylic Amines or Electron-Deficient Olefins: Access to the Spiro-Isobenzofuran-<i>b</i>-pyrroloquinolines or Bridged-Isobenzofuran Polycycles
作者:Lun Wang、Lingyan Liu、Weixing Chang、Jing Li
DOI:10.1021/acs.joc.8b00691
日期:2018.8.3
Two divergent cascade reactions of arylalkynols with homopropargylic amines or electron-deficient olefins were developed to synthesize the spiro-isobenzofuran-b-pyrroloquinolines or bridged-isobenzofuran heterocycles in good yields, respectively. One reaction actually involved intramolecular 5-endo-dig hydroamination cyclization–protonation of homopropargylic amines to give cycloiminium ions and intramolecular
Synthesis of α-Formylated <i>N</i>-Heterocycles and Their 1,1-Diacetates from Inactivated Cyclic Amines Involving an Oxidative Ring Contraction
作者:Fang Wang、Yan He、Miaomiao Tian、Xinying Zhang、Xuesen Fan
DOI:10.1021/acs.orglett.7b04029
日期:2018.2.2
cascade reactions of N-arylpiperidines or N-arylazepanes is presented. Mechanistically, the formation of the title compounds involves an unprecedented oxidative ring contraction of inactivated cyclic amines via Cu(OAc)2/KI/O2-promoted oxidativecleavage and reformation of the C–N bond. Interestingly, when PhI(OAc)2 was used in place of KI, 1,1-diacetates of the corresponding aldehydes were directly obtained
提出了一种由N-芳基哌啶或N-芳基氮杂环庚烷的级联反应合成吡咯烷-2-甲醛或四氢吡啶-2-甲醛的新方法。从机理上讲,标题化合物的形成涉及通过Cu(OAc)2 / KI / O 2促进的氧化裂解和C–N键的重整,使灭活的环状胺发生前所未有的氧化环收缩。有趣的是,当用PhI(OAc)2代替KI时,可以高效地直接获得相应醛的1,1-二乙酸酯。据我们所知,这是区域选择性C(sp 3)–H键功能化和C(sp 3)–使用铜盐和氧使饱和环胺的N键活化。
Dual C(sp<sup>3</sup>
)−H Bond Functionalization of N-Heterocycles through Sequential Visible-Light Photocatalyzed Dehydrogenation/[2+2] Cycloaddition Reactions
through a sequential visible‐light photocatalyzed dehydrogenation/[2+2] cycloaddition procedure. As a complementary approach to the well‐established use of iminium ion and α‐amino radical intermediates, the elusive cyclic enamine intermediates were effectively generated by photoredox catalysis under mild conditions and efficiently captured by acetylene esters to form a wide array of bicyclic amino acid
Direct Arylation of α‐Amino C(sp
<sup>3</sup>
)‐H Bonds by Convergent Paired Electrolysis
作者:Yueyue Ma、Xiantong Yao、Lei Zhang、Pufan Ni、Ruihua Cheng、Jinxing Ye
DOI:10.1002/anie.201909642
日期:2019.11.11
A metal-free convergent paired electrolysis strategy to synthesize benzylic amines through direct arylation of tertiary amines and benzonitrile derivatives at room temperature has been developed. This TEMPO-mediated electrocatalytic reaction makes full use of both anodic oxidation and cathodic reduction without metals or stoichiometric oxidants, thus showing great potential and advantages for practical
Reported herein is an unprecedented photocatalytic asymmetric cross‐dehydrogenative coupling reaction between tertiary amines and simple ketones, and it proceeds by synergistic multiple catalysis with substoichiometric amounts of a hydrogen acceptor. This process is enabled by a simple chiral primary amine catalyst through the coupling of a catalytic enamine intermediate and an iminium cation intermediate