A variety of ketonitrones were synthesized in moderate to excellent yields with high chemo-, regio-, and stereoselectivity by using carbonyl-directed addition of N-alkylhydroxylamines to unactivated alkynes under mild conditions. The product diverisity could be controlled by the use of different bases, and EtN(n-Pr)2 could promote the formation of ketonitrones while using EtONa as base led to indanone-derived
Palladium-Catalyzed Cascade Decarboxylative Amination/6-<i>endo-dig</i> Benzannulation of <i>o</i>-Alkynylarylketones with <i>N</i>-Hydroxyamides To Access Diverse 1-Naphthylamine Derivatives
An efficient and practical one-pot strategy to produce highly substituted 1-naphthylamines via sequential palladium-catalyzed decarboxylative amination/intramolecular 6-endo-dig benzannulation reactions has been described. In this reaction, a broad range of electron-rich, electron-neutral, and electron-deficient o-alkynylarylketones react well with N-hydroxyl aryl/alkylamides to give a diversity of
Synthesis of Chiral Tetrasubstituted Alkenes by an Asymmetric Cascade Reaction Catalyzed Cooperatively by Cationic Rhodium(I) and Silver(I) Complexes
作者:Daiki Hojo、Keiichi Noguchi、Ken Tanaka
DOI:10.1002/anie.200904024
日期:2009.10.12
have been prepared with high enantioselectivity by the title transformation. This reaction was successfully applied to the enantio‐ and diastereoselective synthesis of tetrasubstituted helical alkenes possessing both central and helical chirality (see scheme).
Highly Chemo-, Regio- and <i>E/Z</i>-Selective Intermolecular Heck-Type Dearomative [2 + 2 + 1] Spiroannulation of Alkyl Bromoarenes with Internal Alkynes
作者:Xingrong Liao、Deping Wang、Yueyuan Huang、Yudong Yang、Jingsong You
DOI:10.1021/acs.orglett.9b00099
日期:2019.2.15
bromoarenes with internal alkynes. Challenges in this spiroannulation include the chemoselectivity among [2 + 2 + 1], [2 + 2 + 2], and [3 + 2] annulations and the E/Z-selectivity associated with the generated exocyclic doublebond. In the presence of Pd(OAc)2 and a phosphine ligand, a variety of highly functionalized spirocyclopentadienes with an exocyclic carbon–carbon doublebond are provided in good to excellent
Radical Cascade Bicyclization/Aromatization of 1,7‐Enynes with 1,3‐Dicarbonyl Compounds towards 2,3‐Dihydro‐1
<i>H</i>
‐cyclopenta[
<i>a</i>
]naphthalenes
An Ag-catalyzed radical cascade bicyclization/aromatization of C-linked 1,7-enynes with 1,3-dicarbonyls has been achieved, providing a step- and atom-economy approach for the construction of 2,3-dihydro-1H-cyclopenta[a]naphthalenes, an important structural scaffold existed in biologically active compounds. From this transformation, structurally diverse 2,3-dihydro-1H-cyclopenta[a]naphthalenes were
已经实现了银催化自由基级联双环化/芳构化的C-连接的 1,7-烯炔与 1,3-二羰基,为构建 2,3-二氢-1 H-提供了一步和原子经济的方法-环戊二烯[ a ]萘,一种重要的结构支架,存在于生物活性化合物中。通过这种转化,以中等至良好的产率和高区域选择性获得了结构多样的 2,3-二氢-1 H-环戊二烯 [ a ] 萘。此外,还举例说明了进一步的产品衍生化。