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
Ring expansion of 11H-benzo[b]fluorene-11-methanols and related compounds leading to 17,18-diphenyldibenzo[a,o]pentaphene and related polycyclic aromatic hydrocarbons with extended conjugation and novel architectures
作者:Yonghong Yang、Weixiang Dai、Yanzhong Zhang、Jeffrey L. Petersen、Kung K. Wang
DOI:10.1016/j.tet.2006.02.066
日期:2006.5
88% yield. Similarly, 17,18-diphenyldibenzo[a,o]pentaphene possessing a helical twist and bearing two phenyl substituents at the most sterically congested C17 and C18 positions and other related compounds were likewise synthesized. Subsequent intramolecular arylation reactions involving the phenyl substituents produced polycyclic aromatichydrocarbons with novel architectures.
7-(1,1-二甲基乙基)-13-苯基-8 H-茚并[2,1 - b ]菲与低聚甲醛缩合产生相应的9-芴基甲醇衍生物,该衍生物经P 2 O 5处理可促进Wagner反应–扩环的Meerwein重排提供了88%收率的14-苯基二苯并[ a,j ]蒽。同样,17,18-二苯基二苯并[ a,o具有最螺旋的C17和C18位置具有螺旋形扭曲并带有两个苯基取代基的]戊苯和其他相关化合物也被合成。随后的涉及苯基取代基的分子内芳基化反应产生具有新颖结构的多环芳烃。