Rhodium(III)-Catalyzed<i>ortho</i>Alkenylation of<i>N</i>-Phenoxyacetamides with<i>N</i>-Tosylhydrazones or Diazoesters through CH Activation
作者:Fangdong Hu、Ying Xia、Fei Ye、Zhenxing Liu、Chen Ma、Yan Zhang、Jianbo Wang
DOI:10.1002/anie.201309650
日期:2014.1.27
A coupling reaction of N‐phenoxyacetamides with N‐tosylhydrazones or diazoestersthrough RhIII‐catalyzed CHactivation is reported. In this reaction, ortho‐alkenyl phenols were obtained in good yields and with excellent regio‐ and stereoselectivity. Rh–carbene migratory insertion is proposed as the key step in the reaction mechanism.
Synthesis of Spirocyclic Enones by Rhodium-Catalyzed Dearomatizing Oxidative Annulation of 2-Alkenylphenols with Alkynes and Enynes
作者:Szymon Kujawa、Daniel Best、David J. Burns、Hon Wai Lam
DOI:10.1002/chem.201403454
日期:2014.7.7
The dearomatizing oxidative annulation of 2‐alkenylphenols with alkynes and enynes proceeds with high yields and regioselectivities under RhIII catalysis. These reactions are successful using Cu(OAc)2 or air as the stoichiometric oxidant, and provide spirocyclic enones, the basic ring system of which appears in several natural products. Application of this process to the preparation of a highly functionalized
Visible-Light-Induced Difluoroalkylation of 1-(Allyloxy)-2-(1-arylvinyl)benzenes and 1-(1-Arylvinyl)-2-(vinyloxy)benzenes: Synthesis of Bis-Difluoroalkylated Benzoxepines and 2<i>H</i>-Chromenes
A novel visible-light-mediated difluoroalkylation of 1-(allyloxy)-2-(1-arylvinyl)benzenes and 1-(1-arylvinyl)-2-(vinyloxy)benzenes for the synthesis of bis-difluoroalkylated benzoxepines and 2H-chromenes is developed. This method features mild reaction conditions, good regioselectivity, a wide substrate scope, good functional-group compatibility, and late-stage modification. Preliminary mechanistic
1-(烯丙氧基)-2-(1-芳基乙烯基)苯和1-(1-芳基乙烯基)-2-(乙烯基氧基)苯的新型可见光介导二氟烷基化合成双-二氟烷基苯并氧杂环庚烷和2 H-开发了色烯。该方法具有反应条件温和、区域选择性好、底物范围广、官能团相容性好、后期修饰等特点。初步机理研究表明,CF 2 CO 2 Et 自由基的生成更容易与芳基的双键发生反应。
Substituent-Controlled Copper-Catalyzed Trifluoromethylation of 1,7-Dienes: Synthesis of Mono- and Bis-trifluoromethylated Benzoxepines
A copper-catalyzed trifluoromethylation of benzene-linked 1,7-dienes with 1-trifluoromethyl-1,2-benziodoxole via a radical cascade cyclization process for the synthesis of mono- and bis-trifluoromethylated benzoxepines is developed. The selectivity depends on substituents on the double bond of the allyl group in 1,7-dienes. The large-scale operation and late-stage functionalization of bioactive molecules