Pd(II)/β-ICD-Cocatalyzed Asymmetric Route to Oxindole Scaffold via Cascade Reaction of Diazoacetamides and MBH-Carbonates
作者:Yang Yang、Chaoqun Ma、Nilesh J. Thumar、Wenhao Hu
DOI:10.1021/acs.joc.6b01703
日期:2016.9.16
report an efficient method for asymmetricsynthesis of chiral oxindoles. Allyl palladium(II) chloride dimer (APC)-catalyzed, in combination with β-isocupreidine (β-ICD)-cocatalyzed, reaction of diazoacetamide with Morita–Baylis–Hillman (MBH) carbonates proves to be a facile protocol to access multifunctional oxindoles bearing a C-3 quaternary stereo center. This tandem reaction tolerates a wide variety of
Catalytic enantioselective intramolecular cyclization of N-aryl diazoamides using a titanium–BINOLate complex
作者:Takuya Hashimoto、Kumiko Yamamoto、Keiji Maruoka
DOI:10.1039/c3cc49837a
日期:——
Catalytic enantioselective intramolecular cyclization of N-aryl diazoamides was achieved by using titanium–BINOLate as a chiral Lewis acid-assisted Brønsted acid.
Construction of 4-hydroxycoumarin derivatives with adjacent quaternary and tertiary stereocenters <i>via</i> ternary catalysis
作者:Mengchu Zhang、Tianyuan Zhang、Sifan Yu、Huang Qiu、Abdulla Yusuf、Xinfang Xu、Yu Qian、Wenhao Hu
DOI:10.1039/d3sc03452f
日期:——
4-Hydroxycoumarinderivatives represent one of the most important scaffolds in biologically active substances, pharmaceuticals and functional materials. Herein, we describe an efficient Pd/amine/Brønsted acid ternary-catalytic multicomponent reaction for the rapid construction of substituted 4-hydroxycoumarinderivatives with adjacent quaternary and tertiary stereocenters via convergent assembly of
Catalyst-Free Halogenation of α-Diazocarbonyl Compounds with <i>N</i>-Halosuccinimides: Synthesis of 3-Halooxindoles or Vinyl Halides
作者:Chaoqun Ma、Dong Xing、Wenhao Hu
DOI:10.1021/acs.orglett.6b01346
日期:2016.7.1
A novel catalyst-free halogenative cyclization of N-aryl diazoamides with N-halosuccinimides (NXS) is reported for the synthesis of 3-halooxindoles through a carbene-free mechanism. N-Aryl diazoamides reacted with NXS under mild and catalyst-free conditions to afford the corresponding 3-halooxindoles in good yields. This transformation is proposed to proceed through diazonium ion formation followed