Synthesis of 1,6-Dihydropyridine-3-carbonitrile Derivatives <i>via</i> Lewis Acid-Catalyzed Annulation of Propargylic Alcohols with (<i>E</i>)-3-Amino-3-phenylacrylonitriles
作者:Li-Juan Du、Yuecheng Zhang、Hong-Yu Zhang、Guohui Yin、Xiao-Yan Wang、Jiquan Zhao、Ya-Ping Han
DOI:10.1021/acs.joc.0c01171
日期:2020.8.7
acid-catalyzed, highly efficient, practical, and atom-economical protocol for the synthesis of functionalized 1,2-dihydropyridine-3-carbonitrile derivatives in the presence of Bi(OTf)3 (10 mol %) in tetrahydrofuran (2.0 mL) at 80 °C for 8 h in air is described, starting from readily accessed propargylic alcohols and (E)-3-amino-3-phenylacrylonitriles. This cycloaddition protocol, which is scalable and
A new method for the efficient synthesis of hexahydro-1H-fluorene and octahydrobenzo[a]azulene derivatives through a ring-expansion strategy is reported. With an appropriate combination of thulium(III) trifluoromethanesulfonate and 13X molecular sieves, a range of unsaturated polycycliccompounds were obtained in good yields. Mechanism studies reveal that the reaction is more likely to undergo Meyer–Schuster
tricyclic compounds possessing functionalizedpyrano[3,2‐c]chromen‐5(2H)‐one fragments has been developed using propargylic alcohols and 4‐hydroxy‐2H‐chromen‐2‐ones as the substrates. The protocol provides a one‐step, environmentally benign method of accessing a broad range of pyrano[3,2‐c]chromen‐5(2H)‐one derivatives in excellent yields undermildconditions and with good functional‐group tolerance. The method
A novel copper(II) trifluoromethanesulfonate‐catalyzed intermolecular cascade annulation strategy for the construction of a great variety of pentacyclic compounds possessing valuable carbazole fragments was developed employing propargylic alcohols and (Z)‐2‐styryl‐1H‐indoles as the initial substrates. This protocol, which entails a sequential Meyer‐Schuster rearrangement/isomerization/‐cyclization
method with high efficiency for the synthesis of α,β-unsaturated amides from the easily prepared propargyl alcohols and TMSN3 using TMSCl as an acid promoter is developed. A wide variety of α,β-unsaturated amides were produced in moderate to excellent yields. Mechanistic studies indicate that this transformation involves TMSCl-mediated allenylazide intermediate formation, C–C bond cleavage, and C–N