Phosphazene Superbase-Mediated Regio- and Stereoselective Iodoaminocyclization of 2-(1-Alkynyl)benzamides for the Synthesis of Isoindolin-1-ones
作者:Saurabh Mehta、Dhirendra Brahmchari
DOI:10.1021/acs.joc.9b00452
日期:2019.5.3
exclusive formation of products with Z-geometry (across the exo C═C bond) has been confirmed through X-raycrystallography. The methodology also provides an easy access to aristolactams, an important class of natural products. This has been successfully demonstrated by synthesizing two aristolactam derivatives (including Cepharanone B).
A Highly Regio and Stereoselective Synthesis of (<i>Z</i>)-3-Aryl(alkyl)idene Isoindolin-1-ones via Palladium Catalyzed Annulation of Terminal Alkynes
作者:M. Khan、Nitya Kundu
DOI:10.1055/s-1997-1049
日期:——
o-Iodobenzamide or its N-substituted derivatives 4-10 and terminal alkynes 11-17 reacted in DMF in the presence of bis(triphenylphosphine)palladium(II)chloride, cuprous iodide and triethylamine leading to (Z)-3-arylidene isoindolin-1-ones (22, 24, 27 and 28) or o-alkynyl N-substituted benzamides (I). The latter could be cyclised with sodium in ethanol in a completely regio and stereoselective manner to (Z)-3-aryl(alkyl)idene isoindolin-1-ones 18-35.
Ruthenium-Catalyzed Cycloisomerization of Aromatic Homo- and Bis-Homopropargylic Amines/Amides: Formation of Indoles, Dihydroisoquinolines and Dihydroquinolines
作者:Alejandro Varela-Fernández、Jesús A. Varela、Carlos Saá
DOI:10.1002/adsc.201100095
日期:2011.8
Ruthenium-catalyzed cycloisomerizations of aromatic homo- and bis-homopropargylic amines/amides efficiently afford indoles, dihydroisoquinolines and dihydroquinolines. These processes were regioselective (5- and 6-endo cyclizations) on using key Ru vinylidene intermediates. The presence of an amine/ammonium base-acid pair increased the rate of cyclization and facilitated the catalytic turnover.
CyclocarbonylativeSonogashirareactions of ortho-ethynylbenzamides have been investigated. The process is carried out under CO pressure, in the presence of a very small amount of PdCl2(PPh3)2 (0.4 mol %) as a catalytic precursor and without the need for a Cu salt as the co-catalyst. 2-Ethynylbenzamide reacted successfully with iodoarenes bearing electron-withdrawing and electron-donating groups, giving
Synthesis of 1-Aminoisoquinolines by Gold(III)-Mediated Domino Reactions from 2-Alkynylbenzamides and Ammonium Acetate
作者:Yuhua Long、Zhigang She、Xiaochen Liu、Yu Chen
DOI:10.1021/jo302794z
日期:2013.3.15
1-aminoisoquinoline derivatives by gold(III)-mediated domino reactions is described. This synthetic protocol starts from readily available 2-alkynylbenzamides and ammonium acetate and takes place under mild reaction conditions compatible with a variety of functional groups. A plausible mechanism for the dominoprocess is proposed, supported by the reaction of a possible intermediate, N-(3-phenyl-1H-isochrom