A novel and efficient iron-catalyzed cycloaddition reaction using readily available 2,3-diaryl-2H-azirines and primary amides is reported. A wide range of trisubstituted oxazoles could be achieved in good yields with good functional group compatibility. In this transformation, two C–N bonds were cleaed and new C–N and C–O bonds were formed.
General Synthesis of Tri-Carbo-Substituted <i>N</i><sup>2</sup>-Aryl-1,2,3-triazoles <i>via</i> Cu-Catalyzed Annulation of Azirines with Aryldiazonium Salts
作者:Fang-Fang Feng、Jun-Kuan Li、Xuan-Yu Liu、Fa-Guang Zhang、Chi Wai Cheung、Jun-An Ma
DOI:10.1021/acs.joc.0c01433
日期:2020.8.21
The general synthesis of fully substituted N2-aryl-1,2,3-triazoles is hitherto challenging compared with that of the N1-aryl counterparts. Herein, we describe a Cu-catalyzed annulation reaction of azirines and aryldiazonium salts. This regiospecific method allows access to a broad spectrum of tri-carbo N2-aryl-1,2,3-triazoles substituted with diverse aryl and alkyl moieties. Its utility is highlighted
An efficient nickel-catalyzed formal [3 + 2]-cycloaddition of 2H-azirines with 1,3-dicarbonylcompounds for the synthesis of tetrasubstituted pyrroles has been developed. This transformation involves cleavage of the CN double bond and the construction of new CC and CN bonds. The reaction employs readily available starting materials, tolerates a wide range of functional groups, and affords tetrasubstituted
Here we report a novel interrupted azirine–alkyne ring-expansionreaction with molecular oxygen for the direct synthesis of highly functionalized pyrrolones enabled by copper catalysis. Mechanistic investigations indicate that the present three-component reaction proceeds via two copper-catalyzed sequential reactions, an azirine-ring-opening alkynylation and an amine-directed radical oxygenation, leading
Zinc-Enabled Annulation of Trifluorodiazoethane with 2<i>H</i>-Azirines to Construct Trifluoromethyl Pyrazolines, Pyrazoles, and Pyridazines
作者:Yue-Ji Chen、Fa-Guang Zhang、Jun-An Ma
DOI:10.1021/acs.orglett.1c02139
日期:2021.8.6
involves two [3 + 2] cycloaddition steps and one dinitrogen extrusion process in one pot, thus giving a broad array of 3-trifluoromethyl pyrazolines in good yields with excellent diastereoselectivities. Further transformations provide facile access to 3-trifluoromethyl pyrazoles and 3,5-ditrifluoromethyl pyridazines with good efficiency.