A direct method for the synthesis of 1,2,5-triaryl-1H-imidazoles was achieved easily from cyclization of aryl acetaldehydes with amidines catalyzed by I2. Various substitued groups can be employed, and this reaction proceeds smoothly in moderate to good yields.
Iron(III)-catalyzed synthesis of multi-substituted imidazoles via [3+2] cycloaddition reaction of nitroolefins and N-aryl benzamidines
作者:Xiang Liu、Dong Wang、Baohua Chen
DOI:10.1016/j.tet.2013.08.077
日期:2013.11
A novel and efficient iron(III)-catalyzedsynthesis of multi-substituted imidazoles via [3+2] cycloaddition of nitroolefins and N-aryl benzamidines under the air atmosphere had been developed. This methodology is convenient, atom-economical, general, and eco-friendly in good yields and prefect regioselectivities.
A simple route for the synthesis of imidazole derivatives via copper-catalyzed [3 + 2] cycloaddition reaction is described. This strategy has achieved high regioselectivity and used oxygen as an oxidant without the addition of expensive catalysts to provide moderate to good yields.
Iron(III)/Iodine-Catalyzed C(<i>sp</i><sup>2</sup>)H Activation of α,β-Unsaturated Aldehydes/Ketones with Amidines: Synthesis of 1,2,4,5-Tetrasubstituted Imidazoles
An efficient methodology to access a library of 1,2,4,5-tetrasubstitutedimidazoles from a broad range of amidines and α,β-unsaturatedaldehydes/ketones via a C(sp2)H amination has been developed. This method represents a new and simple way to prepare highly substituted imidazoles from easily available starting materials, inexpensive catalysts, and with good functional group tolerance in good to excellent
Selective Synthesis of Aminoisoquinolines via Rh(III)-Catalyzed C–H/N–H Bond Functionalization of <i>N</i>-Aryl Amidines with Cyclic 2-Diazo-1,3-diketones
C–H/N–H bond functionalization of N-aryl amidines with cyclic 2-diazo-1,3-diketones for the synthesis of 1-aminoisoquinolines has been accomplished by employing [Cp*RhCl2]2/CsOPiv as the catalyst system. This methodology proceeds by a cascade C–H activation/intramolecular cyclization under mild reaction conditions, features a broad substrate scope, and involves the formation of two new σ bonds (C–C and