Tri- and tetrasubstituted N–H pyrroles were prepared by the simple treatment of vinyl azides with 1,3-dicarbonylcompounds in toluene at 100 °C via 2H-azirine intermediates generated in situ. When the reactions of vinyl azides and 1,3-dicarbonylcompounds were performed in DMF in the presence of a catalytic amount of K2CO3, 1-vinyl-1,2,3-triazoles were obtained via 1,3-dipolar cycloaddition. These
三-和四取代Ñ经由2在100℃下在甲苯中的简单处理乙烯基叠氮化物与1,3-二羰基化合物制备-H吡咯ħ原位产生-azirine中间体。当在催化量的K 2 CO 3存在下,叠氮化乙烯和1,3-二羰基化合物的反应在DMF中进行时,通过1,3-偶极环加成反应获得1-乙烯基-1,2,3-三唑。这些方法利用了叠氮化乙烯基化学反应的正交模式,这可以通过稍微改变反应条件来实现。
Synthesis of Substituted Indoles from 2-Azidoacrylates and <i>ortho</i>-Silyl Aryltriflates
作者:Deng Hong、Zhengbo Chen、Xufeng Lin、Yanguang Wang
DOI:10.1021/ol101934v
日期:2010.10.15
2-Azidoacrylates react with benzynes in the presence of PPh3 and CsF to afford substituted indoles in good yields. The reaction involves the formation of iminophosphorane and benzyne and a subsequent double cyclization/hydrolysis/air-oxidation cascade. This methodology was utilized to synthesize 10H-indolo[1,2-a]indol-10-ones.
An efficient method for the synthesis of polyfunctional imidazoles from vinyl azides and amidine has been developed. Starting from vinyl azide and amidine, this transformation proceeds without any additives and the obtained imidazoles can be decorated with ester functional group that is a promising site for further modification.
Catalyst-Free Preparation of 1,2,4,5-Tetrasubstituted Imidazoles from a Novel Unexpected Domino Reaction of 2-Azido Acrylates and Nitrones
作者:Bao Hu、Zhao Wang、Ning Ai、Jie Zheng、Xing-Hai Liu、Shang Shan、Zhongwen Wang
DOI:10.1021/ol202650z
日期:2011.12.16
A highly efficient and convenient method for the synthesis of 1,2,4,5-tetrasubstitutedimidazoles from readily accessible 2-azidoacrylates and nitrones has been developed. This reaction proceeded under mild conditions without the assistance of any metal, acid, or base.
An efficient annulation of vinylazides with activated imines has been developed for the synthesis of poly-functionalized imidazole derivatives. This reaction includes thermal decomposition of vinylazides to 2H-azirines, nucleophilic attack of 2H-azirines with activated imines and subsequent cyclization to desired imidazoles.