Catalytic Multicomponent Reactions for the Synthesis of <i>N</i>-Aryl Trisubstituted Pyrroles
作者:Chris V. Galliford、Karl A. Scheidt
DOI:10.1021/jo0624086
日期:2007.3.1
Dirhodium(II) salts efficiently catalyze the three-component assembly reaction of an imine, diazoacetonitrile (DAN), and an activated alkynyl coupling partner to form substituted 1,2-diarylpyrroles in moderate to good yields. The transition-metal-catalyzed decomposition of the diazocompound in the presence of the imine presumably generates a transient azomethine ylide that undergoes cycloaddition
2-Benzotriazolylaziridines and Their Reactions with Diethyl Acetylenedicarboxylate
作者:Alan R. Katritzky、Jiangchao Yao、Weiliang Bao、Ming Qi、Peter J. Steel
DOI:10.1021/jo980082y
日期:1999.1.1
1-Alkyl-2-benzotriazolylaziridines (3a,b and 8a-g) are synthesized by two routes utilizing a novel benzotriazolyl-substituted carbenoid or 1,2-dibromoethylbenzotriazole. Lithiation of 3b and 8e at the position a to benzotriazole and subsequent trapping with alkyl halides leads to the 1,2-dialkyl-2-benzotriazolylaziridine analogues 12 and 20. Compounds 3a and 3b react with acetylenedicarboxylic ester by C-C bond breaking to give pyrrole-3,4-dicarboxylic esters (14a,b). By contrast, compounds 8a-d and 20 react with acetylenedicarboxylic ester by C-N bond breaking and form pyrrole-2,3-dicarboxylic esters 18a-d and 21. Structures of each type of pyrroledicarboxylic ester are established by X-ray analysis.