Selectfluor-mediated regioselective nucleophilic functionalization of N-heterocycles under metal- and base-free conditions
作者:Long-Yong Xie、Jie Qu、Sha Peng、Kai-Jian Liu、Zheng Wang、Man-Hua Ding、Yi Wang、Zhong Cao、Wei-Min He
DOI:10.1039/c7gc03106h
日期:——
A facile, practical and environmentally attractive protocol for the direct diversification of N-heterocycles under ambient, metal- and base-free conditions was developed.
在常温、无金属和无碱条件下,开发了一种简便、实用且环境友好的直接多样化N-杂环的协议。
Base free regioselective synthesis of α-triazolylazine derivatives
A regioselective α-heteroarylation followed by deoxygenation towards the synthesis of variety of azine triazole from simple azine N-oxides derivatives and N-tosyl-1,2,3-triazoles has been described. The reaction is metal free and basefree with shorter reaction time, high yields and a broad substrate scope.
Synthesis of 6-Substituted Pyrido[2,3-<i>b</i>]indoles by Electrophilic Substitution
作者:Peter Goekjian、Cédric Schneider、David Gueyrard、Florence Popowycz、Benoît Joseph
DOI:10.1055/s-2007-985566
日期:——
Regioselective electrophilic aromatic substitutions, acylation, bromination, and formylation, of unprotected pyrido[2,3- B]indole (α-carbolines) at the C-6 position are described. Alter-native conditions for the nitration were investigated, which led to the -unexpected appearance of the minor C-8 isomer.
A Simple, Versatile Synthetic Route to<i>N</i>-1-Aryl-, -Heteroaryl-, - Acylmethyl-, -Carboxymethyl-and -Alkyl-benzotriazoles via Regiospecific or Highly Regioselective Substitutions of Benzotriazole
作者:Alan R. Katritzky、Jing Wu
DOI:10.1055/s-1994-25530
日期:——
In the absence of any added base in refluxing benzene or toluene, benzotriazole replaces the halogen atom of an α-halogenated ketone or a carboxylic ester to give the corresponding N-1-substituted benzotriazole as the only isomer. 2-Bromopyridine and 1-chloro-2,4-dinitrobenzene reacted similarly with benzotriazole to afford the corresponding N-1-substituted benzotriazole derivatives in quantitative yields. Alkyl halides reacted regioselectively to afford the N-1-alkylbenzotriazoles in ratios of more than 10 to 1 over the N-2 isomers. An α-(benzotriazol-1-yl)carboxylic ester was hydrolyzed into the corresponding carboxylic acid, which upon heating under-went smooth decarboxylation into the corresponding 1-alkylbenzotriazole.
A comparison of some pyrolysis reactions of benzotriazoles, benzisoxazolones and benzisothiazolones
作者:Wit K. Janowski、Rolf H. Prager、Jason A. Smith
DOI:10.1039/b004825i
日期:——
The products of flash vacuum pyrolysis of N-acetyl, N-methyl, N-benzyl and N-heteroaryl-substituted benzotriazole, 2,1-benzoxazol-3-one and 2,1-benzothiazol-3-one have been compared. The pyrolysis of benzotriazoles and benzisoxazolones appears to involve an iminocarbene intermediate, although the N-benzyl analogues react by radical pathways. Benzisothiazolones appear to form iminoketene intermediates.