1-Imidoyl-1,2,3-benzotriazoles—Novel Reagents for the Synthesis of 1-Aryl-5-trifluoromethylimidazoles
摘要:
1-Imidoylbenzotriazoles [N-aryl-1-(1H-benzotriazol-1-yl)-2,2,2-trifluoroethan-1-imines] reacted with tosylmethyl isocyanide according to van Leusen's procedure to give difficultly accessible 1-aryl-4-(4-methylbenzenesulfonyl)-5-(trifluoromethyl)-1H-imidazoles in good yields (81-94%). The initial imidoylbenzotriazoles were conveniently synthesized by reaction of sodium benzotriazolide with the corresponding imidoyl chlorides in THF. The reactions were carried out with a wide series of imidoylbenzotriazoles containing various electron-donating and electron-withdrawing substituents in the N-aryl fragment.
A metal‐free approach for the synthesis of 5‐trifluoromethyl‐1,2,4‐triazoles from trifluoroacetimidoyl chlorides and hydrazones has been achieved under aerobic oxidative conditions. The reaction proceeds through a cascade base‐promoted intermolecular C−N bond formation and iodine‐mediated intramolecular C−N bond oxidative coupling sequence. The protocol features broad substrate scope and can be scaled
Cu-catalyzed tandem reactions of fluorinated alkynes with sulfonyl azides en route to 2-trifluoromethylquinolines
作者:Yajun Li、Lisi Zhang、Li Zhang、Yongming Wu、Yuefa Gong
DOI:10.1039/c3ob41658e
日期:——
A novel method for the synthesis of 2-trifluoromethylquinolines via Cu-catalyzed tandem reactions was reported. A strong electronic effect was observed, but the steric effect was negligible.
e annulation reaction for the efficient construction of 2-(trifluoromethyl)quinazolin-4(3H)-ones has been developed. This transformation employs readily available isatins and trifluoroacetimidoyl chlorides as the starting materials, providing a facile and practical route to diverse biologically relevant quinazolin-4(3H)-one derivatives. A plausible reaction pathway has been proposed based on the mechanistic
metal-free approach for the synthesis of 5-trifluoromethyl-1,2,4-triazoles via I2-mediated [4+1] annulation of readily available trifluoroacetimidohydrazides and methyl ketones has been achieved. The transformation involves iodination/Kornblum oxidation, intermolecular dehydration condensation and an iodine-mediated intramolecular cyclization/aromatization sequence. The developed protocol can be easily scaled
已经实现了一种通过 I 2介导的 [4+1] 环化容易获得的三氟乙酰氨基酰肼和甲基酮来合成 5-三氟甲基-1,2,4-三唑的无金属方法。该转化包括碘化/Kornblum 氧化、分子间脱水缩合和碘介导的分子内环化/芳香化序列。开发的协议可以很容易地扩展到 3 mmol 规模而不会明显降低效率,并且可以通过连续的一锅方式实施。