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。
Annulation of CF<sub>3</sub>–Imidoyl Sulfoxonium Ylides with 1,3-Dicarbonyl Compounds: Access to 1,2,3-Trisubstituted 5-Trifluoromethylpyrroles
A lithium-bromide-promoted nucleophilicsubstitution/annulation cascade reaction between CF3-imidoyl sulfoxonium ylides and 1,3-dicarbonyl compounds has been established, and the corresponding 1,2,3-trisubstituted 5-trifluoromethylpyrroles have been obtained in 27–78% yield. This reaction features a broad substrate scope and generates dimethylsulfoxide and H2O as byproducts.
已经建立了溴化锂促进的 CF 3 -亚氨酰基锍叶立德与 1,3-二羰基化合物之间的亲核取代/环化级联反应,并在 27-78 年获得了相应的 1,2,3-三取代 5-三氟甲基吡咯% 屈服。该反应具有广泛的底物范围,并生成二甲基亚砜和 H 2 O 作为副产物。