Trifluoromethylation of Allylsilanes under Copper Catalysis
作者:Satoshi Mizuta、Oscar Galicia-López、Keary M. Engle、Stefan Verhoog、Katherine Wheelhouse、Gerasimos Rassias、Véronique Gouverneur
DOI:10.1002/chem.201201707
日期:2012.7.9
Branched allylic CF3 products are accessible by copper‐catalyzed trifluoromethylation of allylsilanes with the Togni reagent I. The silyl group is critical to control the outcome of this reaction because in its absence, a product of addition between the alkene and the Togni reagent is formed preferentially. The reaction is inhibited with 2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO) and is likely to
Copper-Catalyzed Decarboxylative Trifluoromethylation of Allylic Bromodifluoroacetates
作者:Brett R. Ambler、Ryan A. Altman
DOI:10.1021/ol402780k
日期:2013.11
this transformation typically requires four-step processes, specialty chemicals, and/or stoichiometric metals to access the trifluoromethyl-containing product. A two-step copper-catalyzed decarboxylative protocol for converting allylic alcohols to trifluoromethanes is reported. Preliminary mechanistic studies distinguish this reaction from previously reported Cu-mediated reactions.
Trifluoromethylation of aromatic alkenes by visible-light-driven photoredox catalysis: Direct conversion of alkenes to 3-trifluoromethyl-1-propenyl and 1,3-bis(trifluoromethyl)-1-propenyl derivatives
irradiation has been developed. A Ru photocatalyst, [Ru(bpy)3](PF6)2 (bpy = 2,2′-bipyridine), is useful for the present trifluoromethylation and preferable formation of 3-trifluoromethyl-1-propenyl derivatives is observed. Use of an excess amount of Umemoto's reagent readily induces double trifluoromethylation of electron-rich alkenes, resulting in 1,3-bis(trifluoromethyl)-1-propenyl skeleton.
An efficient palladium‐catalyzed Heck‐type reaction of fluoroalkyl halides, including perfluoroalkyl bromides, trifluoromethyl iodides, and difluoroalkyl bromides, has been developed. The reaction proceeds under mild reaction conditions with high efficiency and broad substrate scope, and provides a general and straightforward access to fluoroalkylated alkenes which are of interest in life and material
We previously found that treatment of (Z)-trifluoromethylated-2-aryl allylicalcohols with organolithium provided the SN2′-type product through CO bond cleavage. Interestingly, no additive was required to enhance the nucleophilicity of the organolithium, and the free hydroxyl group served as a leaving group. The mechanistic studies of the unique transformation indicated that chelation of alkoxide and
我们先前发现,用有机锂处理(Z)-三氟甲基化-2-芳基烯丙基醇可通过C O键断裂提供S N 2'型产物。有趣的是,不需要添加剂来增强有机锂的亲核性,并且游离羟基用作离去基团。独特转化的机理研究表明,三氟甲基的醇盐和氟与锂离子的螯合在控制反应性和选择性方面起着至关重要的作用。此外,理论研究也支持这种解释。