Regioselective Gold-Catalyzed Hydration of CF3- and SF5-alkynes
摘要:
The regioselective gold-catalyzed hydration of CF3- and SF5-alkynes is described. The corresponding trifluoromethylated and pentasulfanylated ketones are obtained in up to 91% yield as single regioisomers showcasing the use of CF3 and SF5 as highly efficient directing groups in this reaction. Notably, this transformation represents the first use of CF3- and SF5-alkynes in gold catalysis.
Radical C(sp<sup>2</sup>)–H Trifluoromethylation of Aldehydes in Aqueous Solution
作者:Pei Zhang、Haigen Shen、Lin Zhu、Weiguo Cao、Chaozhong Li
DOI:10.1021/acs.orglett.8b03012
日期:2018.11.16
The copper-mediated C(sp2)–H trifluoromethylation of aldehydes is described. The reaction of aldehydes with (bpy)Cu(CF3)3, Et3SiH, and K2S2O8 in aqueous acetone at room temperature provides the corresponding trifluoromethyl ketones in satisfactory yields. The protocol is applicable to both aliphatic and aromatic aldehydes and exhibits a broad substrate scope and wide functional group compatibility
描述了铜介导的醛的C(sp 2)–H三氟甲基化。在室温下,醛与(bpy)Cu(CF 3)3,Et 3 SiH和K 2 S 2 O 8在丙酮水溶液中的反应以令人满意的产率提供了相应的三氟甲基酮。该协议适用于脂族和芳族醛,并具有广泛的底物范围和广泛的官能团相容性。提出了一种涉及Cu(II)介导的酰基三氟甲基化的机理。
Direct conversion of primary and secondary carboxylic acids to trifluoromethyl ketones
作者:Jonathan T. Reeves、Fabrice Gallou、Jinhua J. Song、Zhulin Tan、Heewon Lee、Nathan K. Yee、Chris H. Senanayake
DOI:10.1016/j.tetlet.2006.11.068
日期:2007.1
Primary and secondary carboxylic acids were converted in one step to the corresponding trifluoromethyl ketones by treatment with trifluoroacetic anhydride (TFAA) and pyridine in toluene at 60–100 °C followed by hydrolysis/decarboxylation with water at 45 °C.
Trifluoromethyl Ketones from Enolizable Carboxylic Acids via Enediolate Trifluoroacetylation/Decarboxylation
作者:Jonathan T. Reeves、Jinhua J. Song、Zhulin Tan、Heewon Lee、Nathan K. Yee、Chris H. Senanayake
DOI:10.1021/jo801737c
日期:2008.12.5
Primary and secondary (enolizable) carboxylic acids were converted in a single step to trifluoromethyl ketones. Treatment of the acid with 2.2 equiv of LDA generated an enediolate that was trifluoroacetylated with EtO2CCF3. Quenching the reaction mixture with aqueous HCI resulted in rapid decarboxylation and provided the trifluoromethyl ketone product in good yield. The process may be performed at -20 degrees C with a slight reduction in yield. The reaction was extended to the preparation of pentafluoroethyl and chlorodifluoromethyl ketones.