A General Protocol for C−H Difluoromethylation of Carbon Acids with TMSCF
<sub>2</sub>
Br
作者:Qiqiang Xie、Ziyue Zhu、Lingchun Li、Chuanfa Ni、Jinbo Hu
DOI:10.1002/anie.201900763
日期:2019.5.6
efficient method for the selectiveC‐difluoromethylation of carbon acids with the reagent TMSCF2Br has been developed. A variety of structurally diverse sp3‐ and sp‐hybridized carbon nucleophiles, including esters, amides, fluorenes, terminal alkynes, β‐ketoesters, malonates, and other activated C−H nucleophiles, could be efficiently and selectively transformed into the corresponding C‐difluoromethylated
An efficient method for the direct C(sp)–H difluoromethylation of terminal alkynes and the desilylation–difluoromethylation of (trimethylsilyl)acetylenes is disclosed. The copper-catalyzed transformation provides access to a wide range of structurally diverse CF2H alkynes in good yields, utilizing a (difluoromethyl)zinc reagent and an organic oxidant. The difluoromethylation of important synthons and
公开了一种用于末端炔烃的直接 C(sp)-H 二氟甲基化和(三甲基甲硅烷基)乙炔的脱甲硅烷基化-二氟甲基化的有效方法。利用(二氟甲基)锌试剂和有机氧化剂,铜催化的转化以良好的产率提供了广泛的结构多样的 CF 2 H 炔烃。展示了重要合成子和 API 的二氟甲基化。这些 (二氟甲基) 炔烃的合成效用通过选定的环加成反应得到证明。此外,对反应条件的轻微修改允许选择性制备 2-二氟甲基吲哚。
<i>N</i>-Tosyl-<i>S</i>-difluoromethyl-<i>S</i>-phenylsulfoximine: A New Difluoromethylation Reagent for S-, N-, and C-Nucleophiles
作者:Wei Zhang、Fei Wang、Jinbo Hu
DOI:10.1021/ol900567c
日期:2009.5.21
The first alpha-difluoromethyl sulfoximine compound, 2, was successfully prepared by using the copper(II)-catalyzed nitrene transfer reaction. Compound 2 was found to be a novel and efficient difluoromethylation reagent for transferring the CF2H group to S-, N-, and C-nucleophiles. Deuterium-labeling experiments suggest that a difluorocarbene mechanism is involved in the current difluoromethylation reactions.
Siladifluoromethylation and Difluoromethylation onto C(sp<sup>3</sup>), C(sp<sup>2</sup>), and C(sp) Centers Using Ruppert–Prakash Reagent and Fluoroform
Siladifluoromethylations and difluoromethylations on sp(3), sp(2), and sp carbons of lithiated carbamates, arenes, and terminal alkynes, respectively, have been attained by employing the Ruppert-Prakash reagent (CF3TMS) and fluoroform (CF3H) as the CF2 sources. The advantage of this reaction is that the (sila)difluoromethylated compounds can be obtained by simple treatment of easily accessible substrates, lithium bases, and CF3TMS or CF3H. Furthermore, the products bearing the TMS group can be transformed into the valuable compounds with the C(F)2 fragment via the carbon-carbon bond forming reactions.