Fluorinated Building Blocks. The Discovery of a Stable Difluoroallenyl Indium and the Synthesis of <i>g</i><i>em</i>-Difluoroallenyl and -propargyl Synthons in Aqueous Media
作者:ZhiGang Wang、Gerald B. Hammond
DOI:10.1021/jo000832f
日期:2000.10.1
The synthesis of two highly functional fluorinated motifs, TIPS-C triple bond C-CF2-, and CF2=C=C(TIPS)- is described. This approach is mediated by a room-temperature stable ethereal solution of a difluoroallene indium intermediate. This intermediate may be used as "stock solution" in the reaction with aqueous HCHO, to yield CF2=C=C(TIPS)CH2OH, and in a reaction with a Schiff base to produce the corresponding
描述了两个功能性高的氟化基序TIPS-C三键C-CF2-和CF2 = C = C(TIPS)-的合成。这种方法是由室温稳定的二氟丙烯烯铟中间体的乙醚溶液介导的。该中间体可以在与HCHO水溶液反应中用作“原液”,以产生CF 2 = C = C(TIPS)CH 2 OH,并且在与席夫碱反应中以产生相应的β,β-二氟高炔丙基胺。CF2 = C = C(TIPS)CH2-OH的合成潜力已通过简便有效的5-内-trig环化反应转化为二氟二氢呋喃衍生物得到了证明。通过在主要为水的介质中将铟加到醛和TIPS-C三键C-CF2Br的混合物中,可以合成同炔的宝石二氟醇。
Copper-Catalyzed Synthesis of Difluoromethyl Alkynes from Terminal and Silyl Acetylenes
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。
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.