描述了在碱性条件下使用(溴二氟甲基)膦酸二乙酯 ( 1 )对各种基于S - 和O - 的亲核试剂进行有效二氟甲基化,呈现出广泛的 p K a值。这些反应依赖于通过1水解形成的二氟卡宾的定量产生,发现只有当起始材料的 p K a值小于约1时才有效。11. 重要的是,在底物具有两个或三个亲核中心的情况下,该特征成功实现以实现中心的高化学或区域选择性二氟甲基化,表现出最低的 p K一个值和最高极化。
Deoxygenative <i>gem</i>-difluoroolefination of carbonyl compounds with (chlorodifluoromethyl)trimethylsilane and triphenylphosphine
作者:Fei Wang、Lingchun Li、Chuanfa Ni、Jinbo Hu
DOI:10.3762/bjoc.10.32
日期:——
phosphonium ylide represents one of the most straightforward methods. RESULTS: The combination of (chlorodifluoromethyl)trimethylsilane (TMSCF2Cl) and triphenylphosphine (PPh3) can be used for the synthesis of gem-difluoroolefins from carbonyl compounds. Comparative experiments demonstrate that TMSCF2Cl is superior to (bromodifluoromethyl)trimethylsilane (TMSCF2Br) and (trifluoromethyl)trimethylsilane
Difluoromethyl 2-Pyridyl Sulfone: A New <i>gem-</i>Difluoroolefination Reagent for Aldehydes and Ketones
作者:Yanchuan Zhao、Weizhou Huang、Lingui Zhu、Jinbo Hu
DOI:10.1021/ol100090r
日期:2010.4.2
Difluoromethyl2-pyridylsulfone, a previously unknown compound, was found to act as a novel and efficient gem-difluoroolefination reagent for both aldehydes and ketones. It was found that the fluorinated sulfinate intermediate in the reaction is relatively stable, which can be observed by 19F NMR and trapped with CH3I.
发现二氟甲基2-吡啶基砜(一种以前未知的化合物)可同时作为醛和酮的新型高效二氟烯烃聚合试剂。发现反应中的氟化亚磺酸盐中间体相对稳定,这可以通过19 F NMR观察到并被CH 3 I捕获。
Synthesis of<i>gem</i>-Difluorocyclopropa(e)nes and O<i>-</i>, S<i>-</i>, N<i>-</i>, and P-Difluoromethylated Compounds with TMSCF<sub>2</sub>Br
作者:Lingchun Li、Fei Wang、Chuanfa Ni、Jinbo Hu
DOI:10.1002/anie.201306703
日期:2013.11.18
Two-in-one: Me3 SiCF2 Br is an efficient difluorocarbene source and is compatible with both neutral and aqueous basic conditions. Bromide-ion-initiated [2+1] cycloaddition with alkenes/alkynes and hydroxide ion promoted α-addition with (thio)phenols, (thio)alcohols, sulfinates, heterocyclic amines, and H-phosphine oxides give the corresponding gem-difluorinated compounds with broad functional-group tolerance.
Carbonyl olefination of diaryl ketones with heteroaryl sulfoxides
作者:Bing Gao、Jingyu Hu、Yanchuan Zhao、Jinbo Hu
DOI:10.1016/j.tetlet.2015.05.034
日期:2015.7
Heteroaryl sulfones are capable of converting the carbonyl functionalities to alkenyl motifs, which is well-known as Julia-Kocienski olefination reaction. However, their sulfoxide analogues have failed in such an olefination reaction for over twenty years. In this Letter, we demonstrate that the heteroaryl sulfoxide-participated carbonyl olefination reaction can be realized under certain conditions. Furthermore, a novel defluorinative olefination of diaryl ketones has been achieved with 2-pyridyl sulfoxides. (C) 2015 Elsevier Ltd. All rights reserved.
<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.