Alternative Palladium-Catalyzed Vinylic C−H Difluoroalkylation of Ketene Dithioacetals Using Bromodifluoroacetate Derivatives
作者:Shuangquan Tian、Xiaoning Song、Dongsheng Zhu、Mang Wang
DOI:10.1002/adsc.201701554
日期:2018.4.3
A palladium‐catalyzedcross‐coupling of α‐oxo ketene dithioacetals and bromodifluoroacetate derivatives has been developed for the synthesis of a class of CF2‐containing tetra‐substituted olefins, which has potential to extend to drug design and material application. The process is proposed to involve two single electron transfer processes accompanied by an alternative loop from palladium(0) to palladium(I)
The Cu-catalyzed direct difluoroalkylation of aldehyde hydrazones with functionalized difluoromethyl bromides is described. The reaction yields stereodefined α,α–difluoro-β-keto hydrazones under mild conditions and can be carried out at a scale that opens up the possibility of practical applications.
S<sub>8</sub>-Catalyzed triple cleavage of bromodifluoro compounds for the assembly of N-containing heterocycles
作者:Shuilin Deng、Haohua Chen、Xingxing Ma、Yao Zhou、Kai Yang、Yu Lan、Qiuling Song
DOI:10.1039/c9sc01333d
日期:——
cleavage of three C–X bonds, including two inert C(sp3)–F bonds on bromodifluoroacetamides, while leaving C–C bonds intact. This strategy will undoubtedly further consummate the role of halo difluoro compounds and enrich both fluorine chemistry and pharmaceutical sciences.
Visible‐Light‐Promoted Oxy‐difluoroalkylation of Aryl Alkynes for the Synthesis of
<i>β</i>
‐Fluoroenones and
<i>α</i>
‐Difluoroalkyl Ketones
作者:Zhong Zhang、Xiangqian Li、Dayong Shi
DOI:10.1002/adsc.202100289
日期:2021.7
synthesis of (E)-β-fluoroenones and α-difluoroalkyl ketones have been achieved. By employing water as oxygen source, potassium carbonate as base, tetrasubstituted β-fluoroenones could be regio- and stereoselectively synthesized by oxy-difluoroalkylation of alkynes under visible light irradiated with moderate to good yields. α-Difluoroalkyl ketones could be obtained while using phenylpyridine as base
一种选择性合成( E ) -β-氟烯酮和α-二氟烷基酮的方法已经实现。以水为氧源,碳酸钾为碱,在可见光照射下,炔烃的氧二氟烷基化反应可以区域选择性和立体选择性地合成四取代的β-氟代烯酮,收率适中。以苯基吡啶为碱可制得α-二氟烷基酮。这种改造具有条件温和、功能耐受性广、步骤经济等特点。大规模转化和进一步衍生化显示了其在有机合成中的潜在应用。
Photoinduced Radical Cascade Cyclization: A Metal-Free Approach to Access Difluoroalkylated Dioxodibenzothiazepines
A simple and mild photoredox catalytic approach to access difluoroalkylated dioxodibenzothiazepines in high regioselectivity via radical cascadecyclization has been described herein. In contrast to previous methods, this strategy does not involve the use of transition-metal catalysts and avoids the potential disadvantages of inevitable toxicity and the tedious removal process of metal catalysts. The