Synthesis of α-Halo-α,α-difluoromethyl Ketones by a Trifluoroacetate Release/Halogenation Protocol
摘要:
Three series of alpha-halo-alpha,alpha-difluoromethyl ketones are prepared from highly alpha-fluorinated gem-dials by exploiting the facile release of trifluoroacetate, followed by immediate trapping of the liberated alpha,alpha-difluoroenolate with an electrophilic chlorine, bromine, or iodine source. The products are typically isolated in good yields, even in the case of sensitive, alpha-iodo-alpha,alpha-difluoromethyl ketones. Also, we demonstrate that an alpha-iodo-alpha,alpha-difluoromethyl ketone will participate in a copper-promoted reaction to forge a new carbon-carbon bond.
Gold-Catalyzed Highly Selective Photoredox C(sp<sup>2</sup>
)−H Difluoroalkylation and Perfluoroalkylation of Hydrazones
作者:Jin Xie、Tuo Zhang、Fei Chen、Nina Mehrkens、Frank Rominger、Matthias Rudolph、A. Stephen K. Hashmi
DOI:10.1002/anie.201508622
日期:2016.2.18
hydrazones are highly functionalized, versatile molecules. A mild reduction of the coupling products can efficiently produce gem‐difluoromethylated β‐amino phosphonic acids and β‐amino acid derivatives. In mechanistic studies, a difluoroalkyl radical intermediate was detected by an EPR spin‐trappingexperiment, indicating that a gold‐catalyzed radical pathway is operating.
据报道,使用容易获得的R F -Br试剂,gold的金催化光氧化还原C(sp 2)-H二氟烷基化和hydr的全氟烷基化。所得的宝石二氟甲基化和全氟烷基化的azo是高度官能化的多用途分子。偶合产物的轻度减少可以有效地生产出宝石-二氟甲基化的β-氨基膦酸和β-氨基酸衍生物。在机理研究中,通过EPR自旋捕获实验检测到二氟烷基自由基中间体,表明金催化的自由基途径正在起作用。
Metal-Mediated Reformatsky Reaction of Bromodifluoromethyl Ketone and Imine
作者:Chun-Ru Cao、Min Jiang、Jin-Tao Liu
DOI:10.1002/ejoc.201403424
日期:2015.2
The Reformatsky reaction of bromodifluoromethyl ketones and imines took place readily in the presence of Zn/CuCl at room temperature to afford β-amino α,α-difluoro ketones in good yields. Using (S)-tert-butanesulfinyl as a chiral auxiliary, the asymmetric Reformatsky reaction was also achieved and found to proceed with excellent diastereoselectivities. A plausible model is proposed to account for the
Regioselective Synthesis of Emission Color‐Tunable Pyrazolo[1,5‐a]pyrimidines with β,β‐Difluoro Peroxides as 1,3‐Bis‐Electrophiles
作者:Yangyang Ma、Yuanjin Chen、Leiyang Lv、Zhiping Li
DOI:10.1002/adsc.202100298
日期:2021.7
The synthesis and photophysical properties of fluorescent pyrazolo[1,5-a]pyrimidines (PPs) are explored. An array of 5,7-disubstituted fluorescent PPs are prepared selectively by using β,β-difluoro peroxides as the 1,3-bis-electrophiles. The synthesized PPs display a fairly significant stokes shift (up to 211 nm) and a large window of tunable emission wavelength that covers most of the visible spectrum
Photoinduced Cascade C–N/C═O Bond Formation from Bromodifluoroalkyl Reagents, Amines, and H<sub>2</sub>O via a Triple-Cleavage Process
作者:Xiaohui Zhuang、Lan Ling、Yingying Wang、Bingqian Li、Bin Sun、Weike Su、Can Jin
DOI:10.1021/acs.orglett.2c00233
日期:2022.3.4
A green, sustainable, and straightforward method for the synthesis of unsymmetrical oxalamides via photoinduced C–N/C═O bond formation of bromodifluoroacetamide, amine, and H2O through a triple-cleavage process has been developed. In addition, this approach also provides access to the known bioactive compounds, and a feasible reaction mechanism is proposed. Moreover, the advantages of this transformation
已经开发出一种绿色、可持续和直接的方法,通过三裂解过程光诱导溴二氟乙酰胺、胺和 H 2 O形成 C-N/C=O 键来合成不对称草酰胺。此外,该方法还提供了对已知生物活性化合物的访问,并提出了可行的反应机制。此外,这种转化的优势,包括温和的反应条件、广泛的底物范围和操作简单,使该协议对进一步的应用具有吸引力。
Metal-mediated Reformatsky reaction of bromodifluoromethyl ketone and aldehyde using water as solvent
作者:Hui Yao、Chun-Ru Cao、Min Jiang、Jin-Tao Liu
DOI:10.1016/j.jfluchem.2013.08.012
日期:2013.12
Water is demonstrated as a suitable solvent for an efficient and environmentally friendly method for the synthesis of α,α-difluorinated β-hydroxy carbonyl compounds through the Reformatsky reaction of bromodifluoromethyl ketones with aldehydes in the presence of Zn/CuCl at room temperature.