- A Ligand-Enabled Palladium-Catalyzed Highly para-Selective Difluoromethylation of Aromatic Ketones
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A practical and highly para-selective C?H difluoromethylation of aromatic ketones has been developed by employing tetrakis(triphenylphosphine)palladium(0) as the catalyst and triphenylphosphine as the ligand. In addition to general aromatic ketones, this
- Tu, Guangliang,Yuan, Chunchen,Li, Yuting,Zhang, Jingyu,Zhao, Yingsheng
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- Ruthenium(II)-catalyzed para-selective C[sbnd]H difluoroalkylation of aromatic aldehydes and ketones using transient directing groups
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A Ru(II)-catalyzed para-difluoroalkylation of aromatic aldehydes and ketones with a transient directing group has been developed. It utilizes less expensive ruthenium catalysts and allows facile access to challenging difluoroalkylated aldehydes. The mechanism studies suggest that the distinct coordination mode of ruthenium complex with imine moieties is responsible for para-selectivity.
- Cheng, Yaohang,He, Yuhang,Zheng, Jie,Yang, Hui,Liu, Jun,An, Guanghui,Li, Guangming
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- Ruthenium(II)-Catalyzed C?H Difluoromethylation of Ketoximes: Tuning the Regioselectivity from the meta to the para Position
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A highly para-selective CAr?H difluoromethylation of ketoxime ethers under ruthenium catalysis has been developed. A wide variety of ketoxime ethers are compatible with the reaction, which leads to the corresponding para-difluoromethylated products in moderate to good yield. A mechanistic study clearly showed that chelation-assisted cycloruthenation is the key factor in the para selectivity of the difluoromethylation of ketoxime ethers. Density functional theory was used to gain a theoretical understanding of the para selectivity.#.
- Yuan, Chunchen,Zhu, Lei,Zeng, Runsheng,Lan, Yu,Zhao, Yingsheng
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- Visible-Light-Induced para-Selective C(sp2)-H Difluoroalkylation of Diverse (Hetero)aromatic Carbonyls
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An efficient visible-light-induced para-selective C(sp2)-H difluoroalkylation of diverse electron-deficient (hetero)aromatic carbonyls (aldehydes and ketones) at ambient temperature has been developed by employing Ir(ppy)3 as the catalyst and 1,10-phenanthroline as the additive. This protocol was highlighted by its wide substrate scope, high regioselectivity, low catalyst usage, and operational simplicity.
- Zhou, Jiadi,Wang, Fang,Lin, Zhihao,Cheng, Cheng,Zhang, Qiwei,Li, Jianjun
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- Generation of Axially Chiral Fluoroallenes through a Copper-Catalyzed Enantioselective β-Fluoride Elimination
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Herein we report the copper-catalyzed silylation of propargylic difluorides to generate axially chiral, tetrasubstituted monofluoroallenes in both good yields (27 examples >80%) and enantioselectivities (82-98% ee). Compared to previously reported synthetic routes to axially chiral allenes (ACAs) from prochiral substrates, a mechanistically distinct reaction has been developed: the enantiodiscrimination between enantiotopic fluorides to set an axial stereocenter. DFT calculations and vibrational circular dichroism (VCD) suggest that β-fluoride elimination from an alkenyl copper intermediate likely proceeds through a syn-β-fluoride elimination pathway rather than an anti-elimination pathway. The effects of the C1-symmetric Josiphos-derived ligand on reactivity and enantioselectivity were investigated. Not only does this report showcase that alkenyl copper species (like their alkyl counterparts) can undergo β-fluoride elimination, but this elimination can be achieved in an enantioselective fashion.
- Liu, Peng,Mai, Binh Khanh,Nafie, Jordan,O'Connor, Thomas J.,Toste, F. Dean
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supporting information
p. 13759 - 13768
(2021/09/07)
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- Synthesis method of difluoroalkyl substituted aromatic ketone compound under photocatalysis
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The invention discloses a synthesis method of a difluoroalkyl substituted aromatic ketone compound under photocatalysis. The preparation method comprises the following steps: dissolving an aromatic ketone compound, a CF2 reagent, a bidentate ligand, a pho
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Paragraph 0020
(2020/05/01)
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- Pd-Catalyzed para-selective C-H difluoromethylation of aromatic carbonyls
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A novel palladium catalyzed highly para-selective C-H difluoromethylation of electron-deficient aromatic carbonyls was developed. Diverse substituted aromatic ketones and benzoates were selectively difluoromethylated at the remote para-site of carbonyl gr
- Mao, Yang-Jie,Wang, Bing-Xin,Wu, Qiu-Zi,Zhou, Kun,Lou, Shao-Jie,Xu, Dan-Qian
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supporting information
p. 2019 - 2022
(2019/02/19)
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- Easy Access to Difluoromethylene-Containing Arene Analogues through Palladium-Catalysed C–H Olefination
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An efficient palladium-catalysed ortho-C–H olefination of α,α-difluorophenylacetic acid derivatives using 8-aminoquinoline as a bidentate directing group has been developed. A range of olefinated arenes can thus be synthesized in a concise way. This reaction provides an easy and straightforward route to a panel of difluoromethylated arene analogues in moderate to good yields, with a satisfactory tolerance of common functional groups. Transformation of the products into a variety of other difluoromethylene-containing compounds demonstrates the utility of this method.
- Shao, Changdong,Shi, Guangfa,Zhang, Yanghui
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p. 5529 - 5538
(2016/11/25)
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- Palladium-catalyzed difluoroalkylation of aryl boronic acids: A new method for the synthesis of aryldifluoromethylated phosphonates and carboxylic acid derivatives
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The palladium-catalyzed difluoroalkylation of aryl boronic acids with bromodifluoromethylphosphonate, bromodifluoroacetate, and further derivatives has been developed. This method provides a facile and useful access to a series of functionalized difluoromethylated arenes (ArCF2PO(OEt) 2, ArCF2CO2Et, and ArCF2CONR 1R2) that have important applications in drug discovery and development. Preliminary mechanistic studies reveal that a single electron transfer (SET) pathway may be involved in the catalytic cycle. Palladium does it: The palladium-catalyzed difluoroalkylation of aryl boronic acids with bromodifluoromethylphosphonate, bromodifluoroacetate, and further derivatives has been developed (see scheme). Preliminary mechanistic studies reveal that a single electron transfer (SET) pathway may be involved in the catalytic cycle. Copyright
- Feng, Zhang,Min, Qiao-Qiao,Xiao, Yu-Lan,Zhang, Bo,Zhang, Xingang
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supporting information
p. 1669 - 1673
(2014/03/21)
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- Catalytic decarboxylative fluorination for the synthesis of Tri- and difluoromethyl arenes
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Treatment of readily available α,α-difluoro- and α-fluoroarylacetic acids with Selectfluor under Ag(I) catalysis led to decarboxylative fluorination. This operationally simple reaction gave access to tri- and difluoromethylarenes applying a late-stage fluorination strategy. Translation to [18F]labeling is demonstrated using [ 18F]Selectfluor bis(triflate), a reagent affording [ 18F]tri- and [18F]difluoromethylarenes not within reach with [18F]F2.
- Mizuta, Satoshi,Stenhagen, Ida S.R.,O'Duill, Miriam,Wolstenhulme, Jamie,Kirjavainen, Anna K.,Forsback, Sarita J.,Tredwell, Matthew,Sandford, Graham,Moore, Peter R.,Huiban, Mickael,Luthra, Sajinder K.,Passchier, Jan,Solin, Olof,Gouverneur, Véronique
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supporting information
p. 2648 - 2651
(2013/07/11)
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- METHOD FOR PRODUCING AROMATIC DIFLUOROACETIC ACID ESTER
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Disclosed is a method for producing a compound having a difluoromethylene group at an even lower cost and with excellent yield. The production method of the present invention is a method for producing an aromatic difluoroacetic acid ester, which comprises reacting an iodobenzene containing an electro attracting group and an α-silyl difluoroacetic acid ester in the presence of a metal halide.
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Page/Page column 11
(2012/09/10)
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