23450-30-8Relevant academic research and scientific papers
Synergy between supported ionic liquid-like phases and immobilized palladium N-heterocyclic carbene–phosphine complexes for the Negishi reaction under flow conditions
Alcázar, Jesús,García-Verdugo, Eduardo,Luis, Santiago V.,Macia, María,Peris, Edgar,Porcar, Raúl
, p. 1924 - 1935 (2020)
The combination of supported ionic liquids and immobilized NHC–Pd–RuPhos led to active and more stable systems for the Negishi reaction under continuous flow conditions than those solely based on NHC–Pd–RuPhos. The fine tuning of the NHC–Pd catalyst and the SILLPs is a key factor for the optimization of the release and catch mechanism leading to a catalytic system easily recoverable and reusable for a large number of catalytic cycles enhancing the long-term catalytic performance.
Aromatization as an Impetus to Harness Ketones for Metallaphotoredox-Catalyzed Benzoylation/Benzylation of (Hetero)arenes
Lee, Shao-Chi,Li, Li-Yun,Tsai, Zong-Nan,Lee, Yi-Hsin,Tsao, Yong-Ting,Huang, Pin-Gong,Cheng, Cheng-Ku,Lin, Heng-Bo,Chen, Ting-Wei,Yang, Chung-Hsin,Chiu, Cheng-Chau,Liao, Hsuan-Hung
, p. 85 - 89 (2022/01/04)
Herein we report ketones as feedstock materials in radical cross-coupling reactions under Ni/photoredox dual catalysis. In this approach, simple condensation first converts ketones into prearomatic intermediates that then act as activated radical sources for cross-coupling with aryl halides. Our strategy enables the direct benzylation/benzoylation of (hetero)arenes under mild reaction conditions with high functional group tolerance.
Nickel-Catalyzed Reductive Cross-Coupling of Benzylic Sulfonium Salts with Aryl Iodides
Wang, Wei,Wu, Fan,Yao, Ken
, p. 361 - 366 (2022/03/07)
A nickel-catalyzed cross-electrophile coupling of benzylic sulfonium salts with aryl iodides has been developed, providing direct access to diarylalkanes from readily available and stable coupling partners. Preliminary mechanistic studies suggest that the C-S bond cleavage proceeds through a single-electron transfer process to generate a benzylic radical.
Desulfurative Ni-Catalyzed Reductive Cross-Coupling of Benzyl Mercaptans/Mercaptoacetates with Aryl Halides
Chan, Cheng-Lin,Hsu, Che-Ming,Lee, Shao-Chi,Li, Li-Yun,Liao, Hsuan-Hung,Mi?oza, Shinje,Tsai, Hao-En,Tsai, Zong-Nan,Tsao, Yong-Ting
, (2022/02/07)
The C-S activation and sulfur removal from native thiols is challenging, which limits their application as feedstock materials in organic synthesis despite their natural abundance. Herein, we introduce a per-/polyfluoroaryl moiety, which serves as a redox-active scaffold, into sp3-hybridized thiols to activate the C-S bond. Using a Ni catalyst with MgBr2 as an additive, the S group can be removed to yield an aliphatic radical that can react with an aryl halide in a reductive cross-coupling.
Electrochemically Enabled, Nickel-Catalyzed Dehydroxylative Cross-Coupling of Alcohols with Aryl Halides
Li, Zijian,Sun, Wenxuan,Wang, Xianxu,Li, Luyang,Zhang, Yong,Li, Chao
supporting information, p. 3536 - 3543 (2021/03/08)
As alcohols are ubiquitous throughout chemical science, this functional group represents a highly attractive starting material for forging new C-C bonds. Here, we demonstrate that the combination of anodic preparation of the alkoxy triphenylphosphonium ion and nickel-catalyzed cathodic reductive cross-coupling provides an efficient method to construct C(sp2)-C(sp3) bonds, in which free alcohols and aryl bromides - both readily available chemicals - can be directly used as coupling partners. This nickel-catalyzed paired electrolysis reaction features a broad substrate scope bearing a wide gamut of functionalities, which was illustrated by the late-stage arylation of several structurally complex natural products and pharmaceuticals.
Nickel-Catalyzed Electrochemical C(sp3)?C(sp2) Cross-Coupling Reactions of Benzyl Trifluoroborate and Organic Halides**
Luo, Jian,Hu, Bo,Wu, Wenda,Hu, Maowei,Liu, T. Leo
, p. 6107 - 6116 (2021/02/01)
Reported here is the redox neutral electrochemical C(sp2)?C(sp3) cross-coupling reaction of bench-stable aryl halides or β-bromostyrene (electrophiles) and benzylic trifluoroborates (nucleophiles) using nonprecious, bench-stable NiCl2?glyme/polypyridine catalysts in an undivided cell configuration under ambient conditions. The broad reaction scope and good yields of the Ni-catalyzed electrochemical coupling reactions were confirmed by 50 examples of aryl/β-styrenyl chloride/bromide and benzylic trifluoroborates. Potential applications were demonstrated by electrosynthesis and late-stage functionalization of pharmaceuticals and natural amino acid modification, and three reactions were run on gram-scale in a flow-cell electrolyzer. The electrochemical C?C cross-coupling reactions proceed through an unconventional radical transmetalation mechanism. This method is highly productive and expected to find wide-spread applications in organic synthesis.
Dynamic Kinetic Cross-Electrophile Arylation of Benzyl Alcohols by Nickel Catalysis
Guo, Peng,Wang, Ke,Jin, Wen-Jie,Xie, Hao,Qi, Liangliang,Liu, Xue-Yuan,Shu, Xing-Zhong
supporting information, p. 513 - 523 (2021/01/12)
Catalytic transformation of alcohols via metal-catalyzed cross-coupling reactions is very important, but it typically relies on a multistep procedure. We here report a dynamic kinetic cross-coupling approach for the direct functionalization of alcohols. The feasibility of this strategy is demonstrated by a nickel-catalyzed cross-electrophile arylation reaction of benzyl alcohols with (hetero)aryl electrophiles. The reaction proceeds with a broad substrate scope of both coupling partners. The electron-rich, electron-poor, and ortho-/meta-/para-substituted (hetero)aryl electrophiles (e.g., Ar-OTf, Ar-I, Ar-Br, and inert Ar-Cl) all coupled well. Most of the functionalities, including aldehyde, ketone, amide, ester, nitrile, sulfone, furan, thiophene, benzothiophene, pyridine, quinolone, Ar-SiMe3, Ar-Bpin, and Ar-SnBu3, were tolerated. The dynamic nature of this method enables the direct arylation of benzylic alcohol in the presence of various nucleophilic groups, including nonactivated primary/secondary/tertiary alcohols, phenols, and free indoles. It thus offers a robust alternative to existing methods for the precise construction of diarylmethanes. The synthetic utility of the method was demonstrated by a concise synthesis of biologically active molecules and by its application to peptide modification and conjugation. Preliminary mechanistic studies revealed that the reaction of in situ formed benzyl oxalates with nickel, possibly via a radical process, is an initial step in the reaction with aryl electrophiles.
Visible Light-Catalyzed Benzylic C-H Bond Chlorination by a Combination of Organic Dye (Acr+-Mes) and N-Chlorosuccinimide
Xiang, Ming,Zhou, Chao,Yang, Xiu-Long,Chen, Bin,Tung, Chen-Ho,Wu, Li-Zhu
, p. 9080 - 9087 (2020/08/14)
By combining "N-chlorosuccinimide (NCS)"as the safe chlorine source with "Acr+-Mes"as the photocatalyst, we successfully achieved benzylic C-H bond chlorination under visible light irradiation. Furthermore, benzylic chlorides could be converted to benzylic ethers smoothly in a one-pot manner by adding sodium methoxide. This mild and scalable chlorination method worked effectively for diverse toluene derivatives, especially for electron-deficient substrates. Careful mechanistic studies supported that NCS provided a hydrogen abstractor "N-centered succinimidyl radical,"which was responsible for the cleavage of the benzylic C-H bond, relying on the reducing ability of Acr?-Mes.
Upscaling Photoredox Cross-Coupling Reactions in Batch Using Immersion-Well Reactors
Candish, Lisa,Collins, Karl D.,Grimm, Isabelle,Hauer, Simone T.,Lovis, Kai,Schulte, Tim,Wycich, Gina
supporting information, p. 1185 - 1193 (2020/07/08)
Herein we describe a straightforward approach for the scale-up of photoredox cross-coupling reactions from milligram to multigram scale using immersion-well batch reactors with minimal reoptimization of the reaction conditions. This approach can be applied to both homogeneous and, more significantly, heterogeneous reaction mixtures. Furthermore, we have used an immersion-well side-loop reactor to perform a reaction on a 400 mmol scale (86 g of aryl bromide).
PHOTOCATALYST SYSTEM AND USE THEREOF IN A PHOTOCATALYTIC PROCESS
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Page/Page column 33; 35; 37, (2019/06/13)
Photocatalyst system and use thereof in a photochemical process The invention relates to a photocatalyst system comprising, in the absence of a further photosensitizer other than the compound of formula (III) or a mixture thereof: (i) a nickel(II) salt, (
