10282-30-1Relevant articles and documents
Ni(COD)(DQ): An Air-Stable 18-Electron Nickel(0)–Olefin Precatalyst
Apolinar, Omar,Derosa, Joseph,Eastgate, Martin D.,Engle, Keary M.,Joannou, Matthew V.,Li, Zi-Qi,Tran, Van T.,Wisniewski, Steven R.
, p. 7409 - 7413 (2020)
We report that Ni(COD)(DQ) (COD=1,5-cyclooctadiene, DQ=duroquinone), an air-stable 18-electron complex originally described by Schrauzer in 1962, is a competent precatalyst for a variety of nickel-catalyzed synthetic methods from the literature. Due to its apparent stability, use of Ni(COD)(DQ) as a precatalyst allows reactions to be conveniently performed without use of an inert-atmosphere glovebox, as demonstrated across several case studies.
The first catalytic method for Heck alkynylation of unactivated aryl bromides (copper-free Sonogashira) in an ionic liquid: 1 mol-% palladium/triphenylphosphane/pyrrolidine in [BMIM][BF4] as a simple, inexpensive and recyclable system
Hierso, Jean-Cyrille,Boudon, Julien,Picquet, Michel,Meunier, Philippe
, p. 583 - 587 (2007)
Herein we report the studies of Heck alkynylation (copper-free Sonogashira) with aryl halides (I, Br, Cl) employing various metallic precursors, tertiary phosphanes and bases in [BMIM][BF4] as the solvent. As a result, we provide the first method that allows the coupling of a large array of substrates, either activated or deactivated bromides in an ionic liquid. Furthermore, the system of highest efficiency is unexpectedly the simplest and cheaper combination that employs [Pd(η3-C3H 5)Cl]2/PPh3 at only a 1 mol-% loading with pyrrolidine as the base and in the absence of a copper salt. The coupling of sterically and electronically deactivated bromides bearing different functional groups to aryl- and alkyl acetylenes, as well as the possibility of recycling, make these results of high interest to the future development of Heck-and Sonogashira-type reactions in ionic liquids. Wiley-VCH Verlag GmbH & Co. KGaA.
[Bmim]PF6 and BF4 ionic liquids as novel and recyclable reaction media for aromatic amination
Yadav,Reddy,Basak,Venkat Narsaiah
, p. 2217 - 2220 (2003)
Activated aryl halides undergo smooth nucleophilic substitution reactions with secondary amines in 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim]PF6) or 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4) ionic liquids (ILs) at room temperature to afford the corresponding arylamines in excellent yields under mild and neutral conditions.
Organocatalytic Cascade β-Functionalization/Aromatization of Pyrrolidines via Double Hydride Transfer
An, Xiao-De,Li, Xian-Jiang,Liu, Qing,Shao, Chang-Lun,Xiao, Jian,Yang, Shuo,Zhou, Lan
, (2020)
An unprecedented cascade β-functionalization/aromatization reaction of N-arylpyrrolidines was established. A series of β-substituted arylpyrroles embedded with trifluoromethyl groups are provided directly from N-arylpyrrolidines. The deuterium-labeling experiments indicate that sequential double hydride transfer processes serve as the key steps in this transformation.
Ad Hoc Adjustment of Photoredox Properties by the Late-Stage Diversification of Acridinium Photocatalysts
Hutskalova, Valeriia,Sparr, Christof
, p. 5143 - 5147 (2021)
The steadily growing interest in substituting precious-metal photoredox catalysts with organic surrogates is vibrantly sustained by emerging methodologies to vary their photochemical behavior. Herein, we report an ad hoc approach for the preparation of acridinium salts with a particularly broad range of photoredox properties. The method involves an aryne-imine-aryne coupling to a linchpin tetrafluoro acridinium salt for a late-stage diversification by nucleophilic aromatic substitution reactions to form diaminoacridinium and undescribed aza-rhodol photocatalysts. The different functionalities and redox properties of the organic acridinium photocatalysts render them suitable for bifunctional photoredox catalysis and organocatalytic photochemical C-N cross-couplings.
Electrochemical Cross-Dehydrogenative Aromatization Protocol for the Synthesis of Aromatic Amines
Tao, Shao-Kun,Chen, Shan-Yong,Feng, Mei-Lin,Xu, Jia-Qi,Yuan, Mao-Lin,Fu, Hai-Yan,Li, Rui-Xiang,Chen, Hua,Zheng, Xue-Li,Yu, Xiao-Qi
supporting information, p. 1011 - 1016 (2022/02/05)
The introduction of amines onto aromatics without metal catalysts and chemical oxidants is synthetically challenging. Herein, we report the first example of an electrochemical cross-dehydrogenative aromatization (ECDA) reaction of saturated cyclohexanones and amines to construct anilines without additional metal catalysts and chemical oxidants. This reaction exhibits a broad scope of cyclohexanones including heterocyclic ketones, affording a variety of aromatic amines with various functionalities, and shows great potential in the synthesis of biologically active compounds.
peri-Xanthenoxanthene (PXX): a Versatile Organic Photocatalyst in Organic Synthesis
Pezzetta, Cristofer,Folli, Andrea,Matuszewska, Oliwia,Murphy, Damien,Davidson, Robert W. M.,Bonifazi, Davide
supporting information, p. 4740 - 4753 (2021/04/09)
Recent years have witnessed a continuous development of photocatalysts to satisfy the growing demand of photophysical and redox properties in photoredox catalysis, with complex structures or alternative strategies devised to access highly reducing or oxidising systems. We report herein the use of peri-xanthenoxanthene (PXX), a simple and inexpensive dye, as an efficient photocatalyst. Its highly reducing excited state allows activation of a wide range of substrates, thus triggering useful radical reactions. Benchmark transformations such as the addition of organic radicals, generated by photoreduction of organic halides, to radical traps are initially demonstrated. More complex dual catalytic manifolds are also shown to be accessible: the β-arylation of cyclic ketones is successful when using a secondary amine as organocatalyst, while cross-coupling reactions of aryl halides with amines and thiols are obtained when using a Ni co-catalyst. Application to the efficient two-step synthesis of the expensive fluoro-tetrahydro-1H-pyrido[4,3-b]indole, a crucial synthetic intermediate for the investigational drug setipiprant, has been also demonstrated. (Figure presented.).
I2/NaH2PO2-mediated deoxyamination of cyclic ethers for the synthesis of: N -aryl-substituted azacycles
Chen, Tieqiao,Huang, Tianzeng,Li, Chunya,Li, Dongyang,Lin, Ying,Liu, Long,Tang, Zhi,Zhang, Jingjing
supporting information, p. 21011 - 21014 (2021/12/04)
We have developed a protocol for efficient synthesis of N-aryl-substituted azacycles from aryl amines and cyclic ethers using I2/NaH2PO2 as the mediator. A diverse range of aryl amines and cyclic ethers undergo amination reaction to generate products in good to excellent yields with good functional group tolerance. This reaction can be easily scaled up to give N-aryl-substituted azacycles on a gram scale. Further chemical manipulation of the products enabled useful transformations of the quinoline ring, including bromination and acetylation. This journal is
Dehydrogenation/(3+2) Cycloaddition of Saturated Aza-Heterocycles via Merging Organic Photoredox and Lewis Acid Catalysis
Xiao, Teng-Fei,Zhang, Yi-Fan,Hou, Wen-Tao,Yan, Pen-Ji,Hai, Jun,Xu, Peng-Fei,Xu, Guo-Qiang
supporting information, p. 8942 - 8946 (2021/11/24)
Herein, we report a photoinduced dehydrogenation/(3+2) cycloaddition reaction by merging organic photoredox and Lewis acid catalysis, providing a straightforward and efficient approach for directly installing a benzofuran skeleton on the saturated aza-heterocycles. In this protocol, we also describe a novel organic photocatalyst (t-Bu-DCQ) with the advantages of a wider redox potential, easy synthesis, and a low price. Furthermore, the stepwise activation mechanism of dual C(sp3)-H bonds was demonstrated by a series of experimental and computational studies.
Organic photoredox catalytic α-C(sp3)-H phosphorylation of saturated: Aza -heterocycles
Yi, Ming-Jun,Xiao, Teng-Fei,Li, Wen-Hui,Zhang, Yi-Fan,Yan, Pen-Ji,Zhang, Baoxin,Xu, Peng-Fei,Xu, Guo-Qiang
supporting information, p. 13158 - 13161 (2021/12/16)
A metal-free C(sp3)-H phosphorylation of saturated aza-heterocycles via the merger of organic photoredox and Br?nsted acid catalyses was established under mild conditions. This protocol provided straightforward and economic access to a variety of valuable α-phosphoryl cyclic amines by using commercially available diarylphosphine oxide reagents. In addition, the D-A fluorescent molecule DCQ was used for the first time as a photocatalyst and exhibited an excellent photoredox catalytic efficiency in this transformation. A series of mechanistic experiments and DFT calculations demonstrated that this transformation underwent a sequential visible light photoredox catalytic oxidation/nucleophilic addition process.
