7152-03-6Relevant academic research and scientific papers
Aryl or heteroaryl methoxylation reaction method
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Paragraph 0106-0112, (2021/11/21)
The invention discloses an aryl or heteroaryl methoxylation reaction method. The method comprises the following steps: preparing a substrate. The coupling agent, ligand, solvent, catalyst and base are mixed homogeneously in an inert gas to give the aryl or heteroaryl methoxy compounds. Compared with a methoxylation reaction method in the prior art, the method has the advantages that the reaction system conditions are mild, the usage amount of the catalyst and the ligand is low to 5% of the amount of the substrate material, and the catalytic efficiency is improved. The method has better compatibility to different substrate expansion and discovery of aryl halides or heteroaryl halides with different functional groups. The yield of aryl or heteroaryl methoxy compounds prepared by the method disclosed by the invention is 36% - 89%.
Copper-Catalyzed Methoxylation of Aryl Bromides with 9-BBN-OMe
Li, Chen,Song, Zhi-Qiang,Wang, Dong-Hui,Wang, Jing-Ru
supporting information, p. 8450 - 8454 (2021/11/17)
A Cu-catalyzed cross-coupling reaction between aryl bromides and 9-BBN-OMe to provide aryl methyl ethers under mild conditions is reported. The oxalamide ligand BHMPO plays a key role in the transformation. Various functional groups on bromobenzenes are well tolerated, providing the desired anisole products in moderate to high yields.
B(C6F5)3-Catalyzed Hydrosilylation of Vinylcyclopropanes
He, Tao,Long, Peng-Wei,Oestreich, Martin
supporting information, p. 7383 - 7386 (2020/10/12)
A hydrosilylation of vinylcyclopropanes (VCPs) catalyzed by the strong boron Lewis acid B(C6F5)3 is reported. For the majority of VCPs, little or no ring opening of the cyclopropyl unit is observed. Conversely, for VCPs with bulky R groups, such as ortho-substituted aryl rings or branched alkyl residues, ring opening is the exclusive reaction pathway. This finding is explained by the thwarted hydride delivery to a sterically shielded, β-silicon-stabilized cyclopropylcarbinyl cation intermediate.
Electrochemical [4+2] Annulation-Rearrangement-Aromatization of Styrenes: Synthesis of Naphthalene Derivatives
Ma, Yueyue,Lv, Jufeng,Liu, Chengyu,Yao, Xiantong,Yan, Guoming,Yu, Wei,Ye, Jinxing
supporting information, p. 6756 - 6760 (2019/04/17)
We report the first electrochemical strategy to synthesize functionalized naphthalene derivatives through [4+2] annulation—rearrangement–aromatization from styrenes under mild conditions. The electrolysis does not require metals, oxidants and high valence substrates, indicating the atom and step-economy ideals. The dehydrodimer produced through [4+2] cycloaddition of 4-methoxy α-methyl styrene is isolated and proved to be the key intermediate for the following oxydehydrogenation to form carbon cation, which undergoes rearrangement–aromatization to afford the final products. This reaction represents a powerful access to construct multi-substituted naphthalene blocks in a single step.
Generation of Aryl and Heteroaryl Magnesium Reagents in Toluene by Br/Mg or Cl/Mg Exchange
Ziegler, Dorothée S.,Karaghiosoff, Konstantin,Knochel, Paul
supporting information, p. 6701 - 6704 (2018/05/05)
The alkylmagnesium alkoxide sBuMgOR?LiOR (R=2-ethylhexyl), which was prepared as a 1.5 m solution in toluene, undergoes very fast Br/Mg exchange with aryl and heteroaryl bromides, producing aryl and heteroaryl magnesium alkoxides (ArMgOR?LiOR) in toluene. These Grignard reagents react with a broad range of electrophiles, including aldehydes, ketones, allyl bromides, acyl chlorides, epoxides, and aziridines, in good yields. Remarkably, the related reagent sBu2Mg?2 LiOR (R=2-ethylhexyl) undergoes Cl/Mg exchange with various electron-rich aryl chlorides in toluene, producing diorganomagnesium species of type Ar2Mg?2 LiOR, which react well with aldehydes and allyl bromides.
Hydrogen bond donor solvents enabled metal and halogen-free Friedel–Crafts acylations with virtually no waste stream
Liu, Guangchang,Xu, Bo
supporting information, p. 869 - 872 (2018/02/09)
We have developed a metal and halogen-free Friedel–Crafts acylation protocol with virtually no waste stream generation. We propose a hydrogen bonding donor solvent will form a hydrogen bonding network and may provide significant rate enhancement for Friedel–Crafts reactions. Trifluoroacetic acid is one of the strongest H-bond donor solvents, which is also volatile and can be easily recovered by distillation without need for reaction workup. Our protocol is a ‘green’ Friedel–Crafts acylation process: 1) the catalyst can be recovered and reused; 2) using halogen free starting material (carboxylic acids anhydride or carboxylic acids); 3) no need for aqueous reaction work-up; 4) minimum or no waste steam generation.
Mild Ring Contractions of Cyclobutanols to Cyclopropyl Ketones via Hypervalent Iodine Oxidation
Sun, Yan,Huang, Xin,Li, Xiaojin,Luo, Fan,Zhang, Lei,Chen, Mengyuan,Zheng, Shiya,Peng, Bo
, p. 1082 - 1087 (2018/01/27)
An iodine-mediated oxidative ring contraction of cyclobutanols has been developed. The reaction allows the synthesis of a wide range of aryl cyclopropyl ketones under mild and eco-friendly conditions. A variety of functional groups including aromatic or alkyl halides, ethers, esters, ketones, alkenes, and even aldehydes are nicely tolerated in the reaction. This is in contrast with traditional synthetic approaches for which poor functional group tolerance is often a problem. The practicality of the method is also highlighted by the tunability of iodine oxidation system. Specifically, combining the iodine(III) reagent with an appropriate base allows the reaction to accommodate a range of challenging electron-rich arene substrates. The facile scalability of this reaction is also exhibited herein. (Figure presented.).
P -Selective (sp2)-C-H functionalization for an acylation/alkylation reaction using organic photoredox catalysis
Pandey, Ganesh,Tiwari, Sandip Kumar,Singh, Bhawana,Vanka, Kumar,Jain, Shailja
supporting information, p. 12337 - 12340 (2017/11/20)
p-Selective (sp2)-C-H functionalization of electron rich arenes has been achieved for acylation and alkylation reactions, respectively, with acyl/alkylselenides by organic photoredox catalysis involving an interesting mechanistic pathway.
Another Role of Copper in the SimmonsSmith Reaction: Copper-catalyzed Nucleophilic Michael-type Cyclopropanation of a,β-Unsaturated Ketones
Fujii, Kanami,Misaki, Tomonori,Sugimura, Takashi
, p. 634 - 636 (2014/05/20)
Cyclopropanation was performed using the Furukawa procedure with CH2I2/Et2Zn and a,β-unsaturated ketones. The reaction was performed in the presence of a copper salt. The reactivity was highly dependent on the substrate structure, and cyclopropanated products were obtained in better yields than those achieved using the original SimmonsSmith conditions with a ZnCu couple in some cases. Stereospecificity was observed in a certain case; however, the synthesis of an asymmetric version with a chiral ligand was not successful.
Catalytic Friedel-Crafts acylation: Magnetic nanopowder CuFe 2O4 as an efficient and magnetically separable catalyst
Parella, Ramarao,Naveen,Kumar, Amit,Babu, Srinivasarao Arulananda
, p. 1738 - 1742 (2013/03/28)
Catalytic regioselective Friedel-Crafts acylation of an array of anisoles/arenes with various acid chlorides using 5-20 mol % of magnetic nanopowder CuFe2O4 is reported. Unlike the conventional Friedel-Crafts reactions, which are catalyzed by moisture sensitive homogeneous catalysts/promoters, the nanopowder CuFe2O4 catalyst is moisture insensitive and the product/ketone-catalyst isolation is easily achieved using the magnetic properties of CuFe2O4.
