69678-00-8Relevant articles and documents
Oxidation of BINOLs by Hypervalent Iodine Reagents: Facile Synthesis of Xanthenes and Lactones
Zhang, Huaiyuan,Wirth, Thomas
, (2022/03/17)
Xanthene derivatives have broad applications in medicines, fluorescent probes, dyes, food additives, etc. Therefore, much attention was focused on developing the synthetic methods to prepare these compounds. Binaphthyl-based xanthene derivatives were prepared through the oxidation of BINOLs promoted by the hypervalent iodine reagent iodosylbenzene (PhIO). Nine-membered lactones were obtained through a similar oxidative reaction when iodoxybenzene (PhIO2) was used. Additionally, one-pot reactions of BINOLs, PhIO and nucleophiles such as alcohols and amines were also investigated to provide alkoxylated products and amides in good to excellent yields.
Accurate Understanding the Catalytic Role of MnO2 in the Oxidative-Coupling of 2-naphthols into 1,1′-bi-2-naphthols
Wu, Yuting,Yang, Long,Wu, Bo,Li, Jie,Liu, Binyao,Ke, Gaili,Dong, Faqin,Zhou, Yong,He, Huichao
, p. 901 - 908 (2020/08/17)
Abstract: It has been reported that β-MnO2 has photocatalytic activity for the oxidative-coupling of 2-naphthols into 1,1′-bi-2-naphthols. Nevertheless, it is hard to exclude the possibility that the oxidative-coupling of 2-naphthols is initiated by β-MnO2 catalysis in dark due to the insufficient investigations in the related reports. In the present work, the oxidative-coupling of 2-naphthols into 1,1′-bi-2-naphthols with different phases MnO2 catalysis in dark and under visible-light irradiation were systematically investigated. The results revealed that the oxidative-coupling of 2-naphthols is jointly initiated by MnO2 catalysis and O2-oxidation, not by MnO2 photocatalysis. Among the α-MnO2, β-MnO2, γ-MnO2 and δ-MnO2 catalysis, β-MnO2 catalysis has the optimal performance, its selectivity for the oxidative-coupling of 2-naphthols into 1,1′-bi-2-naphthols is close to 100%, and its catalytic capacity could be well retained after multiple using. Our findings provide comprehensive and accurate understanding the catalytic role of MnO2 for the oxidative-coupling of 2-naphthols into 1,1′-bi-2-naphthols. Graphic Abstract: In the present work, the oxidative-coupling of 2-naphthols into 1,1′-bi-2-naphthols was proved to be jointly initiated by MnO2 catalysis and O2-oxidation, not by MnO2 photocatalysis. β-MnO2 has the optimal catalytic activity for the oxidative-coupling of 2-naphthols relative to α-MnO2, γ-MnO2 and δ-MnO2. [Figure not available: see fulltext.]
Enantioselective Synthesis of 3,3′-Disubstituted 2-Amino-2′-hydroxy-1,1′-binaphthyls by Copper-Catalyzed Aerobic Oxidative Cross-Coupling
Zhao, Xiao-Jing,Li, Zi-Hao,Ding, Tong-Mei,Tian, Jin-Miao,Tu, Yong-Qiang,Wang, Ai-Fang,Xie, Yu-Yang
, p. 7061 - 7065 (2021/02/27)
A challenging direct asymmetric catalytic aerobic oxidative cross-coupling of 2-naphthylamine and 2-naphthol, using a novel CuI/SPDO system, has been successfully developed for the first time. Enantioenriched 3,3′-disubstituted NOBINs were achieved and could be readily derived to divergent chiral ligands and catalysts. This reaction features high enantioselectivities (up to 96 % ee) and good yields (up to 80 %). The DFT calculations suggest that the F–H interactions between CF3 of L17 and H-1,8 of 2-naphthol, and the π–π stacking between the two coupling partners could play vital roles in the enantiocontrol of this cross-coupling reaction.
Synthesis of Polysubstituted 2-Naphthols by Palladium-Catalyzed Intramolecular Arylation/Aromatization Cascade
Cai, Jinhui,Hu, Xu-Dong,Liu, Wen-Bo,Wang, Zhen-Kai,Yao, Fei,Zhang, Yun-Hao
supporting information, (2020/02/25)
A palladium-catalyzed intramolecular α-arylation and defluorinative aromatization strategy for the synthesis of polysubstituted 2-naphthols is reported. With ortho-bromobenzyl-substituted α-fluoroketones as the substrates and palladium acetate/triphenylphosphine as the catalyst, this method features good functional group tolerance, readily available catalyst and starting materials, and high yields. The applications of the strategy are demonstrated by the synthesis of useful building blocks, such as naphtha[2,3-b]furan, naphthol AS-D, and ligands/catalysts. (Figure presented.).
Isothiourea-Catalysed Regioselective Acylative Kinetic Resolution of Axially Chiral Biaryl Diols
Qu, Shen,Greenhalgh, Mark D.,Smith, Andrew D.
supporting information, p. 2816 - 2823 (2019/02/05)
An operationally simple isothiourea-catalysed acylative kinetic resolution of unprotected 1,1′-biaryl-2,2′-diol derivatives has been developed to allow access to axially chiral compounds in highly enantioenriched form (s values up to 190). Investigation of the reaction scope and limitations provided three key observations: i) the diol motif of the substrate was essential for good conversion and high s values; ii) the use of an α,α-disubstituted mixed anhydride (2,2-diphenylacetic pivalic anhydride) was critical to minimize diacylation and give high selectivity; iii) the presence of substituents in the 3,3′-positions of the diol hindered effective acylation. This final observation was exploited for the highly regioselective acylative kinetic resolution of unsymmetrical biaryl diol substrates bearing a single 3-substituent. Based on the key observations identified, acylation transition state models have been proposed to explain the atropselectivity of this kinetic resolution.
The Interrupted Pummerer Reaction in a Sulfoxide-Catalyzed Oxidative Coupling of 2-Naphthols
He, Zhen,Pulis, Alexander P.,Procter, David J.
supporting information, p. 7813 - 7817 (2019/05/15)
A benzothiophene S-oxide catalyst, generated in situ by sulfur oxidation with H2O2, mediates the oxidative coupling of 2-naphthols. Key to the catalytic process is the capture and inversion of reactivity of a 2-naphthol partner, using an interrupted Pummerer reaction of an unusual benzothiophene S-oxide, followed by subsequent coupling with a second partner. The new catalytic manifold has been showcased in the synthesis of the bioactive natural products, (±)-nigerone and (±)-isonigerone. Although Pummerer reactions are used widely, their application in catalysis is rare, and our approach represents a new catalytic manifold for metal-free C?C bond formation.
Photochemical Oxidative Coupling of 2-Naphthols using a Hybrid Reduced Graphene Oxide/Manganese Dioxide Nanocomposite under Visible-Light Irradiation
Kumar, Anurag,Aathira,Pal, Ujjwal,Jain, Suman L.
, p. 1844 - 1852 (2018/02/12)
We describe a simple, cost-effective, efficient, and high-yielding photocatalytic approach for the oxidative self-dimerization of 2-naphthols using a semiconductor–metal hybrid that consists of intercalated manganese dioxide nanoparticles in reduced graphene oxide (rGO/MnO2) under visible-light irradiation. The desired photocatalyst was synthesized in a single step by mixing MnO2 nanoparticles with rGO ultrasonically. The hybrid photocatalyst exhibited a significantly higher activity than neat MnO2 nanoparticles and rGO, which is believed to be because of the synergistic effect of its components. To our knowledge, this hybrid rGO/MnO2 nanocomposite is the first heterogeneous, green photocatalyst for the oxidative coupling of 2-naphthols under mild conditions.
Selective, Catalytic, and Metal-Free Coupling of Electron-Rich Phenols and Anilides Using Molecular Oxygen as Terminal Oxidant
Bering, Luis,Vogt, Melina,Paulussen, Felix M.,Antonchick, Andrey P.
supporting information, p. 4077 - 4080 (2018/07/15)
Selective oxidative homo- and cross-coupling of electron-rich phenols and anilides was developed using nitrosonium tetrafluoroborate as a catalyst. Oxidative coupling of phenols revealed unusual selectivities, which translated into the unprecedented synthesis of inverse Pummerer-type ketones. Mechanistic studies suggest that oxidative coupling of phenols and anilides shares a common pathway via homolytical heteroatom-hydrogen bond cleavage. Nitrosonium salt catalysis was applied for cross-dehydrogenative coupling initiated by generation of heteroatom-centered radicals.
Synthetic Transformations Using Molecular Oxygen-Doped Carbon Materials
Periasamy, Mariappan,Shanmugaraja, Masilamani,Reddy, Polimera Obula,Ramusagar, Modala,Ananda Rao, Gunda
, p. 4944 - 4948 (2017/05/12)
Carbon materials like activated carbon (AC) undergo chemisorption with O2 to give species with electron deficiency in the carbon skeleton and negative charge at the oxygen end that upon reaction with PPh3 and benzoic acid afford Phs
In-depth structure-selectivity investigations on asymmetric, copper-catalyzed oxidative biaryl coupling in the presence of 5-cis-substituted prolinamines
Prause, Felix,Arensmeyer, Benjamin,Fr?hlich, Benjamin,Breuning, Matthias
, p. 2215 - 2226 (2015/04/14)
Thirteen new and 25 known prolinamines carrying an additional 5-cis substituent were evaluated as the chiral ligands in asymmetric copper-catalyzed, oxidative biaryl coupling of 3-hydroxy-2-naphthoates. Comprehensive structure-selectivity investigations r
