- Molecular tweezers: Synthesis and formation of host-guest complexes
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A chiral molecular tweezer obtained from (+)-usnic acid placed in solution in the presence of various aromatic compounds afforded complexes with low association constants. Thus, the X-ray structure of assembly 31 is presented, where the guest is sandwiched between the two pincers of the tweezer. The association constants for various guests were determined through different methods. Finally, other tweezers with electron-rich aromatic aldehydes and ketones were prepared from (1R,2R)-1,2-diaminocyclohexane. The most interesting complexes were also confirmed through structural analysis, and the best results were obtained with 10-hydroxyphenanthrene-9-carbaldehyde (51) as the aromatic moiety.
- Legouin, Beatrice,Gayral, Maud,Uriac, Philippe,Cupif, Jean-Francois,Levoin, Nicolas,Toupet, Loic,Van De Weghe, Pierre
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Read Online
- A Two-Photon H2O2-Activated CO Photoreleaser
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Carbon monoxide (CO) is proposed as an active pharmaceutical agent with promising pharmaceutical prospects, as it has been involved in multifaceted modulation of diverse physiological and pathological processes. However, questions remain for therapeutic a
- Li, Yong,Shu, Yingzheng,Liang, Muwen,Xie, Xilei,Jiao, Xiaoyun,Wang, Xu,Tang, Bo
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Read Online
- Convenient Syntheses of Naturally Occurring Angular and Linear Naphthopvrans
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A convenient synthesis of naturally occurring angular naphthopyrans and their 6-demethoxy derivatives is described starting from 2-acetyl-1-naphthols along with the synthesis of linear naphthopyrans from 3-acetyl-2-naphthol.
- Paradkar, Madhusudan V.,Godbole, Himanshu M.,Ranade, Anup A.,Joseph, Augustine R.
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Read Online
- TRICYCLIC COMPOUNDS ACTING ON CRBN PROTEINS
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The present invention discloses a series of tricyclic compounds and use thereof in preparing a medicament for treating a disease related to CRBN protein. Specifically, the present invention discloses a derivative compound of formula (1) or a pharmaceutically acceptable salt thereof.
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Paragraph 0108; 0111
(2021/07/17)
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- Solvatofluorochromic flavonoid dyes with enlarged transition dipole moments enable the ratiometric detection of methanol in commercial biodiesel with improved sensitivities
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Detection of methanol in commercial biodiesel is essential to evaluate the fuel quality associated with the matter of driving safety. Compared to the standard GC method, the fluorescent detection method for methanol is much simpler and faster, but still u
- Du, Bing,Huang, Yingying,Liu, Bin,Qin, Tianyi,Xu, Hanhong,Xun, Zhiqing,Yao, Guangkai,Zhao, Chen
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p. 16808 - 16814
(2020/12/30)
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- Nucleophilic addition reaction with dearomatization of naphthalene ring
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Various aromatic lactones have been synthesized and their regioselectivity (1,2-addition vs. 1,4- or 1,6-addition) investigated in reactions with organolithium species, particularly n-BuLi and sec-BuLi. The regioselectivity varied greatly depending on various factors, such as the bulkiness of both substrates and organolithium species, and types of solvent and cosolvent. In particular, 1,4-addition with dearomatization occurred preferentially using sec-BuLi as the nucleophile in tetrahydrofuran (THF) with hexamethylphosphoramide (HMPA) or N,N′-dimethylpropyleneurea (DMPU) as cosolvent. For sec-BuLi, the reaction was estimated to proceed through a single-electron transfer mechanism.
- Imayoshi, Ayumi,Kiyotaki, Kotaro,Sasaki, Hirotaka,Tsubaki, Kazunori
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p. 384 - 391
(2020/05/14)
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- Synthesis of Polysubstituted 2-Naphthols by Palladium-Catalyzed Intramolecular Arylation/Aromatization Cascade
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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.).
- Cai, Jinhui,Hu, Xu-Dong,Liu, Wen-Bo,Wang, Zhen-Kai,Yao, Fei,Zhang, Yun-Hao
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supporting information
(2020/02/25)
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- De Novo Synthesis of Phenols and Naphthols through Oxidative Cycloaromatization of Dienynes
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In this work, a rhodium-catalyzed oxidative cycloaromatization of dienynes, which provides a highly straightforward and efficient way to access polysubstituted naphthols and phenols under mild conditions, is described. Challenged electron-withdrawing groups are well tolerated in this protocol, and late-stage phenyl ring formation is demonstrated.
- Rong, Ming-Guang,Qin, Tian-Zhu,Liu, Xin-Rui,Wang, Hong-Fa,Zi, Weiwei
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supporting information
p. 6289 - 6293
(2018/10/09)
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- Carbon Monoxide Releasing Molecules and Associated Methods
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The present disclosure relates to carbon monoxide releasing molecules (“CORMs”), and methods of synthesizing and applying the molecules. More specifically, this disclosure relates to structurally tunable CORMS, compounds containing CORMS (and salts thereof). An exemplary compound includes:
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Paragraph 0080
(2016/08/17)
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- Highly chemoselective and versatile method for direct conversion of carboxylic acids to ketones utilizing zinc Ate complexes
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Various carboxylic acids were directly transformed into the corresponding ketones by utilizing organozinc ate complexes, which provide high chemoselectivity without any overreaction to the undesired tertiary carbinol, owing to formation of a stable tetrahedral zincioketal intermediate. This method offers good overall atom/step/pot economy and operational simplicity. No need to overreact: Various carboxylic acids were directly transformed to the corresponding ketones by utilizing organozinc ate complexes, which provide high chemoselectivity without any overreaction to undesired tertiary carbinol, owing to formation of a stable tetrahedral zincioketal intermediate. This method offers good overall atom/step/pot economy and operational simplicity.
- Murata, Ryo,Hirano, Keiichi,Uchiyama, Masanobu
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supporting information
p. 1286 - 1290
(2015/06/08)
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- Lithiation of a silyl ether: Formation of an ortho-fries hydroxyketone
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A hydroxy-directed alkylation of an N,N-diethylarylamide using CIPE-assisted α-silyl carbanions (CIPE=complex-induced proximity effect) has been developed using a simple reagent combination of LDA (lithium diisopropylamide) and chlorosilane. A study of the mechanism, and the application of the procedure to an anionic Snieckus-Fries rearrangement for a highly efficient synthesis of the potent phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002, are reported.
- Lo, Hong-Jay,Lin, Chin-Yin,Tseng, Mei-Chun,Chein, Rong-Jie
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p. 9026 - 9029
(2014/09/17)
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- Comparisons of O-acylation and Friedel-Crafts acylation of phenols and acyl chlorides and Fries rearrangement of phenyl esters in trifluoromethanesulfonic acid: Effective synthesis of optically active homotyrosines
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Reactions involving phenol derivatives and acyl chlorides have to be controlled for competitive O-acylations and C-acylations (Friedel-Crafts acylations and Fries rearrangements) in acidic condition. The extent for these reactions in trifluoromethanesulfonic acid (TfOH), which is used as catalyst and solvent, is examined. Although diluted TfOH was needed for effective O-acylation, concentrated TfOH was required for effective C-acylations in mild condition. These results have been applied to the novel synthesis of homotyrosine derivatives. Both Fries rearrangement of N-TFA-Asp(OBn)-OMe and Friedel-Crafts acylation of phenol with N-TFA-Asp(Cl)-OMe in TfOH afforded the homotyrosine skeleton, followed by reduction and deprotection afforded homotyrosines maintaining stereochemistry of Asp as an optically pure form.
- Murashige, Ryo,Hayashi, Yuka,Ohmori, Syo,Torii, Ayuko,Aizu, Yoko,Muto, Yasuyuki,Murai, Yuta,Oda, Yuji,Hashimoto, Makoto
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experimental part
p. 641 - 649
(2011/03/19)
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- Enantioselective oxidative biaryl coupling reactions catalyzed by 1,5-diazadecalin metal complexes: Efficient formation of chiral functionalized BINOL derivatives
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Chiral 1,5-diaza-cis-decalins have been examined as ligands in the enantioselective oxidative biaryl coupling of substituted 2-naphthol derivatives. Under the optimal conditions employing 2.5-10 mol % of a 1,5-diaza-cis-decalin copper(II) catalyst with oxygen as the oxidant, enantioselective couplings (44-96% ee) could be achieved for a range of 3-substituted 2-naphthols including the ester, ketone, phosphonyl, and sulfonyl derivatives. The relationship between the substitution of the naphthalene starting materials and reactivity/selectivity is determined by several factors which act in concert: (1) the effect of substituents on the oxidation potential of the substrate, (2) the ability of the substrate to participate in a chelated copper complex which depends on (a) the inherent coordinating ability of the 3-substituent and (b) substituent steric interactions that affect chelation between the 2-hydroxyl and 3-substituent, (3) the effect of substituents on dissociation of the product from the copper catalyst.
- Li, Xiaolin,Hewgley, J. Brian,Mulrooney, Carol A.,Yang, Jaemoon,Kozlowski, Marisa C.
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p. 5500 - 5511
(2007/10/03)
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- Effect of cyclodextrin complexation on photo-fries rearrangement of naphthyl esters
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Photolysis of β-cyclodextrin inclusion complexes of 1- and 2-naphthyl esters (acetates and benzoates) in aqueous medium, results in rearrangement to give one isomer of acylnaphthol in excess, whereas the solid state irradiation of the cyclodextrin complexes yields selectively one isomer. In addition, formation of cleavage product is totally suppressed. This remarkable selectivity is attributed to specific modes of the complexation of the esters into the β-CD cavity.
- Banu, Habeeb Shayira,Pitchumani, Kasi,Srinivasan, Chockalingam
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p. 9601 - 9610
(2007/10/03)
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- Investigation of the photo-fries rearrangements of two 2-naphthyl alkanoates by experiment and theory. Comparison with the acid-catalyzed reactions
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A detailed investigation of the photochemistry of 2-naphthyl acetate (1a) and 2-naphthyl myristate (1b) has been conducted under a variety of conditions. Factors related to the reactions such as temperature and solvent type have been explored. The results, most easily interpreted by photo-Fries type processes, are contrasted with those from the Lewis-acid catalyzed (dark) Fries reactions of 1a. They are also compared to the predictions of semiempirical and ab initio calculations using 2-naphthyl propanoate (1c) and species derived from it as models. Unsuccessful triplet sensitization experiments with benzophenone and calculations point to the excited singlet states of 1 as the immediate precursor to the acyl/2-naphthoxy radical pairs that recombine to form keto intermediates 2, reform 1, or diffuse apart and eventually yield 2-naphthol (4); enolization of 2 results in the isolated rearrangement products, n-acyl-2-naphthols (n-3). Static and dynamic fluorescence studies provide some insights into the nature of the lysis process. Irradiation of a mixture of appropriately labeled derivatives of 1 led to none of the expected "cross-over" products, indicating that the intermediates 2 arise from recombination of radical pairs from the same parent molecule. Irradiation of 1b in ethanol and 1-octanol provides no evidence for the intermediacy of dodecylketene and supports out-of-cage mechanisms as the exclusive source of 4. There are indications of subtle solvent effects and a conformational dependence on the distribution of photoproducts.
- Cui, Changxing,Wang, Xiaochun,Weiss, Richard G.
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p. 1962 - 1974
(2007/10/03)
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- Photo-Fries reaction of naphthyl esters within zeolites
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Photolysis of naphthyl esters within zeolites leads to the photo-Fries rearrangements as in isotropic solution. However, a high level of product selectivity is obtained using 'cation as the key'. A key component for predicting the selectivity of photoreactions within zeolites, namely the location of reactants, is missing at this stage.
- Pitchumani,Warrier,Cui,Weiss,Ramamurthy
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p. 6251 - 6254
(2007/10/03)
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- The Reaction of Ethyl Chromone-2-carboxylates with 1,2-Diaminobenzene
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Ethyl chromone-2-carboxylate and all its benzoanalogs were prepared and caused to react with 1,2-diaminobenzene to give 2-(2-hydroxybenzoyl)methinyl-3-oxo-1,2,3,4-tetrahydroquinoxaline and its benzo analogs.The condensation products of diethyl oxalate and
- Markees, Diether G.
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- Cycloadditions of substituted benzopyran-4-ones to electron-rich dienes: a new route to xanthone derivatives
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The benzopyranones 1 and 3 reacted with 2,3-dimethyl-1,3-butadiene in the presence of titanium (IV) chloride to give the corresponding (4 + 2) cycloadducts 8 and 11, the former undergoing facile deformylation to give 9 and 10. Compounds 1, 3, and 4 underwent efficient uncatalysed cycloaddition to 1- methoxy-3-(trimethylsilyloxy)-l,3-butadiene 12 to give the respective adducts 13,14, and 18 as mixtures of C-l stereoisomers. Heating the 3-arylsulphinylchromone 5 with the diene 12 afforded 3-hydroxyxanthone 23 in 50% yield, the presumed cycloaddition - elimination sequence constituting a new route to xanthone systems. Desilylation of 13,14, and 18 in acidic media provided 25,26, and 27 respectively.
- Cremins, Peter J.,Saengchantara, Suthiweth T.,Wallace, Timothy W.
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p. 3075 - 3082
(2007/10/02)
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- Research on nitro-derivatives of biological interest. XXX Methylated 2-nitronaphthofuranes, synthesis and activity against microorganisms
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2-Nitrofuran derivatives methylated on their heterocycle must be prepared after various methods, according to cases. 1-Methyl 2-nitro naphtho [2. 1-b]furan is formed - with a yield of about 35% - by displacing the keton group of 2-acetyl of 2-acetyl 1-methyl naphtho [2. 1-b]furan using nitric acid in acetic acid. 7-Methoxy 1-methyl 2-nitro naphtho [2. 1-b]furan is obtained by treating 7-methoxy 1-methyl naphtho [2. 1-b]furan with a limited quantity of nitric acid in methylene chloride. Yield near to 10%. 3-Methyl 2-nitro naphtho [2. 3-b]furan is only accessible by deshydrogenation of 3-methyl 2-nitro 5.6.7.8-tetrahydro naphtho [2. 3-b]furan - which synthesis was previously described. Finally, 3-methyl 2-nitro naphtho [1. 2-b]furan is elaborated by action of nitric acid in methylene choride on 2-acetyl 3-methyl naphtho [1. 2-b]furan. Approximate yield: 25%. The methyl group added to the 2-nitro-naphthofuran heterocycle enhances the antibacterial and protozoocidal activities when one passes from 2-nitro naphtho [2. 1-b]furan to 1-methyl 2-nitro naphtho [2.1-b]furan. Nevertheless, it strongly decreases the antibacterial activity when one passes from 7-methoxy 2-nitro naphtho [2. 1-b]furan to 7-methoxy 1-methyl 2-nitro naphtho [2. 1-b]furan. The modifications in the activities noticed in the other cases are of less importance.
- Einhorn,Demerseman,Royer,Cavier
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p. 175 - 180
(2007/10/02)
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