- Two-photon uncaging of bioactive thiols in live cells at wavelengths above 800 nm
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Photoactivatable protecting groups (PPGs) are useful for a broad range of applications ranging from biology to materials science. In chemical biology, induction of biological processesviaphotoactivation is a powerful strategy for achieving spatiotemporal control. The importance of cysteine, glutathione, and other bioactive thiols in regulating protein structure/activity and cell redox homeostasis makes modulation of thiol activity particularly useful. One major objective for enhancing the utility of photoactivatable protecting groups (PPGs) in living systems is creating PPGs with longer wavelength absorption maxima and efficient two-photon (TP) absorption. Toward these objectives, we developed a carboxyl- and dimethylamine-functionalized nitrodibenzofuran PPG scaffold (cDMA-NDBF) for thiol photoactivation, which has a bathochromic shift in the one-photon absorption maximum fromλmax= 315 nm with the unfunctionalized NDBF scaffold toλmax= 445 nm. While cDMA-NDBF-protected thiols are stable in the presence of UV irradiation, they undergo efficient broad-spectrum TP photolysis at wavelengths as long as 900 nm. To demonstrate the wavelength orthogonality of cDMA-NDBF and NDBF photolysis in a biological setting, caged farnesyltransferase enzyme inhibitors (FTI) were prepared and selectively photoactivated in live cells using 850-900 nm TP light for cDMA-NDBF-FTI and 300 nm UV light for NDBF-FTI. These experiments represent the first demonstration of thiol photoactivation at wavelengths above 800 nm. Consequently, cDMA-NDBF-caged thiols should have broad applicability in a wide range of experiments in chemical biology and materials science.
- Hammers, Matthew D.,Hodny, Michael H.,Bader, Taysir K.,Mahmoodi, M. Mohsen,Fang, Sifei,Fenton, Alexander D.,Nurie, Kadiro,Trial, Hallie O.,Xu, Feng,Healy, Andrew T.,Ball, Zachary T.,Blank, David A.,Distefano, Mark D.
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Read Online
- Nitrodibenzofuran: A One-and Two-Photon Sensitive Protecting Group That Is Superior to Brominated Hydroxycoumarin for Thiol Caging in Peptides
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Photoremovable protecting groups are important for a wide range of applications in peptide chemistry. Using Fmoc-Cys(Bhc-MOM)-OH, peptides containing a Bhc-protected cysteine residue can be easily prepared. However, such protected thiols can undergo isomerization to a dead-end product (a 4-methylcoumarin-3-yl thioether) upon photolysis. To circumvent that photoisomerization problem, we explored the use of nitrodibenzofuran (NDBF) for thiol protection by preparing cysteine-containing peptides where the thiol is masked with an NDBF group. This was accomplished by synthesizing Fmoc-Cys(NDBF)-OH and incorporating that residue into peptides by standard solid-phase peptide synthesis procedures. Irradiation with 365 nm light or two-photon excitation with 800 nm light resulted in efficient deprotection. To probe biological utility, thiol group uncaging was carried out using a peptide derived from the protein K-Ras4B to yield a sequence that is a known substrate for protein farnesyltransferase; irradiation of the NDBF-caged peptide in the presence of the enzyme resulted in the formation of the farnesylated product. Additionally, incubation of human ovarian carcinoma (SKOV3) cells with an NDBF-caged version of a farnesylated peptide followed by UV irradiation resulted in migration of the peptide from the cytosol/Golgi to the plasma membrane due to enzymatic palmitoylation. Overall, the high cleavage efficiency devoid of side reactions and significant two-photon cross-section of NDBF render it superior to Bhc for thiol group caging. This protecting group should be useful for a plethora of applications ranging from the development of light-Activatable cysteine-containing peptides to the development of light-sensitive biomaterials.
- Mahmoodi, M. Mohsen,Abate-Pella, Daniel,Pundsack, Tom J.,Palsuledesai, Charuta C.,Goff, Philip C.,Blank, David A.,Distefano, Mark D.
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Read Online
- One pot synthesis of diarylfurans from aryl esters and PhI(OAc)2 via palladium-associated iodonium ylides
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The example of palladium-catalyzed intermolecular cyclization for the synthesis of various diarylfurans in which one of the aromatic rings originates from the phenolic part of the starting ester and the other one from PhI(OAc)2 has been reported. The reaction is carried out through two steps: the rearrangement of palladium-associated iodonium ylides to form o-iodo diaryl ether and then palladium catalyzed intramolecular direct arylation. This reaction can tolerate a variety of functional groups and is alternative or complementary to the previous methods for the synthesis of diarylfurans.
- Bao, Yong-Sheng,Bao, Agula,Bao, Zhaorigetu,Jia, Meilin,Baiyin, Menghe
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Read Online
- Improved synthesis of a Smad3 phosphorylation inhibitor lingzhifuran A via condensation reaction
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A facile and high-efficient synthesis of lingzhifuran A, a Smad3 phosphorylation inhibitor isolated from Ganoderma lucidum, was developed from commercially available dibenzo[b,d]furan. The crucial step of this strategy was achieved via condensation reaction using key intermediate 8-hydroxydibenzo[b,d]furan-4-carbaldehyde and commercially available (E)-2-methylbut-2-enal. By this strategy, lingzhifuran A was obtained in 5 steps with up to 57.6% yield.
- Chen, Weiming,Xu, Xiaoling,Sun, Mingfeng,Huang, Xuelong,Ma, Weiping,Jiang, Feng
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p. 122 - 128
(2021/02/12)
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- Iron-Catalyzed Oxidative C?C Cross-Coupling Reaction of Tertiary Anilines with Hydroxyarenes by Using Air as Sole Oxidant
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A mild procedure for the oxidative C?C cross-coupling of tertiary anilines with phenols is described which provides the products generally in high yields and with excellent selectivity. The reaction is catalyzed by the hexadecafluorinated iron–phthalocyanine complex FePcF16 in the presence of substoichiometric amounts of methanesulfonic acid and ambient air as sole oxidant.
- Purtsas, Alexander,Kataeva, Olga,Kn?lker, Hans-Joachim
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p. 2499 - 2508
(2020/02/11)
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- Pyrazoles: 'one-pot' synthesis from arenes and carboxylic acids
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A rapid and efficient method for 'one-pot' synthesis of pyrazoles from (hetero)arenes and carboxylic acids via successive formation of ketones and β-diketones followed by heterocyclization with hydrazine has been developed. The utility of the RCOOH/TfOH/TFAA acylation system for intermediate production of ketones and 1,3-diketones is a key feature of this approach. The preliminary evaluation of the anticancer activity of the synthesized pyrazoles is performed.
- Gong, Ming,Kim, Jung Keun,Kovalev, Vladimir V.,Kovaleva, Olga V.,Shokova, Elvira A.,Tafeenko, Viktor A.,Wu, Yangjie
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supporting information
p. 5625 - 5638
(2020/08/21)
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- "one-Pot" Synthesis of γ-Pyrones from Aromatic Ketones/Heteroarenes and Carboxylic Acids
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Despite the various attractive properties of γ-pyrones, there are still some deficiencies in their synthetic approaches such as lower atom economy, multistep processes, and prefunctionalization of the reagents. In this work, an efficient and simple (CF3CO
- Sun, Xiangyu,Gong, Ming,Huang, Mengmeng,Li, Yabo,Kim, Jung Keun,Kovalev, Vladimir,Shokova, Elvira,Wu, Yangjie
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p. 15051 - 15061
(2020/12/02)
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- Base-Mediated Meerwein-Ponndorf-Verley Reduction of Aromatic and Heterocyclic Ketones
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An experimental protocol to achieve the Meerwein-Ponndorf-Verley (MPV) reduction of ketones under mildly basic conditions is reported. The transformation is tolerant of a range of ketone substrates, including O- and S-containing heterocycles, is scalable, and shows potential to be used as a platform to access enantioenriched products. These studies provide a general method for achieving the reduction of ketones under mildly basic conditions and offer an alternative protocol to more well-known Al-based MPV reduction conditions.
- Boit, Timothy B.,Mehta, Milauni M.,Garg, Neil K.
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supporting information
p. 6447 - 6451
(2019/08/20)
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- Fused imidazole compounds with indoleamine 2,3-dioxygenase inhibition activity
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The invention relates to fused imidazole compounds, and a preparation method and application thereof. The structure of the compounds is shown in a general formula I, wherein the definitions of each group are as described in the specification. The compounds are capable of selectively inhibiting indoleamine 2,3-dioxygenase (IDO). The compounds provided by the invention can be used as IDO inhibitorsfor the treatment and/or prevention of diseases with the pathological characteristics of IDO mediated tryptophan metabolism pathways, such as cancer, eye diseases, autoimmune diseases, psychological disorders, depression, anxiety and other diseases.
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Paragraph 0405-0408
(2018/07/10)
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- Visible-Light-Promoted Synthesis of Dibenzofuran Derivatives
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Dibenzofurans are naturally occurring molecules that have received considerable attention for a variety of practical applications, such as in pharmaceuticals and electronic materials. Herein, an efficient and eco-friendly method for the synthesis of dibenzofuran derivatives via intramolecular C-O bond formation, which involves the in situ production of a diazonium salt, is described. The transformation requires a diazotizing agent and is promoted by the use of an organic photosensitizer under visible-light irradiation.
- Cho, Ji Young,Roh, Geum-Bee,Cho, Eun Jin
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p. 805 - 811
(2018/01/28)
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- One-Pot Assembly of Fused Heterocycles via Oxidative Palladium-Catalyzed Cyclization of Arylols and Iodoarenes
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A one-pot, two-step cyclization reaction of iodoarenes with diversified arylols, including 4-hydroxyquinoline, quinolinone, 4-hydroxypyridine and phenol, has been developed. By using this palladium-catalyzed formal tandem O-arylation, dehydrogenative cross-coupling reaction, a variety of biologically significant fused benzo[4,5]furo heterocycles and dibenzofurans were quickly assembled in high yields with excellent regioselectivity. Notably, the efficient one-pot reaction led to the heterocycles via sequential oxidation, iodination, isomerization and cyclization steps without purification of any reaction intermediates.
- Hong, Fenglin,Chen, Yingwen,Lu, Beili,Cheng, Jiajia
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p. 353 - 357
(2016/02/12)
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- Catalysis of the acylation of aromatic derivatives by metallic tosylates
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A series of metallic tosylates were prepared by ultrasonic metal activation and were further used as efficient catalysts for the acylation of aromatic derivatives.
- Morizur, Vincent,Szafranek, Jessica,Bonhomme, Dominique,Olivero, Sandra,Desmurs, Jean Roger,Du?ach, Elisabet
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supporting information
p. 6813 - 6817
(2015/08/24)
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- Synthesis of Dibenzofurans via C-H Activation of o-Iodo Diaryl Ethers
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An efficient method for the synthesis of dibenzofuran from o-iododiaryl ether using reusable Pd/C under ligand-free conditions has been developed. Synthesis of o-iododiaryl ether was achieved in one pot through sequential iodination and O-arylation of phenol under mild reaction conditions.
- Panda, Niranjan,Mattan, Irshad,Nayak, Dinesh Kumar
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p. 6590 - 6597
(2015/10/06)
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- Iron-catalyzed aryl-aryl cross coupling route for the synthesis of 1-(2-amino)-phenyl)dibenzo[b,d]furan-2-ol derivatives and their biological evaluation
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Naturally occurring dibenzofuran motifs represent promising lead structures for the development of novel antimycobacterial agents. Prompted by our recent development of cross dehydrogenative coupling using iron catalysis, we extended our strategy to synthesize 14 novel anilinodibenzofuranols and they were explored for anti-tubercular and cytotoxic activities. Consistent with our hypothesis, DBF-3, 14 and 16 exhibited promising activity against two strains (M. tuberculosis H37Rv and the clinical S, H, R, and E resistant isolate), while DBF-13, 18 exhibited selective inhibitory activity only against the clinical S, H, R and E resistant isolate. However, the compounds DBF-4 and DBF-8 showed promising and selective antitumor activity against the tested cancer cell lines. The Royal Society of Chemistry 2013.
- Chiranjeevi, Barreddi,Koyyada, Ganesh,Prabusreenivasan,Kumar, Vanaja,Sujitha, Pombala,Kumar, C. Ganesh,Sridhar,Shaik, Saida,Chandrasekharam, Malapaka
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p. 16475 - 16485
(2013/09/23)
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- Synthesis and antitumor activities of novel dibenzo[b,d]furan-imidazole hybrid compounds
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A series of novel hybrid compounds between dibenzo[b,d]furan and imidazole has been prepared and evaluated in vitro against a panel of human tumor cell lines. The results suggest that the existence of benzimidazole ring, and the substitution of the imidaz
- Liu, Lan-Xiang,Wang, Xue-Quan,Yan, Ju-Ming,Li, Yan,Sun, Cheng-Jun,Chen, Wen,Zhou, Bei,Zhang, Hong-Bin,Yang, Xiao-Dong
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supporting information
p. 423 - 437
(2013/10/01)
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- Design, synthesis, and structure-activity correlations of novel dibenzo[b,d furan, dibenzo[b,d]thiophene, and N-methylcarbazole clubbed 1,2,3-triazoles as potent inhibitors of mycobacterium tuberculosis
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A molecular hybridization approach is an emerging structural modification tool to design new molecules with improved pharmacophoric properties. In this study, 1,2,3-triazole-based Mycobacterium tuberculosis inhibitors and synthetic and natural product-bas
- Patpi, Santhosh Reddy,Pulipati, Lokesh,Yogeeswari, Perumal,Sriram, Dharmarajan,Jain, Nishant,Sridhar, Balasubramanian,Murthy, Ramalinga,Anjana Devi,Kalivendi, Shasi Vardhan,Kantevari, Srinivas
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experimental part
p. 3911 - 3922
(2012/07/14)
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- Synthesis and antitubercular evaluation of amidoalkyl dibenzofuranols and 1H-benzo[2,3]benzofuro[4,5-e][1,3]oxazin-3(2H)-ones
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A new class of amidoalkyl dibenzofuranols and 1H-benzo[2,3]benzofuro[4,5-e] [1,3]oxazin-3(2H)-ones was synthesized in very good yields through polyphosphoric acid supported on silica (PPA-SiO2) catalyzed one-pot three component condensation of 2-dibenzofuranol; aromatic aldehydes and acetamide or benzamide or urea under solvent free conditions. At 125 °C the reaction led to the formation of amidoalkyl dibenzofuranols 5a-k where as at 160 °C cyclization take place to give oxazin-3(2H)-one analogues 6a-e. Screening all the 16 compounds for in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv (MTB) resulted 1-((4-chlorophenyl)(2- hydroxydibenzo[b,d]furanyl)methyl)urea 5h; 1-((4-bromophenyl)(2- hydroxydibenzo[b,d]furanyl)methyl)urea 5i; 1-phenyl-1H-benzo[2,3]benzo furo[4,5-e][1,3]oxazin-3(2H)-one 6a (MIC 3.13 μg/mL) and 1-(4-chlorophenyl)- 1H-benzo[2,3]benzofuro[4,5-e][1,3]oxazin-3(2H)-one 6b; 1-(4-bromophenyl)-1H- benzo[2,3]benzofuro [4,5-e][1,3]oxazin-3(2H)-one 6c (MIC 1.56 μg/mL) as most active antitubercular agents.
- Kantevari, Srinivas,Yempala, Thirumal,Yogeeswari, Perumal,Sriram, Dharmarajan,Sridhar, Balasubramanian
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supporting information; experimental part
p. 4316 - 4319
(2011/08/09)
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- Synthesis of dibenzofurans via palladium-catalyzed phenol-directed C-H activation/C-O cyclization
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A practical, Pd(0)/Pd(II)-catalyzed reaction was developed for phenol-directed C-H activation/C-O cyclization using air as an oxidant. The turnover-limiting step of the process was found to be C-O reductive elimination instead of C-H activation. This reaction can tolerate a variety of functional groups and is complementary to the previous methods for the synthesis of substituted dibenzofurans.
- Xiao, Bin,Gong, Tian-Jun,Liu, Zhao-Jing,Liu, Jing-Hui,Luo, Dong-Fen,Xu, Jun,Liu, Lei
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supporting information; experimental part
p. 9250 - 9253
(2011/08/06)
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- Synthesis of carbazoles and dibenzofurans via cross-coupling of o-iodoanilines and o-iodophenols with silylaryl triflates and subsequent Pd-catalyzed cyclization
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An efficient route to a variety of carbazoles and dibenzofurans has been developed. It involves the reaction of o-iodoanilines or o-iodophenols with silylaryl triflates in the presence of CsF to afford the N- or O-arylated products, which are subsequently cyclized using a Pd catalyst to carbazoles and dibenzofurans in good to excellent yields. By using this methodology, the carbazole alkaloid, mukonine has been synthesized in 76% overall yield in three steps.
- Liu, Zhijian,Larock, Richard C.
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p. 347 - 355
(2007/10/03)
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- SYNTHESIS OF NITRODIBENZYLFURAN CHROMOPHORE FOR PHOTODEPROTECTION OF ORGANIC MOLECULES
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Inventors have developed a chromophore (nitrodibenzylfuranyl, or NBDF) for ultra efficient uncaging of a caged substrate (e.g., an organic molecule such as, for example, an amino acid, a biological molecules, such as, for example, second messengers inside cells). Photolysis of a NBDF derivative of EGTA (i.e. caged calcium) is about 50 times more efficient than others calcium cages (the quantum yield of photolysis is 0.6 and the extinction coefficient is 18,400. NDBF-EGTA has a 2-photon cross section of about 0.3-0.6 GM).
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Page/Page column 27
(2008/06/13)
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- Inhibitors of protein farnesyltransferase and squalene synthase
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The present invention provides a compound of the formula STR1 or a pharmaceutically acceptable salt thereof, which are useful in inhibiting protein farnesyltransferase and the farnesylation of the oncogene protein Ras or inhibiting de novo squalene production resulting in the inhibition of cholesterol biosynthesis, processes for the preparation of the compounds of the invention in addition to intermediates useful in these processes, a pharmaceutical composition, and to methods of using such compounds.
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- Gas phase generation and cyclisation reactions of some o-substituted phenyl radicals
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Flash vacuum pyrolysis of the allyl esters 2 (X=O, S, CH2, CO) at 900°C (10-2 Torr) gives dibenzofurans, dibenzothiophenes, fluorenes, and fluorenones respectively as the major products. The mechanism involves the phenyl radical intermediates 1 which equilibrate by intramolecular hydrogen transfer via six-membered transition states, prior to cyclisation.
- Cadogan,Hutchison,McNab
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p. 7747 - 7762
(2007/10/02)
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- A Remarkable Difference of the Positional Selectivity in Electrophilic Aromatic Substitution of Dibenzofuran between the Classical ?-Complex and Charge-Transfer Mechanisms
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Electrophilic nitration of dibenzofuran with nitric acid by a charge-transfer mechanism occurs exclusively at the 3-position and on the other hand, substitution at the 2-position predominates in the acylation, in which a classical ?-complex mechanism is important.
- Keumi, Takashi,Hamanaka, Kozo,Hasegawa, Haruo,Minamide, Naoki,Inoue, Yoshinori,Kitajima, Hidehiko
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p. 1285 - 1288
(2007/10/02)
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- Carbonylation of Aryl Halides and Vinyl Bromides Mediated by Tetracarbonylcobalt Anion
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The reaction of aryl halides (1a-g) with octacarbonyldicobalt in the presence of methyl iodide and sodium hydroxide under phase-transfer conditions was found to give a mixture of aryl methyl ketones (2a-g) and aromatic carboxylic acids (3a-h).From vinyl halides (9a-c), however, the corresponding carboxylic acids (10a-c) were obtained exclusively.
- Miura, Masahiro,Akase, Fumiaki,Shinohara, Masato,Nomura, Masakatsu
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p. 1021 - 1026
(2007/10/02)
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