- Design and chemical synthesis of root gravitropism inhibitors: Bridged analogues of ku-76 have more potent activity
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Previously, we found (2Z,4E)-5-phenylpenta-2,4-dienoic acid (ku-76) to be a selective inhibitor of root gravitropic bending of lettuce radicles at 5 μM, with no concomitant growth inhibition, and revealed the structure–activity relationship in this inhibitory activity. The conformation of ku-76 is flexible owing to the open-chain structure of pentan-2,4-dienoic acid with freely rotating single bonds, and the (2Z)-alkene moiety may be isomerized by external factors. To develop more potent inhibitors and obtain insight into the target biomolecules, various analogues of ku-76, fixed through conformation and/or configuration, were synthesized and evaluated. Stereochemical fixation was effective in improving the potency of gravitropic bending inhibition. Finally, we found highly potent conformational and/or configurational analogues (ku-257, ku-294 and ku-308), that did not inhibit root growth. The inhibition of root curvature by these analogues was comparable to that of naptalam.
- Fujii, Yoshiharu,Iwata, Takayuki,Kano, Arihiro,Kodama, Kozue,Makigawa, Saki,Matsumoto, Kenji,Morita, Miyo Terao,Shindo, Mitsuru,Sugiyama, Hiromi,Wasano, Naoya
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- Axially Chiral 1,1'-Binaphthyl-2-Carboxylic Acid (BINA-Cox) as Ligands for Titanium-Catalyzed Asymmetric Hydroalkoxylation
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Axially chiral, enantiopure 1,1'-binaphthyl-2-carboxylic acids (BINA-Cox) have recently been introduced as chiral ligands for transition metal catalysis. Together with equimolar, co-catalytic amounts of Ti(OiPr)4 and water they form an in situ catalyst that performs the asymmetric catalytic hydroalkoxylation of 2-allylphenols to 2-methylcoumarans at high temperature (240 °C, microwave heating). The synthesis of reference ligand 2'-MeO-BINA-Cox (L1) has been optimized and performed at molar scale. Synthetic routes have been developed to access a variety of substituted BINA-Cox ligands (>30 examples), which have been tested for ligand effects on the reference asymmetric cyclization of 2-allylphenol. The substrate range of asymmetric catalytic hydroalkoxylation has been explored through systematic substrate structure variations to define scope and limitations of the titanium-catalyzed process. The new substrates 2-(1-vinylcycloalkyl)phenols (1j, 1k), 2-(2-vinylphenyl)propan-2-ol (1t), and 2'-vinyl-[1,1'-biphenyl]-2-ol (1u) are shown to undergo asymmetric catalytic cyclization to benzodihydrofurans and benzo[c]chromene, respectively.
- Blazejak, Max,Helmbrecht, Sebastian L.,Hintermann, Lukas,Schlüter, Johannes
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supporting information
(2020/04/15)
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- Synthesis, modeling studies and evaluation of E-stilbene hydrazides as potent anticancer agents
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A group of new thermodynamically more stable E-2-styrylbenzohydrazide derivatives (5a-i) were synthesized via palladium catalyzed Mizoroki-Heck reaction conditions. All synthesized compounds were characterized by UV-visible, FT-IR, 1H NMR, sup
- Iqbal, Ahsan,Khan, Zulfiqar Ali,Shahzad, Sohail Anjum,Ahmad Khan, Shakeel,Raza Naqvi, Syed Ali,Bari, Ayesha,Amjad, Hira,Umar, Muhammad Ihtisham
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p. 271 - 281
(2019/07/31)
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- Nickel-catalyzed reductive defunctionalization of esters in the absence of an external reductant: Activation of C-O bonds
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The nickel-catalyzed reductive cleavage of esters in the absence of an external reductant, which involves the cleavage of an inert acyl C-O bond in O-Alkyl esters is reported. Various groups, such as N-containing heterocycles, esters, amides, and even arene rings can function as a directing group.
- Iyori, Yasuaki,Takahashi, Kenjiro,Yamazaki, Ken,Ano, Yusuke,Chatani, Naoto
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supporting information
p. 13610 - 13613
(2019/11/14)
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- Synthesis of E-stilbene azomethines as potent antimicrobial and antioxidant agents
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A series of new extensively conjugated E -stilbene azomethines (5a–5h) were synthesized and screened for their antioxidant and antimicrobial activity. The compounds were tested against bacterial (Escherichia coli, Staphylococcus aureus, Klebsiella pneumon
- Iqbal, Ahsan,Khan, Zulfiqar Ali,Shahzad, Sohail Anjum,Usman, Muhammad,Khan, Shakeel Ahmad,Fauq, Abdul H.,Bari, Ayesha,Sajid, Muhammad Aamir
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p. 1518 - 1533
(2019/01/03)
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- Sunlight promoted palladium catalysed Mizoroki-Heck, Suzuki-Miyaura and Sonogashira reactions
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The palladium catalysed Mizoroki-Heck, Suzuki-Miyaura and Sonogashira reactions were successfully carried out under irradiation with sunlight. The Heck reaction gives considerable amount of Z product due to photochemical isomerization of initially formed E alkenes. Reaction of methyl 2-iodobenzoate with acrylamide under solar condition furnished 2H-2-benzazepine-1,3-dione rather than the expected derivative of cinnamate while the same reaction with ethyl 2-iodobenzoate gave the desired cinnamide.
- Chaudhary, Anju R.,Bedekar, Ashutosh V.
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p. 6100 - 6103,4
(2020/08/20)
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- Discovery of phenyl alanine derived ketoamides carrying benzoyl residues as novel calpain inhibitors
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Novel calpain inhibitors derived from phenyl alanine aldehydes or ketoamides carrying a benzoyl residue were prepared and evaluated for their biological potency. A brief structure-activity relationship elucidated the importance of ortho-substitutents in t
- Lubisch, Wilfried,Moeller
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p. 1335 - 1338
(2007/10/03)
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- Novel rhodium-catalyzed cyclic carbonylation of 2- phenylethynylbenzoates leading to indeno[1,2-c]isocoumarin
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Rhodium-catalyzed reaction of ethyl 2-phenylethynylbenzoate under watergas shift reaction conditions results in the formation of a tetracyclic lactone, indeno[1,2-c]isocoumarin, as a major product which is derived from bond fission of the ester group and
- Sugioka, Takashi,Yoneda, Eiji,Onitsuka, Kiyotaka,Zhang, Shi-Wei,Takahashi, Shigetoshi
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p. 4989 - 4992
(2007/10/03)
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