- Pyrrole-Based Anion-Responsive π-Electronic Molecules as Hydrogen-Bonding Catalysts
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The abilities of dipyrrolyldiketone boron complexes as hydrogen-bonding donor organocatalysts were examined by the Mannich-type reaction of N-acyl heteroarenium chlorides with 1-methoxy-2-methyl-1-trimethylsiloxy-1-propene, as well as by the classical N-alkylation of amines with trityl chloride under base-free conditions. 1H NMR examinations of the hydrogen-bonding interaction between the pyrrole NH of the catalyst and the Cl- in the N-acyl heteroarenium salt suggested that the activation of N-acyl heteroarenium chlorides occurs through anion binding by the catalyst.
- Hirata, Goki,Maeda, Hiromitsu
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- Photophysical studies and submicron ring formation of morpholino U-nucleoside monomers
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Synthesis, photophysical properties and submicron ring formation of functionalized uracil morpholino monomers have been reported. A series of characterization techniques indicated that the rings are formed by the inter-molecular hydrogen bonding of the uracil nucleus having a trityl-protected morpholino moiety. This is the smallest nucleoside unit known to date for submicron size ring formation.
- Paul, Sibasish,Jana, Santanu,Bhadra, Jhuma,Sinha, Surajit
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- Temporal control in tritylation reactions through light-driven variation in chloride ion binding catalysis-a proof of concept
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Tripodal triazole-linked azo(hetero)arene-based photoswitchable catalysts T1-5 have been designed, synthesized and optimized for the tritylation reaction of benzylamine (BzNH2). The tritylation reaction rates/yields achieved by light induced isomerization are compared between the native and photoswitched states of the catalyst T1. This concept of controlling the tritylation reaction rates with light has also been extended to additional substrates. The critical role of the triazole C-H?Cl- interactions has been confirmed by a combination of spectroscopic, calorimetric and computational studies. Also, the effect of variation in the binding affinities between the native and photoswitched states of the catalyst at room temperature in the temporal control of the catalysis has been demonstrated. This journal is
- Bari, Naimat K.,Grewal, Surbhi,Kumar, Himanshu,Roy, Saonli,Saraswat, Mayank,Sinha, Sharmistha,Venkataramani, Sugumar
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- Skin care
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PROBLEM TO BE SOLVED: To provide a skin care preparation suitable for preventing or ameliorating pigment deposition. SOLUTION: The skin care preparation comprises two compounds represented by general formula (1) [wherein R1is an aromatic group; R2is a hydrogen atom, alkyl or acyl; R3is a hydrogen atom or alkyl] and represented by general formula (2) [wherein R4is an aromatic group or hydrogen atom; R5and R6are each an aromatic group; R7and R8are mutually bonded to form a 2-8C nitrogen heterocyclic ring]. COPYRIGHT: (C)2013,JPOandINPIT
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Paragraph 0113-0114
(2020/10/19)
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- MELANIN PRODUCTION INHIBITOR
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Disclosed is a melanin production inhibitor which has an excellent inhibitory activity on the production of melanin and is highly safe. The melanin production inhibitor is represented by general formula (1) (excluding clotrimazole) and/or a pharmacologically acceptable salt thereof. In the formula, A1, A2 and A3 are independently selected from a hydrogen atom, an aryl group which may have a substituent, and an aromatic heterocyclic group which may have a substituent. At least one of A1, A2 and A3 is selected from the aryl group and the aromatic heterocyclic group, the total number of carbon atoms contained in A1, A2 and A3 is 6 to 50 and, when at least two of A1, A2 and A3 represent the aryl groups or the aromatic heterocyclic groups, the adjacent two aryl or aromatic heterocyclic groups may be bound to each other via an alkyl chain or an alkenyl chain to form a ring; m represents an integer of 0 to 2; X represents a hetero atom, a hydrogen atom, or a carbon atom; R1 and R2 are independently selected from a hydrogen atom and an oxo group. When one of R1 and R2 is an oxo group, the other is not present. R3 is selected from a hydrogen atom, and a C1-8 hydrocarbon group in which one or some of hydrogen atoms or carbon atoms may be substituted by a hetero atom or hetero atoms. The number of R3's present in the compound corresponds to X and, when two or more R3's are present, the R3's are independently present and the adjacent two R3's may be bound to each other to form, together with X, a ring, and the terminal of R3 may be bound to a carbon atom to which A1, A2 and A3 are bound, thereby forming a ring.
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Paragraph 0198 - 0202
(2015/12/17)
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- "Click" bis-triazoles as neutral C-H?anion-acceptor organocatalysts
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A new player on the field! "Click" bis-triazoles have been introduced as a highly efficient new class of neutral C-H?anion-binding organocatalysts (see scheme). DFT and NMR studies were used to confirm this activation modus and identify the optimal catalyst. Copyright
- Beckendorf, Stephan,Asmus, S?ren,Mück-Lichtenfeld, Christian,García Manche?o, Olga
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p. 1581 - 1585
(2013/03/14)
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- Design, synthesis and identification of a new class of triarylmethyl amine compounds as inhibitors of apolipoprotein e production
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We have identified a new class of triarylmethyl amine compounds that can inhibit apolipoprotein E (apoE) production. ApoE is a cholesterol- and lipid-carrier protein implicated in aging, atherosclerosis, Alzheimer's Disease (AD), and other neurological and lipid-related disorders. Attenuation of apoE production is generally considered to be of therapeutic value. A majority of the apoE in the brain is produced by astrocytes. Here, we describe the design, synthesis, and biological screening of a small library of compounds that led to the identification of four triarylmethyl amines as potent inhibitors of apoE production in CCF-STTG1 astrocytoma cells.
- Singh, Mandeep,Schott, Jason T.,Leon, Martin A.,Granata, Robert T.,Dhah, Harkiran K.,Welles, Jason A.,Boyce, Michelle A.,Oseni-Olalemi, Hafeez S.,Mordaunt, Charles E.,Vargas, Anthony J.,Patel, Nilay V.,Maitra, Santanu
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p. 6252 - 6255
(2012/10/29)
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- MELANIN PRODUCTION INHIBITOR
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Disclosed is a melanin production inhibitor which has an excellent inhibitory activity on the production of melanin and is highly safe. The melanin production inhibitor comprises a compound represented by general formula (1) (excluding clotrimazole), and/or a pharmacologically acceptable salt thereof. In the formula, A1, A2 and A3 are independently selected from a hydrogen atom, an aryl group which may have a substituent, and an aromatic heterocyclic group which may have a substituent, wherein at least one of A1, A2 and A3 is selected from the aryl group and the aromatic heterocyclic group, the total number of carbon atoms contained in A1, A2 and A3 is 6 to 50 and, when at least two of A1, A2 and A3 represent the aryl groups or the aromatic heterocyclic groups, the adjacent two aryl or aromatic heterocyclic groups may be bound to each other via an alkyl chain or an alkenyl chain to form a ring; m represents an integer of 0 to 2; X represents a hetero atom, a hydrogen atom, or a carbon atom; R1 and R2 are independently selected from a hydrogen atom and an oxo group, wherein when one of R1 and R2 is an oxo group, the other is not present; and R3 is selected from a hydrogen atom, and a C1-8 hydrocarbon group in which one or some of hydrogen atoms or carbon atoms may be substituted by a hetero atom or hetero atoms, wherein the number of R3's present in the compound corresponds to the number of X's and, when two or more R3's are present, the R3's are independently present and the adjacent two R3's may be bound to each other to form, together with X, a ring, and the terminal of R3 may be bound to a carbon atom to which A1, A2 and A3 are bound, thereby forming a ring.
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- Electrophilic Reactivity of the Triphenylmethyl Carbocation in Aqueous Solutions
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The triphenylmethyl (trityl) carbocation has been generated as a transient intermediate by laser flash photolysis of 1:2 (v/v) acetonitrile:water solutions of trityl acetate and trityl 4-cyanophenyl ether.Identification of the transient as the free carbocation in the ground state was based on its characteristic absorption spectrum and upon conductivity changes.Rate constants have been measured for the reaction of the cation in this solvent with a series of ionic and neutral nucleophiles.The solvent rate constant at 20 deg C is 1.5 x 105 s-1.Azide ions reacts at 4.1 x 109 M-1s-1; the directly measured azide:water ratio is compared to literature values determined by product analysis.Chloride ion reacts at 2 x 106 M-1 s-1; with bromide the equilibrium addition can be observed with k(comb) = 5 x 106 M-1 s-1 and k(ion) for Ph3CBr = 8 x 105 s-1.Rate constants do not adhere to the N+ relationship.This predicts a slope of unity in a plot of log k(Ph3C+) vs.N+, with the better nucleophiles reacting at the 1010 encounter-controlled limit.Azide is the only nucleophile of those studied to approach this.Sulfite and thiolate ions, which are better N+ nucleophiles, react at 2-3 x 108 M-1s-1, while amines react in the 106-107 M-1s-1 range.The plot vs.N+ has a slope of 0.3-0.4.One explanation is that rate constants for the better nucleophiles do level, but this occurs considerably below the 1010 limit.Alternatively, the less than unit slope is real and this more reactive cation, in contrast to more stable analogues, is exhibiting selectivity.
- McClelland, Robert A.,Banait, Narinder,Steenken, Steen
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p. 7023 - 7027
(2007/10/02)
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