- Synthesis and Solution Properties of a Double-Tailed Quaternary Ammonium Surfactant with a Protrudent Head Group
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Modification of the molecular structure of surfactants is an effective method for exploring their self-assembly. A double-tailed quaternary ammonium surfactant with a protrudent head group, namely 2-octyldecyltrimethylammonium bromide (2-ODTAB) was synthesized, and the solution properties were investigated by surface tension, dynamic light scattering, and cryogenic TEM. A comparative study was also performed on the traditional double-tailed homologue surfactants dioctyldimethylammonium bromide (8-8), didecyldimethylammonium bromide (10-10), and didodecyldimethylammonium bromide (12-12). The results showed that 2-ODTAB was more effective at lowering surface tension and in forming stable vesicles than traditional double-tailed surfactants with similar alkyl chain length. The reason is attributed to the improved structure of 2-ODTAB, in which the two alkyl tails are connected to the ionic head group by one carbon atom. This structure imparts more freedom to the head group and thus favors formation of more stable aggregates at low concentration. In addition, the lower limit of the alkyl chain length of the double-tailed surfactants for forming stable vesicles was illustrated.
- Song, Binglei,Xu, Zonghui,Yu, Xiaona,Chen, Shuyi,Li, Shunan,Shi, Rongzhen,Cui, Zhenggang
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Read Online
- Novel Xylene-Linked Maltoside Amphiphiles (XMAs) for Membrane Protein Stabilisation
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Membrane proteins are key functional players in biological systems. These biomacromolecules contain both hydrophilic and hydrophobic regions and thus amphipathic molecules are necessary to extract membrane proteins from their native lipid environments and
- Cho, Kyung Ho,Du, Yang,Scull, Nicola J.,Hariharan, Parameswaran,Gotfryd, Kamil,Loland, Claus J.,Guan, Lan,Byrne, Bernadette,Kobilka, Brian K.,Chae, Pil Seok
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Read Online
- Preparation of mono-substituted malonic acid half oxyesters (SMAHOs)
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The use of mono-substituted malonic acid half oxyesters (SMAHOs) has been hampered by the sporadic references describing their preparation. An evaluation of different approaches has been achieved, allowing to define the best strategies to introduce diversity on both the malonic position and the ester function. A classical alkylation step of a malonate by an alkyl halide followed by a monosaponification gave access to reagents bearing different substituents at the malonic position, including functionalized derivatives. On the other hand, the development of a monoesterification step of a substituted malonic acid derivative proved to be the best entry for diversity at the ester function, rather than the use of an intermediate Meldrum acid. Both these transformations are characterized by their simplicity and efficiency, allowing a straightforward access to SMAHOs from cheap starting materials.
- Condon, Sylvie,Le Gall, Erwan,Pichon, Christophe,Presset, Marc,Xavier, Tania
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supporting information
p. 2085 - 2094
(2021/09/02)
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- Synthesis of protected α-amino acids: Via decarboxylation amination from malonate derivatives
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A general and efficient strategy for the synthesis of protected α-amino acids is reported. The method uses malonate derivatives as the starting materials and Cs2CO3 as a base at 60 degrees, giving α-amino acid derivatives in moderate yields by releasing CO2. This methodology shows broad substrate scope (primary and secondary acids), excellent functional group tolerance and high efficiency to give the desired products under mild reaction conditions. It also allows the construction of β and γ-amino acids and other unnatural products.
- Dai, Qipu,Fu, Hui,Hu, Changwen,Li, Peihe,Li, Xiaoying,Wang, Zheng
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p. 4439 - 4446
(2020/10/20)
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- Direct Copper-Catalyzed C-H Monofluoroalkylation of Benzoxazoles with 1-Fluoro-1-haloalkanes
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The first example of direct C–H bond monofluoroalkylation with 1-fluoro-1-haloalkanes with no adjacent functional groups and with β-hydrogens has been developed. This transformation offers a straightforward route for the synthesis of a series of monofluoroalkylated benzoxazoles.
- Li, Wei,Varenikov, Andrii,Gandelman, Mark
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supporting information
p. 3138 - 3141
(2020/03/13)
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- NOVEL XYLENE-BASED AMPHIPHILIC COMPOUND AND USE THEREOF
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The present invention relates to a xylene-based amphiphilic compound, a method for preparing the same, and a method for extracting, solubilizing, stabilizing or crystallizing a membrane protein using the same. By using the xylene-based compound according to the present invention, a membrane protein may be stably stored in an aqueous solution for a long time, and may be applied in functional and structural analyses. The structural and functional analysis of the membrane protein is one of the fields of highest interest in biology and chemistry, and the xylene-based compound according to the present invention can be applied in research on protein structure that is closely related to development of a new drug.
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Paragraph 0167; 0168; 0178; 0179; 0188
(2018/10/19)
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- Metal-Organic Framework Anchored with a Lewis Pair as a New Paradigm for Catalysis
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Lewis pair (LP) chemistry has shown broad applications in the catalysis field. However, one significant challenge has been recognized as the instability for most homogeneous LP catalysts upon recycling, thus inevitably leading to dramatic loss in catalytic activity. Additionally, current heterogeneous LP catalysts suffer from low surface area, which largely limits their catalytic efficiency, thereby restricting their potential applications. In this work, we report the successful introduction of LPs, classical and frustrated, into a metal-organic framework (MOF) that features high surface and ordered pore structure via a stepwise anchoring strategy. Not only can the LP be stabilized by the strong coordination interaction between the LP and MOF, but the resultant MOF-LP also demonstrates excellent catalysis performance with interesting size and steric selectivity. Given the broad applicability of LPs, our work therefore paves a way for advancing MOF-LP as a new paradigm for catalysis. Lewis pairs (LPs), classical and frustrated, are excellent prospects in catalysis, organic syntheses, biology, and material sciences. However, the instability of most LP catalysts leads to a dramatic loss in activities, thereby largely restricting their industrial applications. As robust porous materials, metal-organic frameworks (MOFs) offer a platform to stabilize homogeneous catalysts. Here, we show a strategy that grafts the LP catalyst on the MOF to minimize loss of LPs during catalysis and recycling. Our work reveals the enormous potential of MOFs as an appealing paradigm for the construction of efficient heterogeneous catalysts with interesting steric and size selectivity worthy of exploration. In addition, the strategies for anchoring a LP into a MOF as contributed herein can be readily applied for the task-specific design of functional catalysis materials for various applications. Lewis pairs (LPs), classical and frustrated, have been successfully introduced into and stabilized in a metal-organic framework (MOF). Benefiting from the robust framework and tunable porous structure of MOFs, the resultant MOF-LP demonstrates not only great recyclability but also excellent performance in the catalytic reduction of imines and hydrogenation of alkenes. The combination of LP and MOF therefore lays a foundation for developing a MOF-LP as a new paradigm for catalysis, particularly heterogeneous catalysis.
- Niu, Zheng,Bhagya Gunatilleke, Wilarachchige D.C.,Sun, Qi,Lan, Pui Ching,Perman, Jason,Ma, Jian-Gong,Cheng, Yuchuan,Aguila, Briana,Ma, Shengqian
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p. 2587 - 2599
(2018/12/02)
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- Metal-free hydrogenation of electron-poor allenes and alkenes
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The poorer, the better: A metal-free catalytic procedure for the reduction of electron-poor allenes and alkenes has been developed. The method employs a frustrated Lewis pair based catalyst. 1,4-Diazabicyclo[2.2.2]octane (DABCO)/B(C6F5)3 was shown to be the best combination in optimization studies. Copyright
- Ines, Blanca,Palomas, David,Holle, Sigrid,Steinberg, Sebastian,Nicasio, Juan A.,Alcarazo, Manuel
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supporting information
p. 12367 - 12369
(2013/02/22)
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- Unexpected stereoselective exchange of straight-chain fatty acyl-CoA α-protons by human α-methylacyl-CoA racemase 1A (P504S)
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α-Methylacyl-CoA racemase (AMACR; P504S) catalysed exchange of straight-chain fatty acyl-CoA α-protons. One α-proton was removed in each catalytic cycle, with the pro-S proton preferred. This reaction was most efficient for straight-chain substrates with longer side-chains. 2-Methyldecanoyl-CoA underwent α-proton exchange 3× more efficiently (as judged by Kcat/Km) than decanoyl-CoA.
- Sattar, Fouzia A.,Darley, Daniel J.,Politano, Francesco,Woodman, Timothy J.,Threadgill, Michael D.,Lloyd, Matthew D.
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supporting information; experimental part
p. 3348 - 3350
(2010/08/06)
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- Phosphinate, sulfonate, and sulfonamidate dipeptides as potential inhibitors of Escherichia coli aminopeptidase N
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In an effort to prepare novel inhibitors of bacterial aminopeptidase N (PepN), the phosphinate, propenylphosphinate, decylphosphinate, sulfonate, and sulfonamidate analogs of Ala-Ala were synthesized and tested as inhibitors. Phosphinate 1 was shown to inhibit PepN with a Ki of 10 μM, and propenylphosphinate 2 and decylphosphinate 3 inhibited PepN with a Ki of ca. 1 μM. Sulfonate and sulfonamidate analogs did not inhibit PepN.
- Yang, Ke-Wu,Golich, Frank C.,Sigdel, Tara K.,Crowder, Michael W.
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p. 5150 - 5153
(2007/10/03)
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- Catalytic radical addition of carbonyl compounds to alkenes by Mn(II)/Co(II)/O2 system
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The radical addition of enolizable carbonyl compounds such as malonates and malononitrile to alkenes was successfully achieved through a catalytic process using the Mn(II)/Co(II)/O2 system to afford the corresponding adducts in fair to good yields. Dimethyl malonate added to 1,5-cyclooctadiene to produce a fused bicycle compound.
- Hirase, Kouji,Iwahama, Takahiro,Sakaguchi, Satoshi,Ishii, Yasutaka
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p. 970 - 973
(2007/10/03)
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- Barbituric acid derivatives with antimetastatic and antitumor activity
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The invention is directed to barbituric acid derivatives having inhibitory activity for matrix maetalloproteases comprised of formula (I): pharmaceutical compositions thereof, processes for preparing the derivatives, and methods for treating diseases associated with elevated or uncontrolled levels of matrix metalloprotease activity, e.g., cancer, specifically tumor progression and tumor metastasis, inflammation, or as a method of contraception.
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Page column 12
(2010/01/21)
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- Synthesis of a tetraamido macrocycle ligand from a novel diamidodiol
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A new composition of matter for a diamidodiol and a method for preparing the diamidodiol. The exemplary diamidodiol has the formula C15H30N2O4 and is prepared by reacting a first quantity of 2-amino-2-methyl-1-propanol with a second quantity of a di-substituted malonyl dichloride (i.e., diethylmalonyl dichloride), preferably in ethyl acetate as solvent. A tetraamido macrocycle is prepared from the diamidodiol in two steps by oxidizing the diamidodiol to form a diacid followed by coupling using a known procedure of the diacid with an aryl diamine (e.g., 1,2-diaminobenzene) to yield the tetraamido macrocycle.
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(2010/02/05)
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- 3,4-Alkylenedioxypyrroles: Functionalized derivatives as monomers for new electron-rich conducting and electroactive polymers
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New functionalized derivatives of 3,4-ethylenedioxypyrrole (EDOP, 5a) and 3,4-(1,3-propylenedioxy) pyrrole (ProDOP, 5b) as especially electron-rich monomers which yield highly electroactive and stable conducting polymers useful for a diverse set of applications have been synthesized. N-Alkylations of ProDOP were carried out to yield a variety of ProDOP derivatives having alkyl, sulfonatoalkoxy, glyme, and glyme alcohol pendant chains. Iodization of EDOP and ProDOP via iodo-decarboxylation afforded iodo-functionalized derivatives useful for subsequent aryl coupling chemistry. N-Protection and formylation of EDOP, followed by Knoevenagel condensation of the resultant 2-formyl-EDOP with aryl acetonitrile derivatives, led to 1-cyano-2-(2-(3,4-ethylenedioxypyrryl))-1-(2-thienyl)vinylene (23) (Th-CNV-EDOP) and 1-cyano-2-(2-(3,4-ethylenedioxypyrryl))-1-(2-(3,4-ethylenedioxythienyl) vinylene (26) (EDOT-CNV-EDOP). A 14-crown-4-ether 34 based dioxypyrrole was synthesized with a cavity potentially useful for lithium ion coordination and sensing in the resultant electroactive polymer. C-Alkylated ProDOPs (43a, 43b, and 43c) containing octyl, ethylhexyl, and dioctyl substituents appended to the central methylene of the propylene bridge, were prepared as monomers for potentially soluble π-conjugated polymers.
- Zong,Reynolds
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p. 6873 - 6882
(2007/10/03)
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- Barbituric acid derivatives, processes for their production and pharmaceutical agents containing these compounds
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PCT No. PCT/EP96/05766 Sec. 371 Date Aug. 26, 1998 Sec. 102(e) Date Aug. 26, 1998 PCT Filed Dec. 20, 1996 PCT Pub. No. WO97/23465 PCT Pub. Date Jul. 3, 1997Compounds of formula I, useful as matrix metalloprotease inhibitors, wherein X, Y and Z are each oxygen; R1 is selected from the group consisting of (a) n-octyl, (b) n-decyl, (c) biphenyl and (d) (4-phenoxy)phenyl, wherein the terminal monocycle for moieties (c)-(d) is unsubstituted or substituted by a substituent selected from the group consisting of -NH2, -NO2, -SO2NH2, -SO2CH3, acetyl, hydroxy, methoxy, ethoxy, cyano and halogen; R2 and R3 are each hydrogen; and R4 and R5, together with the nitrogen atom to which they are bound, form a piperazinyl or piperidyl ring, wherein the piperazinyl ring is substituted in the 4-position with a substituent selected from the group consisting of (a) a 6-membered aromatic monocycle having 0, 1 or 2 nitrogen atoms and the remainder of the atoms in the monocycle being carbon and (b) hydroxy-C1-C6 alkyl, wherein the monocycle is unsubstituted or substituted by a substituent selected from the group consisting of halogen, -NH2, -NO2, -SO2NH2, -SO2CH3, acetyl and cyano.
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- The synthesis and electro-optic properties of liquid crystalline 2- (2,3-difluorobiphenyl-4'-yl)-1,3-dioxanes
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Fifty-six novel alkyl and/or alkoxy disubstituted 2-(2,3- difluorobiphenyl-4'-yl)-1,3-dioxanes (DFBPD) were prepared. Smectic C and nematic mesophases were exhibited by most of the alkyl-alkoxy homologues. Conversely, most of the dialkyl compounds exhibited smectic C, smectic A and nematic phases. The birefringence (Δn), dielectric anisotropy (Δε), spontaneous polarisation and response times of two ferroelectric mixtures formulated from the dioxanyl systems were determined. The birefringence results were compared with eight other groups of mixtures where the materials were based on different core systems. The overall electro-optic properties of the DFBPDs were found to be comparable to the best of the eight most commonly used materials in ferroelectric display devices.
- Dong, Chu Chuan,Styring, Peter,Goodby, John W.,Chan, Lawrence K. M.
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p. 1669 - 1677
(2007/10/03)
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- Cyclobutanecarboxylic acid derivatives and liquid crystalline compositions containing them
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An optically inactive cyclobutanecarboxylic acid derivative of the general formula STR1 wherein R1 is a hydrogen atom or a straight or branched chain alkyl group having 1-14 carbon atoms, R2 is a straight or branched chain alkyl grou
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- Mesomorphic compound, liquid crystal composition, liquid crystal device, display apparatus and display method
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A mesomorphic compound of the formula (I) according to Claim 1 and an optically active compound of the formula (II) according to Claim 2 are suitable as a component for a liquid crystal composition providing improved response characteristics and having an
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- Liquid crystal compounds and liquid crystal display devices
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Novel anti-ferroelectric liquid crystal compounds represented by the following general formula (I) and a liquid crystal display element wherein such a compound is used. STR1 Ph represents a phenylene group, R represents a straight-chain alkyl group having
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- STEREOSPECIFIC DISPLACEMENT OF SULFUR FROM CHIRAL CENTERS. ACTIVATION VIA THIAPHOSPHONIUM SALTS.
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The first general method for direct displacement of sulfur from chiral carbon centers has been developed.Chiral mercaptans are readily converted to the corresponding thiaphosphonium salts by treatment with t-butyl hypochlorite and hexamethylphosphorous triamide.Metathesis with ammonium hexafluorophosphate provides stable, isolable, crystalline salts which undergo clean nucleophilic diplacement with a variety of heteroatom and carbon based nucleophiles, affording products in which the stereochemistry has been inverted.
- Krafft, Grant A.,Siddall, Thomas L.
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p. 4867 - 4870
(2007/10/02)
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- FACTORS GOVERNING PRODUCT DISTRIBUTION IN THE OXIDATION OF ALKENES BY MANGANESE(III) ACETATE IN ACETIC ACID AND ACETIC ANHYDRIDE
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A systematic investigation has been carried out into the effect of different reaction parameters on the oxidation of oct-1-ene by manganese(III) acetate in acetic acid and acetic anhydride.The most important factor in dictating the ratio of products is the composition of the solvent.In the absence of anhydride γ-decanolactone is virtually the sole product.Even small quantitites of anhydride lead to the lactone being replaced by other products derived from cationic intermediates C6H13CH(1+)CH2COX (X = OH or OAc).Further increases in the amount of anhydride encourage the formation of decanoic acid until, in 90percent anhydride, this becomes the predominant product.The results cannot be interpreted simply in terms of competition for the alkene by the radicals (.)CH2CO2H and (.)CH2COOCOCH3.Decanoic acid formation is also favoured by low temperatures, low concentration of oxidants, and by the addition of acetate ions.A comparision is made of the efficiency of addition when the initiating species is manganese(III) or a peroxide.
- Midgley, Gary,Thomas, C. Barry
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p. 1537 - 1544
(2007/10/02)
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- LIQUID CRYSTAL MATERIALS WITH SULFUR ATOMS INCORPORATED IN THE PRINCIPAL STRUCTURE: 1. NEW LIQUID CRYSTAL COMPOUNDS WITH 1,3-DITHIANE RING.
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2-(p-Substituted phenyl)-5-alkyl-1,3-dithianes, new liquid crystals, were synthesized by the thioacetalization of the corresponding aldehydes and dithiols. These compounds have characteristic supercooling states, exhibit monotropic liquid crystal phases even in the case of long terminal alkyl substituents. The mesomorphic characteristics of these compounds were different from those of the corresponding 1,3-dioxanes, this must originate in the difference in the molecular width caused by the difference in the atomic volume between sulfur and oxygen.
- Haramoto,Nobe,Kamogawa
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p. 1966 - 1969
(2007/10/02)
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- SYNTHESES OF 3,7-DIMETHYLPENTADECAN-2-OLS FROM INTERMEDIATES FORMED FROM CO-OLIGOMERISATION REACTIONS OF BUTADIENE WITH DIETHYL MALONATE AND ACETALDEHYDE
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The products of the reaction of butadiene with diethyl malonate catalysed by a palladium complex and of butadiene with acetaldehyde catalysed by a nickel(O) complex have been used in two syntheses of 3,7-dimethylpentadecan-2-ol.
- Baker, Raymond,Winton, Peter M.
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p. 1175 - 1178
(2007/10/02)
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- Dioxanylphenyl benzoate liquid crystal compounds
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Compounds of the formula: STR1 wherein R1 is a straight chain alkyl group of 1 to 10 carbon atoms and R2 is an alkyl, alkoxy, acyloxy, alkyl carbonato group having 1 to 10 carbon atoms, CN or NO2. The dioxanylphenyl benzoa
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