- Photolabile calixarene-based rosette
-
A model calix[4]arene-based rosette carrying two alternating photocleavable dithianyl-hydroxy-methyl moieties and two benzophenonecarboxylates was synthesized and shown to be capable of photoinduced fragmentation, with efficiency comparable to that of the
- Li, Zaiguo,Chiu, Huy,Kutateladze, Andrei G.
-
-
Read Online
- Photosensitizers covalently anchored to the silica surface: Modulation of the excited state efficiency through electron transfer from the linking arm or from the surface.
-
Benzophenone derivatives have been anchored on silica in different ways. The so obtained heterogeneous as well as the corresponding homogeneous triplet photosensitizers have been tested in the triplet state isomerization of trans to cis stilbene. A photoinduced electron transfer originating from the amino groups on the linking arm or not the silica surface is found to modulate the sensitizer efficiency.
- Ayadim,Soumillion
-
-
Read Online
- Ni-Catalyzed Aryl Sulfide Synthesis through an Aryl Exchange Reaction
-
A Ni-catalyzed aryl sulfide synthesis through an aryl exchange reaction between aryl sulfides and a variety of aryl electrophiles was developed. By using 2-pyridyl sulfide as a sulfide donor, this reaction achieved the synthesis of aryl sulfides without using odorous and toxic thiols. The use of a Ni/dcypt catalyst capable of cleaving and forming aryl-S bonds was important for the aryl exchange reaction between 2-pyridyl sulfides and aryl electrophiles, which include aromatic esters, arenol derivatives, and aryl halides. Mechanistic studies revealed that Ni/dcypt can simultaneously undergo oxidative additions of aryl sulfides and aromatic esters, followed by ligand exchange between the generated aryl-Ni-SR and aryl-Ni-OAr species to furnish aryl exchanged compounds.
- Isshiki, Ryota,Kurosawa, Miki B.,Muto, Kei,Yamaguchi, Junichiro
-
supporting information
p. 10333 - 10340
(2021/07/21)
-
- Synthesis of N-trifluoromethyl amides from carboxylic acids
-
Found in biomolecules, pharmaceuticals, and agrochemicals, amide-containing molecules are ubiquitous in nature, and their derivatization represents a significant methodological goal in fluorine chemistry. Trifluoromethyl amides have emerged as important functional groups frequently found in pharmaceutical compounds. To date, there is no strategy for synthesizing N-trifluoromethyl amides from abundant organic carboxylic acid derivatives, which are ideal starting materials in amide synthesis. Here, we report the synthesis of N-trifluoromethyl amides from carboxylic acid halides and esters under mild conditions via isothiocyanates in the presence of silver fluoride at room temperature. Through this strategy, isothiocyanates are desulfurized with AgF, and then the formed derivative is acylated to afford N-trifluoromethyl amides, including previously inaccessible structures. This method shows broad scope, provides a platform for rapidly generating N-trifluoromethyl amides by virtue of the diversity and availability of both reaction partners, and should find application in the modification of advanced intermediates.
- Flavell, Robert R.,Liu, Jianbo,Parker, Matthew F. L.,Toste, F. Dean,Wang, Sinan,Wilson, David M.
-
supporting information
p. 2245 - 2255
(2021/08/12)
-
- Palladium-Catalyzed Chlorocarbonylation of Aryl (Pseudo)Halides Through In Situ Generation of Carbon Monoxide
-
An efficient palladium-catalyzed chlorocarbonylation of aryl (pseudo)halides that gives access to a wide range of carboxylic acid derivatives has been developed. The use of butyryl chloride as a combined CO and Cl source eludes the need for toxic, gaseous carbon monoxide, thus facilitating the synthesis of high-value products from readily available aryl (pseudo)halides. The combination of palladium(0), Xantphos, and an amine base is essential to promote this broadly applicable catalytic reaction. Overall, this reaction provides access to a great variety of carbonyl-containing products through in situ transformation of the generated aroyl chloride. Combined experimental and computational studies support a reaction mechanism involving in situ generation of CO.
- Bismuto, Alessandro,Boehm, Philip,Morandi, Bill,Roediger, Sven
-
supporting information
p. 17887 - 17896
(2020/08/19)
-
- Formamide catalyzed activation of carboxylic acids-versatile and cost-efficient amidation and esterification
-
A novel, broadly applicable method for amide C-N and ester C-O bond formation is presented based on formylpyrrolidine (FPyr) as a Lewis base catalyst. Herein, trichlorotriazine (TCT), which is the most cost-efficient reagent for OH-group activation, was employed in amounts of ≤40 mol% with respect to the starting material (100 mol%). The new approach is distinguished by excellent cost-efficiency, waste-balance (E-factor down to 3) and scalability (up to >80 g). Moreover, high levels of functional group compatibility, which includes acid-labile acetals and silyl ethers, are demonstrated and even peptide C-N bonds can be formed. In comparison to reported amidation procedures using TCT, yields are considerably improved (for instance from 26 to 91%) and esterification is facilitated for the first time in synthetically useful yields. These significant enhancements are rationalized by activation by means of acid chlorides instead of less electrophilic acid anhydride intermediates.
- Huy, Peter H.,Mbouhom, Christelle
-
p. 7399 - 7406
(2019/08/20)
-
- Nickel-Catalyzed Decarbonylative Cyanation of Acyl Chlorides
-
Ni-catalyzed decarbonylative cyanation of acyl chlorides with trimethylsilyl cyanide has been achieved. This transformation is applicable to the synthesis of an array of nitrile compounds bearing a wide range of functional groups under neutral conditions. The step-by-step experimental studies revealed that the reaction sequences of the present catalytic reaction are oxidative addition, transmetalation, decarbonylation, and reductive elimination.
- Wang, Zhenhua,Wang, Xiu,Ura, Yasuyuki,Nishihara, Yasushi
-
supporting information
p. 6779 - 6784
(2019/08/26)
-
- Palladium-Catalyzed Decarbonylative Difluoromethylation of Acid Chlorides at Room Temperature
-
Methods for the direct synthesis of difluoromethylated arenes are sparse, despite the importance of the difluoromethyl group in medical, agro-, and materials chemistry. A palladium-catalyzed decarbonylative cross-coupling reaction of acid chlorides with a difluoromethyl zinc reagent is achieved to access difluoromethylated compounds. The transformation proceeds at room temperature and shows broad functional group tolerance, thus providing a general and efficient method for decarbonylative difluoromethylation of a wide range of aromatic carboxylic acids.
- Pan, Fei,Boursalian, Gregory B.,Ritter, Tobias
-
supporting information
p. 16871 - 16876
(2018/11/23)
-
- Structure-activity relationship study and optimisation of 2-aminopyrrole-1-benzyl-4,5-diphenyl-1H-pyrrole-3-carbonitrile as a broad spectrum metallo-β-lactamase inhibitor
-
A SAR study on derivatives of 2-amino-1-benzyl-4,5-diphenyl-1H-pyrrole-3-carbonitrile 5a revealed that the 3-carbonitrile group, vicinal 4,5-diphenyl and N-benzyl side chains of the pyrrole are important for the inhibitory potencies of these compounds against members representing the three main subclasses of metallo-β-lactamases (MBLs), i.e. IMP-1 (representing the B1 subgroup), CphA (B2) and AIM-1 (B3). Coupling of 5a with a series of acyl chlorides and anhydrides led to the discovery of two N-acylamide derivatives, 10 and 11, as the two most potent IMP-1 inhibitors in this series. However, these compounds are less effective towards CphA and AIM-1. The N-benzoyl derivative of 5a retained potent in vitro activity against each of MBLs tested (with inhibition constants in the low μM range). Importantly, this compound also significantly enhanced the sensitivity of IMP-1, CphA- or AIM-1-producing cell cultures towards meropenem. This compound presents a promising starting point for the development of a universal MBL inhibitor, targeting members of each of the major subgroups of this family of enzymes.
- McGeary, Ross P.,Tan, Daniel T.C.,Selleck, Christopher,Monteiro Pedroso, Marcelo,Sidjabat, Hanna E.,Schenk, Gerhard
-
p. 351 - 364
(2017/06/19)
-
- COMPOUND FOR TREATING CLOSTRIDIUM DIFFICILE
-
The invention relates to compounds, compositions and polymers comprising a first component adapted to promote germination of Clostridium difficile (C.diff) and a second component which acts as an antimicrobial agent. Said compounds, compositions and polymers are useful for destroying C.diff where conventional antimicrobial agents are unsuccessful. The compositions can be formulated as coating or materials which actively destroy C.diff which come into contact with it. The germination promotion is induced by bile salts. The invention also relates to the use of such materials as a treatment for C.diff associated diseases and toxic megacolon.
- -
-
Page/Page column 74; 75
(2016/06/14)
-
- METHODS AND COMPOSITIONS FOR SELECTIVE AND TARGETED CANCER THERAPY
-
Provided herein are methods and compositions for selective and targeted cancer therapy, in particular certain benzothiophenes, benzothiazoles, oxalamides, N-acyl ureas and chromones, and their use in selectively treating certain adenocarcinomas. In some embodiments, the selective toxicity of the compounds may be mediated through SCD1 and/or CYP450 such as CYP4F11.
- -
-
Page/Page column 171; 172
(2015/03/28)
-
- Novel Carbazole (Cbz)-Based Carboxylated Functional Monomers: Design, Synthesis, and Characterization
-
A series of novel functional carbazole (Cbz)-based carboxylated monomers were synthesized and characterized. A Clauson-Kaas procedure, a deprotection step, amide coupling, and hydrolysis were utilized as key chemical reactions towards the multistep synthesis of monomers in good to excellent isolated yields. The design strategy was further extended to complex carbazole-COOH monomers incorporated arylazo groups as photoreactive moieties. In addition, photoreactive hybrid carbazole (Cbz)-pyrrole (Pyr)-based carboxylated monomers, comprising a pyrrole core linking a carbazole and a photoreactive phenylazide or benzophenone moiety through an amide spacer in the molecular structure, were also synthesized. The latter can be utilized for surface modification of polymeric films in their monomeric form or as polymeric microparticles (MPs). Functional monomers: Novel functional carbazole-based carboxylated monomers were accessed using a Clauson-Kaas procedure, a deprotection step, amide coupling, and hydrolysis in a multistep synthesis. The design strategy was extended to complex carbazole-COOH monomers incorporating arylazo and phenylazide or benzophenone as photoreactive moieties, which can be utilized for functionalization/decoration of various polymeric and non-polymeric surfaces, matrices, and non-functional nanomaterials in their monomeric states or as polymeric microparticles (MPs).
- Mondal, Ejabul,Lellouche, Jean-Paul,Naddaka, Maria
-
p. 489 - 496
(2015/10/05)
-
- METHODS AND COMPOSITIONS FOR BONDING SILICONE POLYMERS TO HAIR AND NAILS
-
Methods for covalently binding a silicone polymer to hair or nails using UV light, a catalyst, a reactive solution, and compositions related thereto. The methods can include synthesizing a photo-reactive silicone and bonding the photo-reactive silicone po
- -
-
Paragraph 0134
(2014/05/07)
-
- Synthesis of OSW-1 derivatives by site-selective acylation and their biological evaluation
-
A strategy to site-selectively monoacylate an antitumor saponin OSW-1 was developed using an organotin reagent to rapidly access its derivatives that are useful as chemical probes. 4″-O-Acylated OSW-1 derivatives bearing a fluorophore, an alkyne tag, or biotin were prepared in good yields and were shown to maintain highly cytotoxic activity.
- Sakurai, Kaori,Takeshita, Tomoya,Hiraizumi, Masato,Yamada, Rika
-
supporting information
p. 6318 - 6321
(2015/02/19)
-
- BRUTON'S TYROSINE KINASE INHIBITORS
-
Disclosed herein are compounds that form covalent bonds with Bruton's tyrosine kinase (BTK). Methods for the preparation of the compounds are disclosed. Also disclosed are pharmaceutical compositions that include the compounds. Methods of using the BTK inhibitors are disclosed, alone or in combination with other therapeutic agents, for the treatment of autoimmune diseases or conditions, heteroimmune diseases or conditions, cancer, including lymphoma, and inflammatory diseases or conditions. (Formula I)
- -
-
Page/Page column 128
(2014/05/24)
-
- METHODS AND COMPOSITIONS FOR BONDING SILICONE POLYMERS TO HAIR AND NAILS
-
Methods for covalently binding a silicone polymer to hair or nails using UV light, a catalyst, a reactive solution, and compositions related thereto. The methods can include synthesizing a photo-reactive silicone and bonding the photo-reactive silicone po
- -
-
Page/Page column 38
(2013/04/25)
-
- 3-Mercapto-1,2,4-triazoles and N-acylated thiosemicarbazides as metallo-β-lactamase inhibitors
-
The production of β-lactamases is an effective strategy by which pathogenic bacteria can develop resistance against β-lactam antibiotics. While inhibitors of serine-β-lactamases are widely used in combination therapy with β-lactam antibiotics, there are no clinically available inhibitors of metallo-β-lactamases (MBLs), and so there is a need for the development of such inhibitors. This work describes the optimisation of a lead inhibitor previously identified by fragment screening of a compound library. We also report that thiosemicarbazide intermediates in the syntheses of these compounds are also moderately potent inhibitors of the IMP-1 MBL from Pseudomonas aeruginosa. The interactions of these inhibitors with the active site of IMP-1 were examined using in silico methods.
- Faridoon,Hussein, Waleed M.,Vella, Peter,Islam, Nazar Ul,Ollis, David L.,Schenk, Gerhard,McGeary, Ross P.
-
supporting information; experimental part
p. 380 - 386
(2012/02/04)
-
- Penicillin inhibitors of purple acid phosphatase
-
Purple acid phosphatases (PAPs) are binuclear metallohydrolases that have a multitude of biological functions and are found in fungi, bacteria, plants and animals. In mammals, PAP activity is linked with bone resorption and over-expression can lead to bone disorders such as osteoporosis. PAP is therefore an attractive target for the development of drugs to treat this disease. A series of penicillin conjugates, in which 6-aminopenicillanic acid was acylated with aromatic acid chlorides, has been prepared and assayed against pig PAP. The binding mode of most of these conjugates is purely competitive, and some members of this class have potencies comparable to the best PAP inhibitors yet reported. The structurally related penicillin G was shown to be neither an inhibitor nor a substrate for pig PAP. Molecular modelling has been used to examine the binding modes of these compounds in the active site of the enzyme and to rationalise their activities.
- Faridoon,Hussein, Waleed M.,Ul Islam, Nazar,Guddat, Luke W.,Schenk, Gerhard,McGeary, Ross P.
-
supporting information; experimental part
p. 2555 - 2559
(2012/05/20)
-
- Polypeptide microparticles having sustained release characteristics, methods and uses
-
The invention provides polypeptide microparticles having control release features, particular methods for the preparation of such microparticles, and drug delivery systems that include polypeptide microparticles.
- -
-
-
- Pyrrolobenzodiazepine pyridine carboxamides and derivatives as follicle-stimulating hormone receptor antagonists
-
This invention provides pyrrolobenzodiazepine pyridine carboxamides selected from those of Formula (1), which act as follicle stimulating hormone receptor antagonists. The invention also provides pharmaceutical compositions and methods of treatment utilizing the compounds of Formulae (1) and (2).
- -
-
Page/Page column 45
(2010/11/25)
-
- Biaromatic ligand activators of PPARgamma receptors
-
Novel pharmaceutical/cosmetic compositions contain at least one biaromatic ligand activator of a PPARγ receptor, such biaromatic ligand having the structural formula (I): and are well suited, inter alia, for regulating and/or restoring skin lipid metabolism, for treating a wide variety of dermatological afflictions, and for preventing and/or treating the signs of aging and/or dry skin.
- -
-
-
- Photoactivatable nucleic acids
-
A photoactivatable nucleic acid derivative composition in which one or more photoreactive group(s) are bound to a natural or synthetic nucleic acid. The photoreactive groups can be bound to the nucleic acid before, during or after its formation, and can t
- -
-
-
- Latent reactive blood compatible agents
-
A reagent and related method for use in passivating a biomaterial surface, the reagent including a latent reactive group and a bifunctional aliphatic acid (e.g., fatty acid), in combination with a spacer group linking the latent reactive group to the alip
- -
-
-
- Medicament incorporation matrix
-
A coating composition, in both its uncrosslinked and crosslinked forms, for use in delivering a medicament from the surface of a medical device positioned in vivo. Once crosslinked, the coating composition provides a gel matrix adapted to contain the medi
- -
-
-
- Target molecule attachment to surfaces
-
Method and reagent composition for covalent attachment of target molecules, such as nucleic acids, onto the surface of a substrate. The reagent composition includes groups capable of covalently binding to the target molecule. Optionally, the composition c
- -
-
-
- PHOTOACTIVATABLE NUCLEIC ACID DERIVATIVES
-
A photoactivatable nucleic acid derivative composition in which one or more photoreactive group(s) are bound to a natural or synthetic nucleic acid. The photoreactive groups can be bound to the nucleic acid before, during or after its formation, and can t
- -
-
-
- Acetal benzylmaltosides as inhibitors of smooth muscle cell proliferation
-
This invention provides smooth muscle cell proliferation inhibitors of formula I having the structure with the variables defined herein.
- -
-
Page column 44
(2010/01/30)
-
- TARGET MOLECULE ATTACHMENT TO SURFACES
-
Method and reagent composition for covalent attachment of target molecules, such as nucleic acids, onto the surface of a substrate. The reagent composition includes groups capable of covalently binding to the target molecule. Optionally, the composition c
- -
-
-
- Polybifunctional reagent having a polymeric backbone and photoreactive moieties and bioactive groups
-
A polybifunctional reagent is provided having a polymeric backbone, one or more pendent photoreactive moieties, and two or more pendent bioactive groups. The reagent can be activated to form a bulk material or can be brought into contact with the surface of a previously formed biomaterial and activated to form a coating. The pendent bioactive groups function by promoting the attachment of specific molecules or cells to the bulk material or coated surface. Bioactive groups can include proteins, peptides, carbohydrates, nucleic acids and other molecules that are capable of binding noncovalently to specific and complimentary portions of molecules or cells.
- -
-
-
- Probes for narcotic receptor mediated phenomena. 23. Synthesis, opioid receptor binding, and bioassay of the highly selective δ agonist (+)-4- [(αR)-α-((2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl)-3-methoxybenzyl]N,N- diethylbenzamide (SNC 80) and related novel nonpeptide δ opioid receptor ligands
-
The highly selective delta (δ) opioid receptor agonist SNC 80 [(+)-4- [(αR)-α-((2S,5R)-4-allyl-2,5-dimethyl-1-piperazinyl)-3-methoxybenzyl]-N,N- diethylbenzamide, (+)-21] and novel optically pure derivatives were synthesized from the enantiomers of 1-allyl-trans-2,5-dimethylpiperazine (2). The piperazine (±)-2 was synthesized, and its enantiomers were obtained on a multigram scale in >99% optical purity by optical resolution of the racemate with the camphoric acids. The absolute configuration of (+)-2 was determined to be 2S,5R by X-ray analysis of the salt with (+)-camphoric acid. Since the chirality of the starting material was known, and the relative configuration of compounds (-)-21, (-)-22, and (+)-23 were obtained by single-crystal X- ray analysis, the assignment of the absolute stereochemistry of the entire series could be made. Radioreceptor binding studies in rat brain preparations showed that methyl ethers (+)-21 (SNC 80) and (-)-25 exhibited strong selectivity for rat δ receptors with low nanomolar affinity to 6 receptors and only micromolar affinity for rat mu (μ) opioid receptors. Compounds (- )-21, (-)-22, and (-)-23 showed micromolar affinities for δ opioid receptors. The unsubstituted derivative (+)-22 and the fluorinated derivative (-)-27 showed >2659- and >2105-fold δ/μ binding selectivity, respectively. The latter derivatives are the most selective ligands described in the new series. Studies with some of the compounds described in the isolated mouse vas deferens and guinea pig ileum bioassays revealed that all were agonists with different degrees of selectivity for the δ opioid receptor. These data show that (+)-21 and (+)-22 are potent δ receptor agonists and suggest that these compounds will be valuable tools for further study of the δ opioid receptor at the molecular level, including its function and role in analgesia and drug abuse.
- Calderon, Silvia N.,Rice, Kenner C.,Rothman, Richard B.,Porreca, Frank,Flippen-Anderson, Judith L.,Kayakiri, Hiroshi,Xu, Heng,Becketts, Karen,Smith, Larren E.,Bilsky, Edward J.,Davis, Peg,Horvath, Robert
-
p. 695 - 704
(2007/10/03)
-
- Self-sensitized photolysis of N-(1-naphthoyl)-N-phenyl-O-(benzoyl-substituted benzoyl)hydroxylamines
-
The mechanism of intramolecular triplet-triplet (T-T) energy transfer and subsequent reaction in N,O-diacylhydroxylamines was investigated using the model compounds N-( 1 -naphthoyl)-N-phenyl-O-(benzoyl-substituted benzoyl)hydroxylamines (NPB) with self-sensitization abilities. An examination of the UV absorption and phosphorescence behavior as well as of energy-minimized conformations of these relatively flexible model compounds established that T-T energy transfer from the benzophenone chromophore to the naphthoyl chromophore occurs in a nearly unit efficiency exhibiting only phosphorescence derived from the latter chromophore in both methanol-ethanol (1 : 1 v/v) and 2-chlorobutane at 77 K and is more likely to proceed by a "through-space" mechanism than by a "through-bond" mechanism. The self-sensitized photolysis of NPB with 366 nm light in methanol at room temperature was found to give the fragmentation products, N-phenyl-1-naphthalenecarboxamide (PNA), benzophenone (BP), and benzoyl-substituted benzoic acids (BBA), whereas no BBA was detected in the photolysis in 1,2-dichloroethane and acetonitrile. The finding that the reaction of NPB is efficiently quenched by trans-stilbene according to the Stern-Volmer equation in both methanol and 1,2-dichloroethane indicates that all the products come from the first excited triplet state of the naphthoyl chromophore. On the other hand, the enhanced hydrogen bonding ability of the medium resulted in an increase in the quantum yield for the formation of BBA (ΦBBA) accompanied by a decrease in ΦBA holding the magnitude of ΦBBA+ΦBA nearly constant. But neither ΦPNA nor the quantum yield for the disappearance of NPB was subject to such a hydrogen-bonding effect. This intriguing result was explained in terms of a mechanism in which the N-O bond cleavage in triplet NPB gives a vibrationally excited triplet radical pair whose relaxation is very slow compared to decarboxylation of the caged benzoyl-substituted benzoyloxyl radical in 1,2-dichloroethane. Solvation of this vibrationally hot radical pair through hydrogen bonding substantially promotes its relaxation eventually affording BBA.
- Nagakubo, Hiroshi,Kubota, Gou,Kubo, Kanji,Kaneko, Tsuyoshi,Sakurai, Tadamitsu,Inoue, Hiroyasu
-
p. 2603 - 2611
(2007/10/03)
-
- Radiation-senstive, ethylenically unsaturated, copolymerizable compounds and their preparation
-
Radiation-sensitive, ethylenically unsaturated compounds and a process for their preparation. The ethylenically unsaturated organic compounds are of the general formula STR1 where R is alkyl, aryl or a radical R1 and R1 is a radical
- -
-
-
- Progestin 16α,17α-dioxolane ketals as molecular probes for the progesterone receptor: Synthesis, binding affinity, and photochemical evaluation
-
Chemical probes for steroid receptors have proven useful in providing molecular details about important hormone-receptor interactions. A series of progestin 16α,17α-dioxolane ketals of acetophenone or substituted acetophenones that bind to the progesterone receptor (PgR) with comparable or higher affinities than the natural ligand, progesterone, have been prepared and evaluated as potential in vitro and in vivo probes for the progesterone receptor. p-Azidoacetophenone ketal 6, the tetrafluoro analog 8, and the p- (benzoyl)acetophenone ketal 9 demonstrate the required combination of high relative binding affinity (RBA) (6 = 15%, 8 = 14%, 9 = 6.6%, progesterone = 13%, R5020 = 100%) and photoinactivation efficiency (6 = 80%, 8 = 77%, 9 = 29% at 30 min) required for potential photoaffinity labeling reagents for the PgR. The synthesis of azide 6 has been modified to accommodate a palladium- catalyzed tritium gas hydrogenolysis of an iodoaryl precursor in the final stage of the synthetic sequence; this procedure has been verified by hydrogenation. In addition, the progestin p-fluoroacetophenone ketal 10 was selected for preparation in fluorine-18-labeled form, on the basis of its high affinity for the PgR (RBA = 53%). Fluorine-18-labeled progestins may be evaluated as potential diagnostic imaging agents for PgR-positive breast tumors. The radiochemical syntheses and further biochemical results with the fluorine-18-labeled ketal 10 and the tritium-labeled aryl azide 6 will be presented in an accompanying paper and elsewhere.
- Kym,Carlson,Katzenellenbogen
-
p. 1111 - 1119
(2007/10/02)
-
- Intramolecular Triplet Energy Transfer in Ester-Linked Bichromophoric Azoalkanes and Naphthalenes
-
The photophysics of a series of compounds has been studied wherein a triplet sensitizer such as benzophenone (BB) or thioxanthone (TH) is linked via an ester group to an azoalkane such as 3,3,5,5-tetramethyl-1-pyrazoline (PY) or 2,3-diazabicyclooct
- Engel, Paul S.,Horsey, Douglas W.,Scholz, John N.,Karatsu, Takashi,Kitamura, Akihide
-
p. 7524 - 7535
(2007/10/02)
-
- Synthesis and anthelmintic activity of 3'-benzoylurea derivatives of 6-phenyl-2,3,5,6-tetrahydroimidazo[2,1-b]thiazole
-
Reaction of 3-amino derivatives of the nematocides tetramisole and levamisole with variously substituted benzoylisocyanates gave a series of benzoylureas I which were tested for activity against helminths and ectoparasites. Compounds bearing 2,6-difluoro and 4-trifluoromethyl substituents had potent nematocidal activity in both mice and sheep. No antiectoparasitic activity was observed.
- Weikert,Bingham Jr.,Emanuel,Fraser-Smith,Loughhead,Nelson,Poulton
-
p. 1630 - 1633
(2007/10/02)
-
- Use of N-haloamides as photoinitiators for free-radical polymerizations
-
Disclosed are N-haloamide photoinitiator compositions for free-radical polymerizations, comprising at least one compound of general formula (I):, , R - CO - NHX (I)wherein Rrepresents an optionally substituted alkyl, cycloalkyl, aryl, alkyl-aryl or aryl-alkyl or heterocyclic group and Xis Cl, Br or I.
- -
-
-
- Chemical Consequences of Single-Electron Oxidation of Phenylmesityldiazoethane
-
Both thermolysis and photolysis of 1-phenyl-2-mesityldiazoethane (PMDE) lead exclusively to products derived from facile hydrogen or mesityl migration subsequent to, or concurrent with, loss of N2.No detectable amounts of ketazine or any dimeric hydrocarbons are formed in these reactions -a result that is attributable to the steric hindrance about the diazo carbon in PMDE.Quite in contrast, the one-electron oxidation of this diazoalkane yields no monomeric products by simple hydrogen or mesityl migration; instead, ketazine and dimeric products are formed by two distinct paths.Dimerization of diazo radical cations followed by competing secondary reactions of the resulting dication is the favored path according for the major products.In a very much slower reaction, PMDE+. attacks neutral PMDE to yield ketazine.
- Little, Charles B.,Schuster, Gary B.
-
p. 7167 - 7175
(2007/10/02)
-
- INFLUENCE OF THE ANGULAR LINKAGE ON THE MESOMORPHIC PROPERTIES OF CHOLESTERYL ARYLBENZOATES.
-
Some cholesteryl esters of arylbenzoic acids incorporating angular linkage such as -Co-, -O-, -S-, and -CH//2-, were prepared, and the transition temperatures and heats determined. The cholesteric-isotropic transition temperatures are likely to correlate with the angular correlation parameters of these carboxylic acid moieties. The mesomorphic phenomena are discussed in terms of the molecular structure and electronic effect of these linkages.
- Koden,Takenaka,Kusabayashi
-
p. 137 - 150
(2007/10/02)
-
- Chemistry at Rigid Surfaces, 6. - Photochemically Induced Reactions with Surface-bound Sensitizers
-
AerosilR reacts with 3-triethoxysilylpropylamine to give Aminoaerosil (1) which can be converted into aerosils 2a - f by means of sensitizers containing carboxyl groups.The density of the functional groups on the surface which was determined by several methods clearly effects the reaction.On irradiation in 2-propanol, acetone was produced as well as the surface-bound pinacol, e. g. 4, which could be reoxidized by lead tetraacetate to give 2b.Hydrodimerization on the surface of 2b proceeds three times more slowly than with the homogeneous analogues.The photoreduction of 2b with a minor surface density, gave - in addition to 4 - the carbinol 8 and the mixed pinacol 9. - The aerosil with surface-bound p-acetylbenzoic acid (modified aerosil 2b) is investigated in comparison to the homogeneous system: experiments were made in (S)-p-menth-3-yl lactate and (R,S)-p-menth-3-yl-lactate.In both cases the surface-bound pinacol 4 was formed, and in the latter case a decrease in the optical activity of the lactate was observed. - With surface-bound sensitizers the following photochemically induced reactions were studied: a) the photosensitized addition of 2-propanol to maleic acid and diethyl maleate to give terebinic acid (12a) or its methyl ester, respectively; b) the sensitized cis/trans isomerization of maleic acid or diethyl fumarate; c) the sensitized cis/trans isomerization of 1,2-diphenylcyclopropane; d) the sensitized autoxidation of 2,5-dimethylfuran. - All four reactions, although slower, yield the same products as in the analogous homogeneous system.In reaction b), c), and d) the efficiency factor WF (ratio of reaction rates in homo- and heterogeneous system) and the reutilization factor SF (ratio of co nversions after a given time in the first and second experiment) was determined for the heterogeneous sensitizer.
- Horner, Leopold,Klaus, Joachim
-
p. 792 - 810
(2007/10/02)
-