ABSTRACT
ABSTRACT
[(Trimethylsilyl)propargyl)]diisobutyltelluronium bromide (1), after being treated with alkyl- or aryllithium reagent, undergoes a lithium-tellurium exchange reaction via an unstable transient tetraorganyltellurium intermediate, and the... more
[(Trimethylsilyl)propargyl)]diisobutyltelluronium bromide (1), after being treated with alkyl- or aryllithium reagent, undergoes a lithium-tellurium exchange reaction via an unstable transient tetraorganyltellurium intermediate, and the in situ generated lithium species reacts with carbonyl compounds to give (trimethylsilyl)propargyl alcohols 2 in high yields with high regioselectivity. However, when the telluronium salt 1 was treated with nonnucleophilic bases such as LDA or lithium 2,2,6,6-tetramethylpiperidide, the moderately stabilized silylated telluronium ylide formed. The silylated telluronium ylide reacted with carbonyl compounds to afford (trimethylsilyl)alkynyl epoxides 11 in good to excellent yields with high cis stereoselectivity.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full... more
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
We propose a simple method of characterizing the (Lewis) acid/base behavior of oil-soluble nonionic surfactants at the interface of nonpolar solvents with a polar phase. Using interfacial tensiometry, we probe the effective acidic and... more
We propose a simple method of characterizing the (Lewis) acid/base behavior of oil-soluble nonionic surfactants at the interface of nonpolar solvents with a polar phase. Using interfacial tensiometry, we probe the effective acidic and basic response of nonpolar surfactant solutions to contact with a variety of polar reference liquids. The measured interfacial tensions are used as experimental coefficients in a set of equations borrowed from the thermodynamic "surface energy component model" of van Oss, Chaudhury, and Good (vOCG), but used here in a more heuristic fashion and with a revised interpretation of the parameters extracted to describe the dispersive, acidic, and basic character of the sample. We test the proposed characterization method using alkane solutions of purified polyisobutylene succinimide (PIBS) surfactants with systematic structural variations, and observe that the inferred parameter values are consistent with, and sensitive to, subtle differences in th...
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In a carbon nanotube (CNT) thin film, CNTs form complicated networks with numerous junctions where individual CNTs intersect or simply contact other CNTs. This results in a significant reduction of the electrical conductivity of the film... more
In a carbon nanotube (CNT) thin film, CNTs form complicated networks with numerous junctions where individual CNTs intersect or simply contact other CNTs. This results in a significant reduction of the electrical conductivity of the film as compared with the intrinsic ...
ABSTRACT Diphenyltelluronium methylide, generated from methyldiphenyltelluronium tetraphenylborate 1 with LiTMP, reacted with carbonyl compounds to afford substituted oxiranes in moderate to good yields.
ABSTRACT In the presence of cesium carbonate, a variety of aldehydes can be epoxidized directly with allyl bromide at 50°C under solid-liquid phase transfer condition by use of a catalytic amount of diisobutyl telluride to afford vinyl... more
ABSTRACT In the presence of cesium carbonate, a variety of aldehydes can be epoxidized directly with allyl bromide at 50°C under solid-liquid phase transfer condition by use of a catalytic amount of diisobutyl telluride to afford vinyl epoxides in good yields with predominant cis stereoselectivity.
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ABSTRACT
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ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select... more
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
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Tetrahedron Vol. 49. No 31, pp 68216830, 1993 O040O0 93 6.00+.00 1993 per Printed ut Great Britain 8anion Press Ltd REACTIONS 08 DIAOOCOAOUNDS WITH CARBONYL CONBOUNDB MEDIATED BY DIORGANYL TELLURIDE AND CATALYTIC AMOUNT 01 CUI ...
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Research Interests:
ABSTRACT
Electric charging of colloidal particles in nonpolar solvents plays a crucial role for many industrial applications and products, including rubbers, engine oils, toners, or electronic displays. Although disfavored by the low solvent... more
Electric charging of colloidal particles in nonpolar solvents plays a crucial role for many industrial applications and products, including rubbers, engine oils, toners, or electronic displays. Although disfavored by the low solvent permittivity, particle charging can be induced by added surfactants, even nonionic ones, but the underlying mechanism is poorly understood, and neither the magnitude nor the sign of charge can generally be predicted from the particle and surfactant properties. The conclusiveness of scientific studies has been limited partly by a traditional focus on few surfactant types with many differences in their chemical structure and often poorly defined composition. Here we investigate the surface charging of poly(methyl methacrylate) particles dispersed in hexane-based solutions of three purified polyisobutylene succinimide polyamine surfactants with "subtle" structural variations. We precisely vary the surfactant chemistry by replacing only a single el...
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The antiparkinsonian and antidyskinetic profile of two N-methyl-D-aspartate (NMDA) receptor antagonists, a competitive antagonist, (R)-4-oxo-5-phosphononorvaline (MDL 100,453), and a novel noncompetitive allosteric site antagonist,... more
The antiparkinsonian and antidyskinetic profile of two N-methyl-D-aspartate (NMDA) receptor antagonists, a competitive antagonist, (R)-4-oxo-5-phosphononorvaline (MDL 100,453), and a novel noncompetitive allosteric site antagonist, 4-hydroxy-N-[2-(4-hydroxyphenoxy)ethyl]-4-(4-methylbenzyl)piper idi ne (Co 101244/PD 174494), was assessed in six levodopa-treated 1-methyl-4-phenyl-tetrahydropyridine-lesioned parkinsonian monkeys. The effects on motor function of these two drugs, alone and in combination with levodopa, were then correlated with NMDA subtype selectivity and apparent affinity for four diheteromeric NMDA receptor subunit combinations expressed in Xenopus oocytes. MDL 100, 453 (300 mg/kg s.c.) by itself increased global motor activity (p =. 0005 versus vehicle) and administered 15 min after a low dose of levodopa/benserazide s.c., MDL 100,453 (50, 300 mg/kg s.c.) showed dose-dependent potentiation of antiparkinsonian responses and also produced dyskinesias. Following inject...
Research Interests: Pharmacology, Female, Animals, Male, Levodopa, and 4 moreRats, Xenopus laevis, Macaca fascicularis, and Oocytes
The antiparkinsonian and antidyskinetic profile of two N-methyl-D-aspartate (NMDA) receptor antagonists, a competitive antagonist, (R)-4-oxo-5-phosphononorvaline (MDL 100,453), and a novel noncompetitive allosteric site antagonist,... more
The antiparkinsonian and antidyskinetic profile of two N-methyl-D-aspartate (NMDA) receptor antagonists, a competitive antagonist, (R)-4-oxo-5-phosphononorvaline (MDL 100,453), and a novel noncompetitive allosteric site antagonist, 4-hydroxy-N-[2-(4-hydroxyphenoxy)ethyl]-4-(4-methylbenzyl)piper idi ne (Co 101244/PD 174494), was assessed in six levodopa-treated 1-methyl-4-phenyl-tetrahydropyridine-lesioned parkinsonian monkeys. The effects on motor function of these two drugs, alone and in combination with levodopa, were then correlated with NMDA subtype selectivity and apparent affinity for four diheteromeric NMDA receptor subunit combinations expressed in Xenopus oocytes. MDL 100, 453 (300 mg/kg s.c.) by itself increased global motor activity (p =. 0005 versus vehicle) and administered 15 min after a low dose of levodopa/benserazide s.c., MDL 100,453 (50, 300 mg/kg s.c.) showed dose-dependent potentiation of antiparkinsonian responses and also produced dyskinesias. Following inject...
Research Interests: Pharmacology, Female, Animals, Male, Levodopa, and 4 moreRats, Xenopus laevis, Macaca fascicularis, and Oocytes
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Research Interests:
ABSTRACT
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full... more
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ABSTRACT We report an ultra-low-power stacked reflective display with world leading print-like full color. These results were achieved with a novel stacked Electrokinetic Display (EKD) architecture, proprietary electrically addressable... more
ABSTRACT We report an ultra-low-power stacked reflective display with world leading print-like full color. These results were achieved with a novel stacked Electrokinetic Display (EKD) architecture, proprietary electrically addressable inks, high transparency indium-gallium-zinc-oxide (IGZO) thin-film transistor (TFT) backplanes, and an efficient method of grayscale driving.
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ABSTRACT We report an ultra-low-power stacked reflective display with world leading print-like full color. These results were achieved with a novel stacked Electrokinetic Display (EKD) architecture, proprietary electrically addressable... more
ABSTRACT We report an ultra-low-power stacked reflective display with world leading print-like full color. These results were achieved with a novel stacked Electrokinetic Display (EKD) architecture, proprietary electrically addressable inks, high transparency indium-gallium-zinc-oxide (IGZO) thin-film transistor (TFT) backplanes, and an efficient method of grayscale driving.
Research Interests:
A novel architecture and proprietary electronic inks were developed to provide disruptive digital-media solutions based on an electrokinetic technology platform. The flexible reflective electronic media (eMedia) was fabricated by... more
A novel architecture and proprietary electronic inks were developed to provide disruptive digital-media solutions based on an electrokinetic technology platform. The flexible reflective electronic media (eMedia) was fabricated by imprinting three-dimensional microscale ...