Technical documentation

Perfluoropentaphenylborole: A New Approach to Lewis Acidic, Electron-Deficient Compounds

By: 
Keith Huynh
Joan Vignolle
T. Don Tilley

Zirconocene is the key: A new synthetic method, which utilizes zirconocene-mediated coupling of alkynes, has been developed for the preparation of a new class of highly Lewis acidic boroles (see scheme). Such compounds hold potential for applications in catalysis and the field of electron-deficient organic materials.

Perfluoropentaphenylborole

By: 
Cheng Fan
Warren E. Piers
Masood Parvez

Perfluorination: The fully fluorinated analogue of pentaphenylborole (see structure; B gray, C black, F green) has been prepared using successive transmetallation reactions involving Zr and Sn heterocycles. The highly moisture-sensitive borole is a new member of the perfluoroaryl borane family, a class of antiaromatic compounds of fundamental significance to concepts of aromaticity.

BF3.SiO2: An efficient heterogeneous alternative for regio-chemo and stereoselective claisen-schmidt condensation

By: 
B. Sadeghi
B. F. Mirjalili
M. M. Hashemi

Under solvent free conditions between 40-50 °C, BF3.SiO2, a mild solid acid catalyst, is applied to regio-chemo and stereoselective Claisen-Schmidt condensation. The procedure is very simple and the products are isolated with an easy workup in good to excellent yields.

Adhesive Cyanoacrylate Compositions with Reduced Adhesion to Skin

US4444933
By: 
Peter S. Columbus
John Anderson

A cyanoacrylate-based adhesive composition comprises 55-92% by weight of a 2-cyanoacrylate ester, preferably the ethyl ester, from 40-30% by weight of a vinyl chloride/vinyl acetate copolymer and not more than 25% by weight of a plasticizer (the plasticizer may be omitted entirely). The copolymer is preferably a vinyl chloride/vinyl acetate/maleic acid terpolymer.

Adhesive Cyanoacrylate Compositions with Reduced Adhesion to Skin

US4444933
By: 
Peter S. Columbus
John Anderson

A cyanoacrylate-based adhesive composition comprises 55-92% by weight of a 2-cyanoacrylate ester, preferably the ethyl ester, from 40-30% by weight of a vinyl chloride/vinyl acetate copolymer and not more than 25% by weight of a plasticizer (the plasticizer may be omitted entirely). The copolymer is preferably a vinyl chloride/vinyl acetate/maleic acid terpolymer.

Effect of Derivatives of ß-substituted Methylenemalonic and Acrylic Acids on the Radical Polymerisation of Cyanoacrylate Monomers

By: 
A. M. Vetrova
O. N. Klenovich
M. P. Badryzlova
A. P. Sineokov

Reaction of Trimethylsilyl Sulfate

By: 
Leo H. Sommer
George T. Kerr
Frank C. Whitmore

Sulfonation of Aromatic and Heterocyclic Compounds with Bis(Trimethylsilyl) Sulfate

By: 
M. G. Voronkov
S. V. Korchagin
V. K. Roman
E. A. Maletina

A new sulfonating agent, namely bis(trimethylsilyl) sulfate, was found, which easily sulfonates benzene derivatives that contain substituents of the first type, and also thiophene. Benzene and nitrobenzene do not react with bis (trimethylsilyl) sulfate.

Bis(trimethylsilyl) Sulfate-Silica Catalysed Thioacetalisation of Carbonyl Compounds

By: 
Harish K. Patney

Bis(trimethylsilyl) sulfate-silica has been shown to be an efficient reagent system for promoting thioacetalisation of carbonyl compounds at room temperature.

Reactivity of Bis(trimethylsilyl) Sulfate with Respect to the Surface of Silica

By: 
A. M. Varvarin
L. A. Belyakova
A. V. Simurov
V. A. Tertykh
L. A. Lazukina
V. P. Kukhar

It was established by IR spectroscopy and chemical analysis that bis(trimethylsilyl) sulfate reacts chemically with isolated silanol groups of silica even at room temperature, and is quantitatively chemisorbed at 373 K. Sulfidation of the silica does not occur. Chemisorption of [(CH3)3Si]2SO4 on the surface of silicon(IV) oxide is not complicated by side processes.

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