2] behaves as a
Lewis acid where the vacant orbital accepts one of three lone pairs on the fluorine atom of the glycosyl fluoride.
Polymerizations were performed in a double wall 2 L steel reactor, which was purged with nitrogen before the addition of organic solvent, metal complex, activators),
Lewis acids or other components.
New stage in living cationic polymerization: An array of effective
Lewis Acid catalysts and fast living polymerization in seconds.
Very often these initiators eliminate the drawbacks presented by the more common protic and
Lewis acid catalysts in that they are chemically well defined and allow a quantitative initiation reaction to proceed without complicated side reactions or the need for cocatalysts and promoters.
The technique uses the
Lewis acid tris(pentafluorophenyl) borane and the Lewis base tetramethylpiperidine that have been modified to be too large to get close enough to form an adduct (Lewis bases, which carry a lone pair of electrons, can bond with
Lewis acids to form molecules called adducts).
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LEWIS ACID AND BRONSTED ACID AS CATALYSTS FOR ORGANIC
Scientists mainly in Japan, but also in China, Singapore, France, Canada, and the US are the authors, with chapters on the many uses of
Lewis acid as a catalyis for organic synthesis including Mg(II), Zn(II), Ca(II), Li(I), Na(I), K(I), Boron(III), Al(III), Ga(III), IN(III), Si(IV), Sn(II & IV), Bismuth(III), and polymer-supported metal
Lewis acids, among others.
Lewis acid catalysts can form beta-ketone polymers with a high selectivity and yields that are too low-less than 65%--to be commercially useful.
Molecular recognition of carbohydrates by zinc porphyrins:
Lewis acid Lewis base combination as a dominant factor for their selectivity.
One of the important features of this methodology is the use of a minimum amount of SbCl3 as an effective
Lewis acid catalyst and the avoidance of hazardous organic solvent.
A negative Huggins interaction parameter and excellent miscibility are expected because that MMA-MAAM copolymer is a Lewis base while MMA-MAA copolymer is a
Lewis acid.
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LEWIS ACID AND BRONSTEAD ACID AS CATALYSTS FOR ORGANIC REACTIONS IN WATER**, Shinelle Caldwell * and Nripendra Bose, Spelman College, Atlanta, GA 30314.
