2697-50-9Relevant articles and documents
Foldamers as reactive sieves: Reactivity as a probe of conformational flexibility
Smaldone, Ronald A.,Moore, Jeffrey S.
, p. 5444 - 5450 (2008/02/04)
A series of m-phenyleneethynylene (mPE) oligomers modified with a dimethylaminopyridine (DMAP) unit were treated with methyl sulfonates of varying sizes and shapes, and the relative reactivities were measured by UV spectrophotometry. Using a small-molecule DMAP analogue as a reference, each of the methyl sulfonates was shown to react at nearly identical rate. In great contrast, oligomers that are long enough to fold, and hence capable of binding the methyl sulfonate, experience rate enhancements of 18-1600-fold relative to that of the small-molecule analogue, depending on the type of alkyl chain attached to the guest. Three different oligomer lengths were studied, with the longest oligomers exhibiting the fastest rate and greatest substrate specificity. Even large, bulky guests show slightly enhanced methylation rates compared to that with the reference DMAP, which suggests a dynamic nature to the oligomer's binding cavity. Several mechanistic models to describe this behavior are discussed.
Process for preparation of oxyglutaric acid ester derivatives
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, (2008/06/13)
A process for preparing an oxyglutaric acid ester derivative of the formula: STR1 in which each of R1 and R2 is C1-5 alkoxy, C1-7 aralkyloxy, C7-9 halogenated aralkyloxy or phenyl, R4 is a hydroxyl-protecting group, and R5 is C1-10 alkyl which may have a substituent, comprises the steps of reacting a methyl phosphonate derivative or methyl phosphine oxide derivative with an oxyglutaric acid mono-ester to give a reaction product which comprises an oxyglutaric acid derivative having a phosphorus-containing group and a pentenedioic acid mono-ester (by-product), removing the pendenedioic acid mono-ester from the reaction product to isolate the oxyglutaric acid derivative, and converting the isolated oxyglutaric acid derivative into the oxyglutaric acid ester derivative. A process for obtaining an optically active oxyglutaric acid ester derivative is also disclosed.
ALKANESULFONYLATION REACTIONS. I. CHARACTERISTICS OF THE ALKANESULFONYLATION OF PHENOL-d1 AND METHANOL-d1 CATALYZED BY TERTIARY AMINES
Skrypnik, Yu. G.,Bezrodnyi, V. P.
, p. 511 - 515 (2007/10/02)
The products from alkanesulfonylation of phenol-d1 and methanol-d1 catalyzed by tertiary amines, which occurs in at least three competing directions (nucleophilic and general base catalysis and a sulfene mechanism), were investigated.The degree of realization of the sulfene mechanism was determined from the content of the ester-d1, and its dependence on the structure of the catalysis, the substrate, the reagent, and the nature of the solvent was investigated.It was shown that the fraction of the ester-d1 decreases with decrease in the basicity and steric accessibility of the tertiary amine.Investigation of the effect of the structure of the sulfonyl chloride shows that the fraction of the sulfene mechanism decreases with decrease in the acidity of the α-protons and their steric accessibility.It was shown that the most favorable conditions for realization of the sulfene mechanism are created in benzene.
