Grafting polyzwitterions onto polyamide by click chemistry and nucleophilic substitution on nitrogen: A novel approach to enhance membrane fouling resistance

Dess−Martin Periodinane Oxidation of Alcohols in the Presence of Stabilized Phosphorus Ylides: A Convenient Method for the Homologation of Alcohols via Unstable Aldehydes

Amidines and guanidines are important functional groups in molecular recognition and host-guest chemistry. Here it is shown that lipophilic amidinium ions catalyze a cycloaddition reaction representing the key step of the Quinkert-Dane estrone synthesis. Hydrogen-bond-mediated association with the organic cation leads to an electrophilic activation of the dienophile and to enhanced rates of the Diels-Alder reaction. The observed effects are similar to those expected from mild Lewis acids. In competition experiments, amidinium catalysis favors the reaction of the less electron deficient dienophile.

Catalysis of a Diels−Alder Reaction by Amidinium Ions

Colorimetric sensors for detection of an analyte are disclosed. Methods of using the colorimetric sensor and a kit for the colorimetric detection of an analyte are also disclosed.

Colorimetric sensors constructed of diacetylene materials

Organic reactions under high pressure. 1v. the dimerization of isoprene

The structure of the cyclic product formed by the action of boron trifluoride on acrolein diethyl acetal is proved This results confirm the scheme proposed earlier for the trimerization of the acetal

Chemistry of acetals

1.

A study has been made of the diene condensation of 1-vinylcyclohexene (I) with citraconic anhydride (II), and it has been shown that in this reaction the ortho and meta adducts (III) and (IV) are formed in the proportions of 5 : 1 and in an overall yield of 92%. Hydrolysis of the cis anhydrides (III) and (IV) yielded the corresponding cis-1,2,3,5,6,7,8,8a-octahydromethyl-1,2-naphthalenedicarboxylic acids (V) and (VI), and the structures and spartial configurations of these have been proved.




2.

The unsaturated cis anhydrides (III) and (IV), and also the corresponding cis acids (V) and (VI), are readily hydrogenated in a sterically selective manner at a platinum catalyst into the corresponding saturated compounds (VII), (VIII), (XV), and (XVI), the direction of the reaction being determined by the screening effect of the cis substituents at (C-1)-(C-8a) on the double bond.




3.

By the isomerization of the cis diesters (IX), (X), and (XVII) with the aid of sodium methoxide, the corresponding trans acids (XI), (XII), and (XIX) have been obtained in good yield, and this reaction may provide a convenient method for their synthesis. The hydrogenation of the unsaturated trans acid (XIX), unlike that of the isometric trans acid (XI), is not sterically selective.




4.

By treatment with acetyl chloride in a mixture of acetic anhydride and acetic acid, the cis diesters (IX) and (XVII) have been caused to undergo isomerization with displacement of the double bond to give the cis diesters (XIII) and (XXI). Further isomerization of these in presence of sodium methoxide yields the trans acids (XIV) and (XXII), which have an inter-ring double bond. These acids, as also the esters (XIII) and (XXI), cannot be hydrogenated over a platinum catalyst under the usual conditions.




5.

Irrespective of the temperature (within the range 100–230°), the condensation of 1-vinylcycohexene with citraconic anhydride proceeds by exo-addition.

Stereochemistry of cyclic compounds Communication 4. Condensation of 1-vinylcyclohexene with citraconic anhydride

1.

Three ways of synthesizing polyenic dicarboxylic acids having even numbers of double bonds are proposed.




2.

A new method of synthesizing corticrocin diethyl ester is described.




3.

The difficulty with which the cis bond in 6-cis-corticrocin diethyl ester is isomerized is pointed out.

Chemistry of polyenic and polyacetylenic compounds communication 8. Methods of synthesizing polyenic dicarboxylic acids having even numbers of double bonds and also polyenynic dicarboxylic acids

With the aid of the Mannich reaction, from diacetylenic alcohols and 1,3-alkadiynes, various types of dialkylamino derivatives of 1,3-diynes were synthesized.

Chemistry of polyenic and polyynic compounds Communication 13. Synthesis of dialkylamino derivatives of 1,3-diynes

1.

Replacement of the nitrogen-attached hydrogen of octahydro-4(1H)-quinolone by methyl does not affect the preferential stability of the trans-fusion of the rings.




2.

The configurations of the three isomers of 1-methyl-4-phenyldecahydro-4-qiuinolinol with respect to the fusion of the rings were determined, and an investigation was made of the stereochemistry of some nucleophilicaddition reactions at the carbonyl group in the octahydro-4(1H)-quinolone series in its dependence on substitution on the nitrogen.

V. F. Kucherov

Papers

Chemistry of acetals

Stereochemistry of cyclic compounds Communication 4. Condensation of 1-vinylcyclohexene with citraconic anhydride

Chemistry of polyenic and polyacetylenic compounds communication 8. Methods of synthesizing polyenic dicarboxylic acids having even numbers of double bonds and also polyenynic dicarboxylic acids

Chemistry of polyenic and polyynic compounds Communication 13. Synthesis of dialkylamino derivatives of 1,3-diynes

Stereochmeistry of heterocyclic compounds