Functional micellar catalysis. Part 5. Catalysis of activated amide hydrolysis by hydroxy and imidazole functionalized surfactant systems

1982 ◽  
pp. 899 ◽  
Author(s):  
Roberto Fornasier ◽  
Umberto Tonellato
Keyword(s):  
Micellar Catalysis ◽  
Amide Hydrolysis ◽  
Surfactant Systems

scholarly journals Micellar Catalysis of Chemical Reactions by Mixed Surfactant Systems and Gemini Surfactants

2021 ◽  
Vol 33 (7) ◽  
pp. 1471-1480
Author(s):  
Mohammed Hassan ◽  
Sadeq M. Al-Hazmi ◽  
Ibrahim A. Alhagri ◽  
Ahmed N. Alhakimi ◽  
Adnan Dahadha ◽  
...  
Keyword(s):  
Gemini Surfactants ◽  
Chemical Properties ◽  
Catalytic Efficiency ◽  
Micellar Catalysis ◽  
Head Group ◽  
Mixed Surfactant ◽  
Structure Control ◽  
Mixed Surfactant Systems ◽  
Physico Chemical ◽  
Surfactant Systems

Micellar catalysis exhibited by mixed surfactant systems and gemini surfactants was reviewed. The review focused on mixed surfactant systems and tried to correlate the changes in the physico-chemical properties of these systems to the variations of their catalytic activities. Mixed surfactant systems are promising as the catalytic efficiency of some single surfactants was significantly enhanced in the presence of other critically selected surfactants. The selection should consider the charge, size, and structures of the head group as well as an appropriate length of hydrocarbon tail. The overall conclusion has arrived the mixed surfactant systems could be a tool by which the reaction rate can be tuned by changing the composition and/or the components’ structures. The higher catalytic activity of gemini surfactants compared to conventional ones, their facile synthesis and liability for structure control made them of superior choice for micellar catalysis.

Micellar catalysis of organic reactions. 22. A comparison of the basic hydrolysis of benzodiazepinones in the presence of reactive counterion micelles and vesicles

1988 ◽  
Vol 66 (7) ◽  
pp. 1566-1570 ◽  
Author(s):  
Trevor J. Broxton ◽  
Xenia Sango ◽  
Sallyanne Wright
Keyword(s):  
Surfactant Concentration ◽  
Biological Membranes ◽  
Micellar Catalysis ◽  
Organic Reactions ◽  
Conductivity Measurements ◽  
Amide Hydrolysis ◽  
Rate Of Hydrolysis ◽  
Basic Hydrolysis ◽  
Hydrolysis Of ◽  
Good Agreement

The basic hydrolysis of diazepam and several N-alkyl nitrazepam derivatives has been studied in the presence of reactive counterion micelles of cetyltrimethylammonium hydroxide (CTAOH) and vesicles of didodecyldimethylammonium hydroxide (DDAOH). In both surfactants, the rate of hydrolysis of all compounds was found to be dependent on the hydroxide concentration at constant surfactant concentration and this was interpreted as evidence for initial amide hydrolysis. The hydrolysis in CTAOH was inhibited by added salts in the order Br− < NO3− < SO42−. At concentrations above 3 mM surfactant, the rate of hydrolysis of each compound was similar in CTAOH and in DDAOH. At lower concentrations of CTAOH, however, the rate of hydrolysis was significantly lower than that in DDAOH. On the basis of this evidence, it was concluded that the cmc of CTAOH was between 2–3 mM, which is in good agreement with the value of 1.8 mM obtained by Zana from conductivity measurements. For diazepam, a mechanistic change is indicated on transfer from water to either micelles or vesicles and since vesicles are considered good models of biological membranes, this suggests that conclusions concerning the bioavailability of diazepam should not be based on studies in water but rather on studies in either micelles or vesicles.

Micellar catalysis of organic reactions. XIV. Hydrolysis of some 1,4-Benzodiazepin-2-one drugs in acidic solution

1984 ◽  
Vol 37 (9) ◽  
pp. 1895 ◽  
Author(s):  
TJ Broxton ◽  
T Ryan ◽  
SR Morrison
Keyword(s):  
Acid Concentration ◽  
Acidic Solution ◽  
Sodium Dodecyl ◽  
Kinetic Studies ◽  
Micellar Catalysis ◽  
Amide Bond ◽  
First Order ◽  
Amide Hydrolysis ◽  
Hydrolysis Of ◽  
Azomethine Bond

Kinetic studies of the acidic hydrolysis of diazepam and nitrazepam were carried out in the presence of micelles of sodium dodecyl sulfate (sds). The hydrolysis of diazepam was shown to occur with biphasic kinetics. This is consistent with initial hydrolysis of the azomethine bond followed by very slow hydrolysis of the amide bond as found for hydrolysis in aqueous solution. Nitrazepam, however, was found to decompose with monophasic kinetics consistent with initial amide hydrolysis. Reactions involving the hydrolysis of the azomethine bond were shown to be independent of acid concentration and subject to inhibition by micelles of sds. Reactions involving amide hydrolysis were shown to be first order in acid concentration and subject to micellar catalysis. The mechanistic change for the hydrolysis of nitrazepam on transfer from water (initial azomethine cleavage) to micelles of sds (initial amide cleavage), was presumably the result of the inhibition of azomethine hydrolysis and the catalysis of amide hydrolysis by the micelles.

Micellar Catalysis of Organic Reactions. XXXVIII A Study of the Catalytic Effect of Micelles of 3-Hydroxymethyl-1-tetradecylpyridinium Bromide on Amide Hydrolysis and Nucleophilic Aromatic Substitution

1998 ◽  
Vol 51 (7) ◽  
pp. 541 ◽  
Author(s):  
Trevor J. Broxton
Keyword(s):  
Catalytic Effect ◽  
Micellar Catalysis ◽  
Aryl Halides ◽  
Organic Reactions ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Rate Determining Step ◽  
Amide Hydrolysis

The preparation of 3-hydroxymethyl-1-tetradecylpyridinium bromide and its use as a catalyst of nucleophilic aromatic substitution and also amide hydrolysis are reported. It was found that the hydroxydehalogenation of nitro-activated aryl halides was much faster in these micelles than in the presence of cetyl(2-hydroxyethyl)dimethylammonium bromide. It was concluded that the increased catalysis of nucleophilic aromatic substitution by this micelle was due to a faster decomposition of the aryl micellar ether which must occur before the phenolate product is released. No such difference in the two micelles was found for amide or thioamide hydrolysis since in these reactions the product amine is produced in the first step of the reaction and decomposition of the acylated micelle is not required in the rate-determining step of the reaction.

Determination of 1,1-dimethylhydrazine (UDMH) in water by HPLC-UV using micellar catalysis for preparation of the derivatives

2020 ◽  
Vol 86 (9) ◽  
pp. 14-23
Author(s):  
Yu. V. Timchenko ◽  
I. V. Belikova ◽  
A. D. Smolenkov ◽  
A. V. Pirogov ◽  
O. A. Shpigun
Keyword(s):  
Micellar Catalysis
Sign in / Sign up

Export Citation Format

Share Document