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Upstream product

• 123-66-0 Ethyl hexanoate 
• 956-75-2 p-nitrophenyl hexanoate 
• 111-26-2 hexan-1-amine 
• 126375-40-4 m-nitrophenyl hexanoate 

Relevant academic research and scientific papers

Direct deamination of primary amines by water to produce alcohols

Just add water! The title reaction is catalyzed by an acridine-based pincer complex (1, see scheme). This one-step transformation uses water as the only reagent in the absence of additional bases, oxidants, or reductants. Cyclization of 1,4-diaminobutane and 1,6-diaminohexane catalyzed by 1 leads to the formation of pyrrolidine and azepane, respectively. Copyright

Polyphenolic Bioprecursors

Cosmetic and therapeutic, in particular dermatological bioprecursors have the formula [A]n—PP—[B]m wherein PP is a polyphenol radical in which each hydroxyl function is protected by a group A or a group B, A is a saturated or unsaturated, substituted or unsubstituted alkyl radical having 1 to 20 carbon atoms which is bonded to the polyphenol, n is an integer not less than 1, and B is a precursor of a biologically active molecule, which is also bonded to the polyphenol, and m is an integer also not less than 1.

A study on a primitive artificial esterase model: Reactivity of a calix[4]resorcinarene bearing carboxyl groups

The host molecule octacarboxymethyl calix[4]resorcinarene 1 catalyses the hydrolysis of substituted phenyl N-methylpyridinium-4-carboxylate esters 3a-f by complexation followed by intracomplex reaction via an anhydride intermediate. The reactivity in the

Effect of heteroatom insertion at the side chain of 5-alkyl-1H-tetrazoles on their properties as catalysts for ester hydrolysis at neutral pH

Herein we introduce tetrazole and its suitably designed derivatives as powerful ester-cleaving reagents. By first performing a detailed ab initio computational study, we found that, in the side chain of 5-alkyl-1H-tetrazoles, introduction of a heteroatom (e.g., N, O, or S at the α-position of the tetrazole ring) raises the charge on the tetrazole nucleus significantly. All calculations have been performed using restricted Hartree-Fock (RHF) and hybrid ab initio/DFT (B3LYP) methods employing 6-31G* and 6-31+G* basis sets. To estimate the nucleophilicity of these reagents, the charges on conjugate bases of various tetrazole derivatives have been calculated using natural population (NBO) analysis in gas phase and in water. Free energy of protonation (fep) of the 1H-tetrazole derivatives (1-7), free energy of solvation, ΔGaq, and the corresponding pKa values have been calculated by self-consistent reaction field (SCRF) methods applying the polarized continuum model (PCM). Since the calculation indicates that incorporation of heteroatom leads to enhanced nucleophilicity in their deprotonated anionic tetrazole forms, a series of 5-substituted 1H-tetrazole derivatives have been synthesized. These compounds indeed catalyze the hydrolysis of p-nitrophenyl diphenyl phosphate (PNPDPP) and p-nitrophenyl hexanoate (PNPH) efficiently in cationic cetyl trimethylammonium bromide (CTABr) micelles at pH 7.0 and 25 °C. The pseudo-first-order rate constants (k obs) were determined for each catalyst against both substrates. The experimental and theoretical results show that, to achieve better k obs values for the cleavage of PNPDPP and PNPH under micellar conditions, charge on the N- atom (nucleophile) of conjugate base is important. Replacing the α-CH2 in alkyl substituent with S (3), NH (4), or O (5) enhances the accumulation of charge on N- in conjugate bases of tetrazoles and subsequently increases their intrinsic nucleophilic reactivity toward hydrolytic reactions. Significantly large rate enhancements were observed for the cleavage of PNPDPP and PNPH at pH 7.0 in the presence of catalytic system 5/CTABr over background (only CTABr). Tetrazole 4 (α-isomer) showed 4-5-fold superior reactivity over 6 (β-isomer) under identical conditions. Natural charges obtained from NBO analysis (B3LYP/ 6-31+G*) are -0.94 and -0.852 on N- in the conjugate bases of 4 and 6, respectively. This also predicts that 4 is a better nucleophile than 6. All the newly synthesized tetrazole derivatives in micellar media display true catalytic properties by cleaving several fold excess of substrates.

The Kinetics of Basic Cleavage of Nitrophenyl Alkanoate Esters by 'Hydroxypropyl-β-cyclodextrin' in Aqueous Solution

The kinetics of cleavage of m- and p-nitrophenyl alakanoates by 'hydroxypropyl-β-cyclodextrin' (Hp-β-CD) in basic aqueous solution vary significantly with the chain length of the esters (C2 to C10).For both series of esters with short chains (C2 to C6) simple saturation kinetics are observed, indicative of 1:1 (ester:CD) binding and reaction of one molecule of ester with one molecule of Hp-β-CD.For longer chains, there is also a cleavage process involving two molecules of Hp-β-CD.This type of behaviour was not found previously for the same esters reacting with α-CD and with β-CD but it has been observed for some carboxynitrophenyl alkanoates.With the longest esters there is also evidence of productive 1:2 (ester:CD) binding.For the 1:1 binding, there is a linear dependence of the strength on acyl chain length and the close similarity of the dissociation constants for the two series of esters implicate inclusion of the alkyl chains of the esters acyl groups.Transition-state binding is more complex: for the meta-nitro isomers aryl-group inclusion appears dominant whereas for the para isomers there seems to be a switch from aryl-group inclusion to acyl-group inclusion, occurring at a chain length of C6-C7.

Lactones. 2. Enthalpies of hydrolysis, reduction, and formation of the C4-C13 monocyclic lactones. Strain energies and conformations

The enthalpies of hydrolysis of the monocyclic lactones from γ-butyrolactone to tridecanolactone were determined calorimetrically, and the acyclic ethyl having the number of atoms were studied in the fashion. The enthalpies of reduction of the lactones to the corresponding α,ω-alkanediols with lithium triethylborohydride also were determined. The enthalpies of formation of the lactones and the ethyl esters were derived from these data. They were converted to values for the gas phase by measuring the enthalpies of vaporization of ethyl esters and of lactones. In the of γ-butyrolactone and δ-valerolactone, the enthalpies of formation were in good accord with the previously reported values determined via combustion calorimetry. The strain energies of the lactones were obtained via isodesmic reactions. Valerolactone had a strain energy of 11 kcal/mol, and the largest strain energy was found with octanolactone (13 kcal/mol). The conformations of γ-butyrolactone and δ-valerolactone were studied via MP2/6-31G* geometry optimizations, and the conformations of the other lactones were studied with use of the molecular mechanics program MM3. The energies of the lactones estimated via molecular mechanics were compared with the experimental results.

Contrasting Behaviors in the Cleavage of Aryl Alkanoates by α- and β-Cyclodextrins in Basic Aqueous Solution

The kinetics of ester cleavage of 4-carboxy-2-nitrophenyl alkanoates (C2, C4, C6, C7, C8) in aqueous base containing α- or β-cyclodextrin (α- or β-CD) indicate that for the three longer esters there are processes involving two CD molecules which are quite distinct: with α-CD a 2:1 binding leads to inhibition; with β-CD a second-order process provides catalysis.