Alkaline hydrolysis of ethylene phosphate: An <i>ab initio</i> study by supermolecule model and polarizable continuum approach

Xia, Futing; Zhu, Hua

doi:10.1002/jcc.21834

Cited by 10 publications

(4 citation statements)

References 73 publications

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“…In recent years, it has become increasingly popular to model phosphate and other group transfer reactions using a “mixed” solvation model in which the solvent is represented by an implicit model and a number of explicit water molecules (see refs , , , ). Despite the technical limitations of such an approach, this has been shown to be especially useful in reactions involving highly charged species, where the charge on the solute atoms is not properly solvated by the continuum model .…”

Section: Methodsmentioning

confidence: 99%

Resolving Apparent Conflicts between Theoretical and Experimental Models of Phosphate Monoester Hydrolysis

et al. 2014

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Understanding phosphoryl and sulfuryl transfer is central to many biochemical processes. However, despite decades of experimental and computational studies, a consensus concerning the precise mechanistic details of these reactions has yet to be reached. In this work we perform a detailed comparative theoretical study of the hydrolysis of p-nitrophenyl phosphate, methyl phosphate and p-nitrophenyl sulfate, all of which have served as key model systems for understanding phosphoryl and sulfuryl transfer reactions, respectively. We demonstrate the existence of energetically similar but mechanistically distinct possibilities for phosphate monoester hydrolysis. The calculated kinetic isotope effects for p-nitrophenyl phosphate provide a means to discriminate between substrate- and solvent-assisted pathways of phosphate monoester hydrolysis, and show that the solvent-assisted pathway dominates in solution. This preferred mechanism for p-nitrophenyl phosphate hydrolysis is difficult to find computationally due to the limitations of compressing multiple bonding changes onto a 2-dimensional energy surface. This problem is compounded by the need to include implicit solvation to at least microsolvate the system and stabilize the highly charged species. In contrast, methyl phosphate hydrolysis shows a preference for a substrate-assisted mechanism. For p-nitrophenyl sulfate hydrolysis there is only one viable reaction pathway, which is similar to the solvent-assisted pathway for phosphate hydrolysis, and the substrate-assisted pathway is not accessible. Overall, our results provide a unifying mechanistic framework that is consistent with the experimentally measured kinetic isotope effects and reconciles the discrepancies between theoretical and experimental models for these biochemically ubiquitous classes of reaction.

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Section: Methodsmentioning

confidence: 99%

Resolving Apparent Conflicts between Theoretical and Experimental Models of Phosphate Monoester Hydrolysis

et al. 2014

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“…Bendikov et al [107] experimentally and theoretically studied the reactions of EtOEP with different nucleophiles at B3LYP/6-31+G* [40,78,92,93] level of theory, and found that C-O bond cleavage (C attack) was preferable for C, P and sterically hindered O-nucleophiles, while P-O bond cleavage (P attack) was preferable for OH − and OMe − nucleophiles. The latter direction was found to be preferable for MeOEP hydrolysis; ab initio calculations also confirmed this issue [108]. P-O bond cleavage is reaction direction that corresponds to catalytic ROP of ethylene phosphates (Scheme 3b).…”

Section: Tbd Substituted Guanidines and Related Compoundsmentioning

confidence: 82%

DFT Modeling of Organocatalytic Ring-Opening Polymerization of Cyclic Esters: A Crucial Role of Proton Exchange and Hydrogen Bonding

Nifant’ev

Ivchenko

2019

Polymers

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Organocatalysis is highly efficient in the ring-opening polymerization (ROP) of cyclic esters. A variety of initiators broaden the areas of organocatalysis in polymerization of different monomers, such as lactones, cyclic carbonates, lactides or gycolides, ethylene phosphates and phosphonates, and others. The mechanisms of organocatalytic ROP are at least as diverse as the mechanisms of coordination ROP; the study of these mechanisms is critical in ensuring the polymer compositions and architectures. The use of density functional theory (DFT) methods for comparative modeling and visualization of organocatalytic ROP pathways, in line with experimental proof of the structures of the reaction intermediates, make it possible to establish these mechanisms. In the present review, which continues and complements our recent manuscript that focused on DFT modeling of coordination ROP, we summarized the results of DFT modeling of organocatalytic ROP of cyclic esters and some related organocatalytic processes, such as polyester transesterification. 4 of 49 were found to be polymerizable due to strain in the ester group. In addition, the predominance of high-energy coiled conformations in linear homopolymers the formed from PDO, εCL and GL was proportionately less than extended conformations, in comparison to the inactive monomer γBL. However, while the prevalence of coiled conformations over extended conformations was expected for poly(LA), this factor does not affected the reactivity of lactides. Very good agreement between the experimental and calculated data for ROP of GL, l-LA and (R,S)-lactide [47] should be separately noted. 4-(Dimethylamino)pyridine (DMAP) and Related CompoundsDMAP was the first employed organocatalyst in polymer synthesis. In 2001, Nederberg et al. [48] reported the "first organocatalytic living polymerization" (Ð M < 1.2) of L-lactide (l-LA) mediated by DMAP or 4-pyrrolidinopyridine in the presence of ROH initiators. Four years later [49], Feng and Dong reported polymerization of ε-caprolactone (εCL) catalyzed by DMAP in the presence of chitozane as an initiator. Bourissou et al. studied the mechanism of DMAP-catalyzed ROP of l-LA and five-membered lactic O-carboxylic anhydride (lacOCA) [50]. Two possible reaction pathways were analyzed at the B3LYP/6-31G(d) level of theory [39,40,51]; the solvent effect of dichloromethane was taken into account through the PCM/SCRF model [52]. The modeled reaction was the methanolysis of l-LA or lacOCA; alternative nucleophilic/monomer (Scheme 1a) and basic/alcohol (Scheme 1b) activation mechanisms were proposed for these reactions, and then analyzed by DFT optimization of the key reaction intermediates and transition states, if necessary. Scheme 1. Schematic representation of the nucleophilic/monomer (a) and basic/alcohol (b) mechanisms for (Dimethylamino)pyridine (DMAP)-catalyzed methanolysis of l-LA. Author Contributions: Conceptualization, P.I.; Methodology, I.N. and P.I.; Writing-Original draft preparation, P.I.; Writing-Review and editing, I.N. and P.I.; V...

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“…In a word, preliminary results obtained by using implicit models anticipate that solvation plays a minor effect in this process. According to predicted free energy barrier in solution, the classical rate constant at room temperature can be calculated with the Eyring equation

k = (k_{B} T / h) . \exp (- ΔG / RT)

as performed in a few theoretical literature [48, 49]. The rate constants of 2B‐TS1 and 2B‐TS2 are about 1.49 × 10 −11 s −1 and 2.54 s −1 at the M06 method.…”

Section: Resultsmentioning

confidence: 99%

“…Þas performed in a few theoretical literature [48,49]. The rate constants of 2B-TS1 and 2B-TS2 are about 1.49 Â 10 À11 s À1 and 2.54 s À1 at the M06 method.…”

Section: Solvent Effectmentioning

confidence: 99%

Computational study of the alcoholysis for organophosphorus pesticides: The reaction of phoxim with methanol

Chen

Liang

2023

Int J of Quantum Chemistry

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The alcoholysis process for one of organophosphorus pesticides, phoxim, was systematically examined by using the M06-2X/6-311++G(d,p) and MP2/6-311++G (d,p)//M06-2X/6-311++G(d,p) levels. Two possible alcoholysis mechanisms, P-OR1, P-OEt rupture channels together with the concerted and stepwise steps, were theoretically evaluated. The catalytic role of an extra methanol was also simulated.Furthermore, the influence of solvent on water was also taken into consideration for the M06-2X/6-311++G(d,p) level of theory. Our predicted results show convincingly that the P-OEt disintegration pathway is slightly more favorable than the P-OR removal channel. The stepwise pathway is calculated to be more prominent than the concerted one for all reactions. It can be observed that the methanol-assisted alcoholysis is more easier to take place than the direct alcoholysis. Solvent effect does not have remarkable effect on the reaction mechanism.

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Alkaline hydrolysis of ethylene phosphate: An ab initio study by supermolecule model and polarizable continuum approach

Cited by 10 publications

References 73 publications

Resolving Apparent Conflicts between Theoretical and Experimental Models of Phosphate Monoester Hydrolysis

Resolving Apparent Conflicts between Theoretical and Experimental Models of Phosphate Monoester Hydrolysis

DFT Modeling of Organocatalytic Ring-Opening Polymerization of Cyclic Esters: A Crucial Role of Proton Exchange and Hydrogen Bonding

Computational study of the alcoholysis for organophosphorus pesticides: The reaction of phoxim with methanol

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