1
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Cabello MC, Bartoloni FH, Baader WJ. An Update on General Chemiexcitation Mechanisms in Cyclic Organic Peroxide Decomposition and the Chemiluminescent Peroxyoxalate Reaction in Aqueous Media. Photochem Photobiol 2022; 99:235-250. [PMID: 35837818 DOI: 10.1111/php.13673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 07/12/2022] [Indexed: 11/29/2022]
Abstract
Four-membered ring peroxides are intimately linked to chemiluminescence and bioluminescence transformations, as high-energy intermediates responsible for electronically excited state formation. The synthesis of 1,2-dioxetanes and 1,2-dioxetanones enabled mechanistic studies on their decomposition occurring with the formation of electronically excited carbonyl products in the singlet or triplet state. The third member of this family, 1,2-dioxetanedione, has been postulated as the intermediate in the peroxyoxalate reaction, recently confirmed by kinetic studies on peroxalic acid derivatives. Several general chemiexcitation mechanisms have been proposed as model systems for the chemiexcitation step in efficient bioluminescence and chemiluminescence transformations. In this review article, we discuss the validity and efficiency of the most important chemiexcitation mechanisms, extended to aqueous media, where the efficiency is known to be drastically reduced, specifically in the peroxyoxalate reaction, highly efficient in anhydrous environment, but much less efficient in aqueous media. Mechanistic studies of this reaction will be discussed in diverse aqueous environments, with special attention to the catalysis involved in the thermal reaction leading to the formation of the high-energy intermediate and to the chemiexcitation mechanism, as well as emission quantum yields. Finally, several recent analytical and bioanalytical applications of the peroxyoxalate reaction in aqueous media will be given.
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Affiliation(s)
- Maidileyvis C Cabello
- Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Fernando H Bartoloni
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Santo André, Brazil
| | - Wilhelm J Baader
- Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
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2
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D’Souza MJ, Kevill DN. Mechanistic studies of the solvolysis of alkanesulfonyl and arenesulfonyl halides. Beilstein J Org Chem 2022; 18:120-132. [PMID: 35116082 PMCID: PMC8787350 DOI: 10.3762/bjoc.18.13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 12/01/2021] [Indexed: 11/23/2022] Open
Abstract
There have been several studies on the solvolysis mechanisms for alkanesulfonyl chlorides (RSO2Cl) and arenesulfonyl chlorides (ArSO2Cl). The earlier of these studies were reviewed a little over thirty years ago by Gordon, Maskill and Ruasse (Chem. Soc. Rev. 1989, 18, 123-151) in a contribution entitled "Sulfonyl Transfer Reactions". The present review will emphasize more recent contributions and, in particular, the application of the extended Grunwald-Winstein equation and kinetic solvent isotope effects to the solvolysis reactions. There is also an appreciable number of reports concerning the corresponding anhydrides with the chloride leaving group replaced by the appropriate sulfonate leaving group, concerning sulfamoyl chlorides (ZZ'NSO2Cl) with Z and Z' being alkyl or aryl and concerning the solvolysis of chlorosulfate esters (alkoxy- or aryloxysulfonyl chlorides), with the structures ROSO2Cl or ArOSO2Cl. The solvolyses of these additional types of sulfur(VI) substrates will be the topics of a future review.
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Affiliation(s)
- Malcolm J D’Souza
- Delaware Environmental Institute, University of Delaware, 221 Academy Street, Newark, Delaware 19716-5804, USA
| | - Dennis N Kevill
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois 60115-2862, USA
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3
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Soares AR, Reis RA, Melo DU, Boaro A, Bartoloni FH. Better late than never! Transition state character involved in the neutral solvolysis of an oxalic ester determined by the ionizing power of ethanol/water and methanol/water mixtures. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.113800] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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4
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The Influence of a Terminal Chlorine Substituent on the Kinetics and the Mechanism of the Solvolyses of n-Alkyl Chloroformates in Hydroxylic Solvents. Int J Mol Sci 2020; 21:ijms21124387. [PMID: 32575637 PMCID: PMC7353074 DOI: 10.3390/ijms21124387] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/10/2020] [Accepted: 06/18/2020] [Indexed: 11/18/2022] Open
Abstract
A previous study of the effect of a 2-chloro substituent on the rates and the mechanisms of the solvolysis of ethyl chloroformate is extended to the effect of a 3-chloro substituent on the previously studied solvolysis of propyl chloroformate and to the effect of a 4-chloro substituent on the here reported rates of solvolysis of butyl chloroformate. In each comparison, the influence of the chloro substituent is shown to be nicely consistent with the proposal, largely based on the application of the extended Grunwald–Winstein equation, of an addition-elimination mechanism for solvolysis in the solvents of only modest solvent ionizing power, which changes over to an ionization mechanism for solvents of relatively high ionizing power and low nucleophilicity, such as aqueous fluoroalcohols with an appreciable fluoroalcohol content.
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5
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Kevill DN, Kim CB, D'Souza MJ. Correlation of the rates of solvolysis of α-bromoisobutyrophenone using both simple and extended forms of the Grunwald-Winstein equation and the application of correlation analysis to related studies. EUROPEAN JOURNAL OF CHEMISTRY (PRINT) 2018; 9:1-6. [PMID: 29682397 PMCID: PMC5909717 DOI: 10.5155/eurjchem.9.1.1-6.1680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 01/26/2018] [Accepted: 01/26/2018] [Indexed: 06/08/2023]
Abstract
A Grunwald-Winstein treatment of the specific rates of solvolysis of α-bromoisobutyrophenone in 100% methanol and in several aqueous ethanol, methanol, acetone, 2,2,2-trifluoroethanol (TFE), and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) mixtures gives a good logarithmic correlation against a linear combination of NT (solvent nucleophilicity) and YBr (solvent ionizing power) values. The l and m sensitivity values are compared to those previously reported for α-bromoacetophenone and to those obtained from parallel treatments of literature specific rate values for the solvolyses of several tertiary mesylates containing a C(=O)R group attached at the α-carbon. Kinetic data obtained earlier by Pasto and Sevenair for the solvolyses of the same substrate in 75% aqueous ethanol (by weight) in the presence of silver perchlorate and perchloric acid are analyzed using multiple regression analysis.
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Affiliation(s)
- Dennis Neil Kevill
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois 60115-2862, USA
| | - Chang-Bae Kim
- Department of Chemistry, Dan-Kook University, Hannam-dong, Yongsan-gu, Seoul 140-714, Korea
| | - Malcolm John D'Souza
- Department of Chemistry, Wesley College, 120 North State Street, Dover, Delaware 19901-3875, USA
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6
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Choi H, Koo IS. Mechanistic Study of the Solvolysis of Piperidine-1-sulfonyl chloride in Binary Solvent Mixtures. B KOREAN CHEM SOC 2017. [DOI: 10.1002/bkcs.11217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Hojune Choi
- Department of Chemistry Education and Research Instituted of Natural Science; Gyeongsang National University; Jinju 52828 Korea
| | - In Sun Koo
- Department of Chemistry Education and Research Instituted of Natural Science; Gyeongsang National University; Jinju 52828 Korea
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7
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Iazykov M, Canle M, Santaballa JA, Rublova L. Propanolysis of arenesulfonyl chlorides: Nucleophilic substitution at sulfonyl sulfur. J PHYS ORG CHEM 2017. [DOI: 10.1002/poc.3753] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Mykyta Iazykov
- Department of General Chemistry, Faculty of Ecology and Chemical Technology; Donetsk National Technical University; Donetsk Ukraine
- Department of Chemistry, Faculty of Sciences and CICA; Universidade da Coruña, Chemical Reactivity and Photoreactivity Group; A Coruña Spain
| | - Moisés Canle
- Department of Chemistry, Faculty of Sciences and CICA; Universidade da Coruña, Chemical Reactivity and Photoreactivity Group; A Coruña Spain
| | - J. Arturo Santaballa
- Department of Chemistry, Faculty of Sciences and CICA; Universidade da Coruña, Chemical Reactivity and Photoreactivity Group; A Coruña Spain
| | - Ludmila Rublova
- Department of General Chemistry, Faculty of Ecology and Chemical Technology; Donetsk National Technical University; Donetsk Ukraine
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8
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Kevill DN, Ryu ZH, D'Souza MJ. Correlation analysis of the rates of solvolysis of 4-bromopiperidine: a reaction following a Grob fragmentation pathway. EUROPEAN JOURNAL OF CHEMISTRY (PRINT) 2017; 8:162-167. [PMID: 28729923 PMCID: PMC5515489 DOI: 10.5155/eurjchem.8.2.162-167.1566] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A Grunwald-Winstein treatment of the specific rates of solvolysis of 4-bromopiperidine gives for aqueous ethanol, methanol, acetone, and dioxane a very good logarithmic correlation against the YBr solvent ionizing power values with a slope (m value) of 0.46±0.02, consistent with the operation of a synchronous Grob fragmentation mechanism. When the organic component of the solvent is 2,2,2-trifluoroethanol (TFE), the data points show a negative deviation, consistent with an appreciable deactivating interaction of the acidic TFE component of the solvent with the lone-pair of electrons present on the nitrogen.
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Affiliation(s)
- Dennis Neil Kevill
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois 60115-2862, USA
| | - Zoon Ha Ryu
- Department of Chemistry, Dong-Eui University, 995 Eomgwango, Busan-Jin-Gu, Busan 614-714, Republic of Korea
| | - Malcolm John D'Souza
- Department of Chemistry, Wesley College, 120 North State Street, Dover, Delaware 19901-3875, USA
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9
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Iazykov M, Rublova L, Canle L. M, Santaballa JA. Solvent network at the transition state in the solvolysis of hindered sulfonyl compounds. J PHYS ORG CHEM 2017. [DOI: 10.1002/poc.3588] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Mykyta Iazykov
- Department of General Chemistry, Faculty of Ecology and Chemical Technology; Donetsk National Technical University; ave Bogdana Khmelnitskogo 106 83015 Donetsk Ukraine
- Chemical Reactivity and Photoreactivity Group, Department of Physical Chemistry and Chemical Engineering, Faculty of Sciences and CICA; University of A Coruña; E-15071 A Coruña Spain
| | - Ludmila Rublova
- Department of General Chemistry, Faculty of Ecology and Chemical Technology; Donetsk National Technical University; ave Bogdana Khmelnitskogo 106 83015 Donetsk Ukraine
| | - Moisés Canle L.
- Chemical Reactivity and Photoreactivity Group, Department of Physical Chemistry and Chemical Engineering, Faculty of Sciences and CICA; University of A Coruña; E-15071 A Coruña Spain
| | - J. Arturo Santaballa
- Chemical Reactivity and Photoreactivity Group, Department of Physical Chemistry and Chemical Engineering, Faculty of Sciences and CICA; University of A Coruña; E-15071 A Coruña Spain
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10
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Bentley TW, Choi H, Koo IS, Kevill DN. Positioning solvolyses within the S N2-S N1 and S N3-S N2 spectrum of reaction mechanisms. J PHYS ORG CHEM 2017. [DOI: 10.1002/poc.3585] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- T. W. Bentley
- Chemistry Unit, Grove Building, College of Medicine; Swansea University; Swansea SA2 8PP UK
| | - Hojune Choi
- Department of Chemical Education and Research Institute of Natural Science; Gyeongsang National University; Jinju 660-701 Korea
| | - In Sun Koo
- Department of Chemical Education and Research Institute of Natural Science; Gyeongsang National University; Jinju 660-701 Korea
| | - Dennis N. Kevill
- Department of Chemistry and Biochemistry; Northern Illinois University; DeKalb IL 60115-2862 USA
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11
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Carpenter BK, Harvey JN, Orr-Ewing AJ. The Study of Reactive Intermediates in Condensed Phases. J Am Chem Soc 2016; 138:4695-705. [DOI: 10.1021/jacs.6b01761] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Barry K. Carpenter
- School
of Chemistry, Cardiff University, Park Place, Cardiff CF10 3AT, U.K
| | - Jeremy N. Harvey
- Department
of Chemistry, KU Leuven, Celestijnen Laan 200F, B-3001 Heverlee, Belgium
| | - Andrew J. Orr-Ewing
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
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12
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Ryu ZH, Park KH. Mechanistic Analysis of 4-Methylthiobenzoyl Chloride in Solvolysis. B KOREAN CHEM SOC 2016. [DOI: 10.1002/bkcs.10726] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Zoon-Ha Ryu
- Department of Chemistry; Dongeui University; Busan 47340 Korea
| | - Kyoung-Ho Park
- Department of Applied Chemistry; Hanyang University; Ansan 15588 Korea
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13
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D'Souza MJ, Kevill DN. Mechanistic Studies of the Solvolyses of Carbamoyl Chlorides and Related Reactions. Int J Mol Sci 2016; 17:E111. [PMID: 26784185 PMCID: PMC4730352 DOI: 10.3390/ijms17010111] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Revised: 12/07/2015] [Accepted: 12/21/2015] [Indexed: 01/21/2023] Open
Abstract
Carbamoyl chlorides are important intermediates, both in the research laboratory and in industrial scale syntheses. The most studied and used are the disubstituted derivatives, incorporating either aryl or alkyl groups (Ar2NCOCl or R2NCOCl). Sometimes, the groups are tied back to give a ring and piperidino- and morpholino-derivatives are commonly encountered. Some studies have been made with two different groups attached. Solvolyses tend to occur at the carbonyl carbon, with replacement of the chloride ion. Studies of both rate and products are reviewed and the solvolysis reactions are usually SN1, although addition of an amine leads to a superimposable bimolecular component. Many of the studies under solvolytic conditions include the application of the extended Grunwald-Winstein equation. The monosubstituted derivatives (ArNHCOCl or RNHCOCl) are less studied. They are readily prepared by the addition of HCl to an isocyanate. In acetonitrile, they decompose to set up and reach equilibrium with the isocyanate (ArNCO or RNCO) and HCl. Considering that the structurally related formyl chloride (HOCOCl) is highly unstable (with formation of HCl + CO2), the unsubstituted carbamoyl chloride (H2NCOCl) is remarkably stable. Recommended synthetic procedures require it to survive reaction temperatures in the 300-400 °C range. There has been very little study of its reactions.
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Affiliation(s)
| | - Dennis N Kevill
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL 60115-2862, USA.
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14
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Kim YH, Choi H, Koo IS, Koh HJ. Studies of Solvolyses of 1,4-Benzodioxan-6-Sulfonyl Chloride by Extended Grunwald-Winstein Equation. B KOREAN CHEM SOC 2015. [DOI: 10.1002/bkcs.10573] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Yeon Hak Kim
- Department of Chemistry Education and Research Institute of Natural Science; Gyeongsang National University; Jinju 660-701 Korea
| | - Hojune Choi
- Department of Chemistry Education and Research Institute of Natural Science; Gyeongsang National University; Jinju 660-701 Korea
| | - In Sun Koo
- Department of Chemistry Education and Research Institute of Natural Science; Gyeongsang National University; Jinju 660-701 Korea
| | - Han Joong Koh
- Department of Science Education; Jeonju National University of Education; Jeonju 560-757 Korea
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Kevill DN, Ryu ZH. Correlation of the Rates of Solvolysis of 2,1-Benzoxathiol-3-One-1, 1-dioxide (2-Sulfobenzoic Acid Cyclic Anhydride). JOURNAL OF CHEMICAL RESEARCH 2015. [DOI: 10.3184/174751915x14412072517781] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Solvolysis of acyclic mixed carboxylic–sulfonic anhydrides in hydroxylic solvents is known to involve displacement at the carbonyl carbon to produce a carboxylic acid (water as the nucleophile) and/or an ester (alcohol as the nucleophile) plus the anion of the sulfonic acid. Parallel solvolyses of the cyclic mixed anhydride 2-sulfobenzoic anhydride (structurally similar to phthalic anhydride but with one carbonyl group replaced by a sulfonyl group) involve expulsion from the carbonyl carbon of a sulfonate anion that remains attached as an ortho-substituent in the benzoic acid and/or benzoate ester produced. This complicates the choice of a solvent-ionising-power scale for use in an extended Grunwald–Winstein equation treatment. The YOTs scale, previously recommended as a good general purpose scale, is chosen and used in conjunction with the NT solvent nucleophilicity scale. An acceptable correlation is obtained, which is improved when the two solvents rich in the highly ionising 1,1,1,3,3,3-hexafluoro-2-propanol are excluded. As the solvent is varied, the sensitivities to the changes induced in the two scales are low, consistent with an early transition state, but their ratio has a value which is typical for a pathway involving addition–elimination, with addition rate-determining. Earlier reports, supporting aspects of the proposed mechanism, are reviewed.
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Affiliation(s)
- Dennis N. Kevill
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois 60115-2862, USA
| | - Zoon Ha Ryu
- Department of Chemistry, Dong-Eui University, 995 Eomgwango, Busan-Jin-Gu, Busan 614-714, Republic of Korea
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Bentley TW. Calculated third order rate constants for interpreting the mechanisms of hydrolyses of chloroformates, carboxylic Acid halides, sulfonyl chlorides and phosphorochloridates. Int J Mol Sci 2015; 16:10601-23. [PMID: 26006228 PMCID: PMC4463664 DOI: 10.3390/ijms160510601] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 04/29/2015] [Accepted: 04/30/2015] [Indexed: 11/30/2022] Open
Abstract
Hydrolyses of acid derivatives (e.g., carboxylic acid chlorides and fluorides, fluoro- and chloroformates, sulfonyl chlorides, phosphorochloridates, anhydrides) exhibit pseudo-first order kinetics. Reaction mechanisms vary from those involving a cationic intermediate (SN1) to concerted SN2 processes, and further to third order reactions, in which one solvent molecule acts as the attacking nucleophile and a second molecule acts as a general base catalyst. A unified framework is discussed, in which there are two reaction channels—an SN1-SN2 spectrum and an SN2-SN3 spectrum. Third order rate constants (k3) are calculated for solvolytic reactions in a wide range of compositions of acetone-water mixtures, and are shown to be either approximately constant or correlated with the Grunwald-Winstein Y parameter. These data and kinetic solvent isotope effects, provide the experimental evidence for the SN2-SN3 spectrum (e.g., for chloro- and fluoroformates, chloroacetyl chloride, p-nitrobenzoyl p-toluenesulfonate, sulfonyl chlorides). Deviations from linearity lead to U- or V-shaped plots, which assist in the identification of the point at which the reaction channel changes from SN2-SN3 to SN1-SN2 (e.g., for benzoyl chloride).
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Affiliation(s)
- T William Bentley
- Chemistry Unit, Grove Building, School of Medicine, Swansea University, Swansea SA2 8PP, Wales, UK.
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17
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D'Souza MJ, Deol JK, Pavey MT, Kevill DN. Statistical Methods for the Investigation of Solvolysis Mechanisms Illustrated by the Chlorides of the Carbomethoxy Protecting Groups NVOC and FMOC. JOURNAL OF ANALYTICAL METHODS IN CHEMISTRY 2015; 2015:941638. [PMID: 25767738 PMCID: PMC4342068 DOI: 10.1155/2015/941638] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 11/20/2014] [Accepted: 11/24/2014] [Indexed: 06/04/2023]
Abstract
The solvolysis of 4,5-dimethoxy-2-nitrobenzyl chloroformate (NVOC-Cl, 1) is followed at 25.0°C in twenty hydroxylic solvents. A comparison with previously published rates for benzyl chloroformate and p-nitrobenzyl chloroformate indicates that the inductive effect of the nitro and the two methoxy groups strongly influences the rate of reaction. For 1, the specific rates of solvolysis are correlated using an extended Grunwald-Winstein (G-W) treatment. A direct comparison with the data for phenyl chloroformate (PhOCOCl) in identical solvents strongly suggests that the addition step within an addition-elimination mechanism is rate-determining for both substrates. A reevaluation of the kinetic data for 9-fluorenylmethyl chloroformate (FMOC-Cl, 2) involves a correlation of log(k/k o )2 versus log(k/k o )PhOCOCl. In this plot, deviations were observed in solvents rich in a hydrogen-bonding fluoroalcohol component. Omitting the aqueous fluoroalcohol rate measurements for 2 in an analysis using the extended G-W equation suggested the occurrence of dual pathways differing in the dependences upon the ionizing power and nucleophilicity of the solvent. In addition, the fluorenyl ring is rotated out of the plane containing the ether oxygen and, as a result, PhOCOCl is found to solvolyze 20 times faster than 2 in ethanol and methanol.
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Affiliation(s)
- Malcolm J. D'Souza
- Department of Chemistry, Wesley College, 120 N. State Street, Dover, DE 19901-3875, USA
| | - Jasbir K. Deol
- Department of Chemistry, Wesley College, 120 N. State Street, Dover, DE 19901-3875, USA
| | - Maryeah T. Pavey
- Department of Chemistry, Wesley College, 120 N. State Street, Dover, DE 19901-3875, USA
| | - Dennis N. Kevill
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL 60115-2862, USA
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18
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Influence of sulfur for oxygen substitution in the solvolytic reactions of chloroformate esters and related compounds. Int J Mol Sci 2014; 15:18310-32. [PMID: 25310653 PMCID: PMC4227217 DOI: 10.3390/ijms151018310] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 09/22/2014] [Accepted: 09/29/2014] [Indexed: 11/17/2022] Open
Abstract
The replacement of oxygen within a chloroformate ester (ROCOCl) by sulfur can lead to a chlorothioformate (RSCOCl), a chlorothionoformate (ROCSCl), or a chlorodithioformate (RSCSCl). Phenyl chloroformate (PhOCOCl) reacts over the full range of solvents usually included in Grunwald-Winstein equation studies of solvolysis by an addition-elimination (A-E) pathway. At the other extreme, phenyl chlorodithioformate (PhSCSCl) reacts across the range by an ionization pathway. The phenyl chlorothioformate (PhSCOCl) and phenyl chlorothionoformate (PhOCSCl) react at remarkably similar rates in a given solvent and there is a dichotomy of behavior with the A-E pathway favored in solvents such as ethanol-water and the ionization mechanism favored in aqueous solvents rich in fluoroalcohol. Alkyl esters behave similarly but with increased tendency to ionization as the alkyl group goes from 1° to 2° to 3°. N,N-Disubstituted carbamoyl halides favor the ionization pathway as do also the considerably faster reacting thiocarbamoyl chlorides. The tendency towards ionization increases as, within the three contributing structures of the resonance hybrid for the formed cation, the atoms carrying positive charge (other than the central carbon) change from oxygen to sulfur to nitrogen, consistent with the relative stabilities of species with positive charge on these atoms.
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Kevill DN, Ryu ZH. Reaction Mechanism Studies Involving the Correlation of the Rates of Solvolysis of Benzoyl and P-Nitrobenzoyl P-Toluenesulfonates. JOURNAL OF CHEMICAL RESEARCH 2014. [DOI: 10.3184/174751914x14018022669011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Dennis N. Kevill
- Department of Chemistry and Biochemistry, Northern Illinois University DeKalb, Illinois 60115-2862, USA
| | - Zoon Ha Ryu
- Department of Chemistry, Dong-Eui University, 995 Eomgwango, Busan-Jin-Gu, Busan 614-714, Republic of Korea
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20
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Kevill DN, Ryu ZH. Correlation of the rates of solvolysis of acetic p
-toluenesulfonic anhydride (acetyl p
-toluenesulfonate) and a comparison with acetyl halides. J PHYS ORG CHEM 2013. [DOI: 10.1002/poc.3146] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Dennis N. Kevill
- Department of Chemistry and Biochemistry; Northern Illinois University; DeKalb IL 60115-2862 USA
| | - Zoon Ha Ryu
- Department of Chemistry; Dong-Eui University; 995 Eomgwango, Busan-Jin-Gu Busan 614-714 Korea
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21
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Park BC, Kevill DN. Extent of Nucleophilic Participation in the Solvolyses of an Aryl Chloromethyl Ether, α, p-Dichloroanisole. JOURNAL OF CHEMICAL RESEARCH 2013. [DOI: 10.3184/174751913x13734534378121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The specific rates of solvolysis of α, p-dichloroanisole (chloromethyl p-chlorophenyl ether, 1) have been measured conductimetrically in a variety of hydroxylic solvents. In three typical solvents, at 25.0 °C, the rate is 20–45 times greater than for the corresponding sulfide. In a comparison with the solvolysis of a substrate with an alkyl group replacing the aryl group, chloromethyl ethyl ether (2), at −10.0 °C in four typical solvents, 1 reacted considerably more slowly than 2, by a little over four orders of magnitude. An extended Grunwald–Winstein equation treatment of the specific rates of solvolyses in 24 solvents at 25.0 °C leads to an l value of 0.68 ± 0.04 and an m value of 0.59 ± 0.03 ( l/ m = 1.15). Appreciable nucleophilic assistance in the progress to the transition state is indicated and either nucleophilic solvation to an ionisation process or a loose SN2 transition state with extensive bond-breaking accompanied by a smaller degree of bond-making lead to an appropriate transition state.
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Affiliation(s)
- Byoung-Chun Park
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL 60115-2862, USA
| | - Dennis N. Kevill
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL 60115-2862, USA
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D’Souza MJ, Givens AF, Lorchak PA, Greenwood AE, Gottschall SL, Carter SE, Kevill DN. Kinetic studies that evaluate the solvolytic mechanisms of allyl and vinyl chloroformate esters. Int J Mol Sci 2013; 14:7286-301. [PMID: 23549265 PMCID: PMC3645686 DOI: 10.3390/ijms14047286] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Revised: 03/26/2013] [Accepted: 03/28/2013] [Indexed: 01/12/2023] Open
Abstract
At 25.0 °C the specific rates of solvolysis for allyl and vinyl chloroformates have been determined in a wide mix of pure and aqueous organic mixtures. In all the solvents studied, vinyl chloroformate was found to react significantly faster than allyl chloroformate. Multiple correlation analyses of these rates are completed using the extended (two-term) Grunwald-Winstein equation with incorporation of literature values for solvent nucleophilicity (NT) and solvent ionizing power (YCl). Both substrates were found to solvolyze by similar dual bimolecular carbonyl-addition and unimolecular ionization channels, each heavily dependent upon the solvents nucleophilicity and ionizing ability.
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Affiliation(s)
- Malcolm J. D’Souza
- Department of Chemistry, Wesley College, 120 N. State Street, Dover, DE 19901-3875, USA
- Authors to whom correspondence should be addressed; E-Mails: (M.J.D.); (D.N.K.); Tel.: +1-302-736-2528 (M.J.D.); +1-815-753-6882 (D.N.K.); Fax: +1-302-736-2301 (M.J.D.); +1-815-753-4802 (D.N.K.)
| | - Aaron F. Givens
- Department of Chemistry, Wesley College, 120 N. State Street, Dover, DE 19901-3875, USA
| | - Peter A. Lorchak
- Department of Chemistry, Wesley College, 120 N. State Street, Dover, DE 19901-3875, USA
| | - Abigail E. Greenwood
- Department of Chemistry, Wesley College, 120 N. State Street, Dover, DE 19901-3875, USA
| | - Stacey L. Gottschall
- Department of Chemistry, Wesley College, 120 N. State Street, Dover, DE 19901-3875, USA
| | - Shannon E. Carter
- Department of Chemistry, Wesley College, 120 N. State Street, Dover, DE 19901-3875, USA
| | - Dennis N. Kevill
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL 60115-2862, USA
- Authors to whom correspondence should be addressed; E-Mails: (M.J.D.); (D.N.K.); Tel.: +1-302-736-2528 (M.J.D.); +1-815-753-6882 (D.N.K.); Fax: +1-302-736-2301 (M.J.D.); +1-815-753-4802 (D.N.K.)
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Affiliation(s)
- Konstantin Troshin
- Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13 (Haus F), 81377 München, Germany
| | - Herbert Mayr
- Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13 (Haus F), 81377 München, Germany
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Evaluation of Electronic Effects in the Solvolyses of p-Methylphenyl and p-Chlorophenyl Chlorothionoformate Esters. J CHEM-NY 2013; 2013. [PMID: 24377055 DOI: 10.1155/2013/248534] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The solvolyses of p-tolyl chlorothionoformate and p-chlorophenyl chlorothionoformate are studied in a variety of organic mixtures of widely varying nucleophilicity and ionizing power values. This solvolytic data is accumulated at 25.0 °C using the titration method. An analysis of the rate data using the extended (two-term) Grunwald-Winstein equation, and the concept of similarity of substrates based on their l/m ratios, shows the occurrence of simultaneous side-by-side addition-elimination and unimolecular SN1 mechanisms.
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25
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Troshin K, Mayr H. Ion Pair Dynamics: Solvolyses of Chiral 1,3-Diarylallyl Carboxylates as a Case Study. J Am Chem Soc 2012. [DOI: 10.1021/ja308670g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Konstantin Troshin
- Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13 (Haus F), 81377
München, Germany
| | - Herbert Mayr
- Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13 (Haus F), 81377
München, Germany
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26
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Bentley TW. A comprehensive N
+
scale of nucleophilicity in an equation including a Swain-Scott response/selectivity parameter. J PHYS ORG CHEM 2012. [DOI: 10.1002/poc.3067] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- T. William Bentley
- Chemistry Unit, Grove Building, College of Medicine; Swansea University; Swansea SA2 8PP Wales UK
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Park BC, Kevill DN. Extent of Nucleophilic Participation in the Solvolyses of Alkyl Chloromethyl Ethers and Sulfides. JOURNAL OF CHEMICAL RESEARCH 2012. [DOI: 10.3184/174751912x13469242440149] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The specific rates of solvolysis have been determined for chloromethyl ethyl ether (3) and chloromethyl octyl ether (4) at −10.0 °C and for chloromethyl methyl sulfide (5) at 25.0 °C in a variety of pure and binary solvents. These values were used for a correlation analysis treatment using the extended Grunwald–Winstein equation incorporating literature values for solvent nucleophilicity ( NT) and solvent ionising power ( YCl). Appreciable values were found for the sensitivities towards changes in both NT and YCl values. Using a literature specific rate of hydrolysis at 25.0 °C for fluoromethyl methyl ether (2), the required value for chloromethyl methyl ether (1) was obtained from use of NT and YCl values and the sensitivities for 3 to changes in their values, to adjust an experimental specific rate value for 1 in 100% ethanol to the corresponding value in 100% water. In this way, an estimated kCl/ kF of 1.2 × 105 was obtained, essentially identical to values for the solvolyses of tert-butyl halides. A unimolecular mechanism for the solvolyses, with appreciable nucleophilic solvation of the developing carbocation, is proposed. Electronic supplementary information provides, for several solvents, specific rates of solvolysis for 3, 4, and 5 at additional temperatures and the calculated activation parameters.
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Affiliation(s)
- Byoung-Chun Park
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL 60115-2862, USA
| | - Dennis N. Kevill
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL 60115-2862, USA
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Park KH, Kevill DN. The importance of the ortho effect in the solvolyses of 2,6-difluorobenzoyl chloride. J PHYS ORG CHEM 2012. [DOI: 10.1002/poc.1906] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Kyoung-Ho Park
- Department of Chemistry and Biochemistry; Northern Illinois University; DeKalb; IL; 60115-2862; USA
| | - Dennis N. Kevill
- Department of Chemistry and Biochemistry; Northern Illinois University; DeKalb; IL; 60115-2862; USA
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Use of Linear Free Energy Relationships (LFERs) to elucidate the mechanisms of reaction of a γ-methyl-β-alkynyl and an ortho-substituted aryl chloroformate ester. Int J Mol Sci 2012; 13:665-682. [PMID: 22312278 PMCID: PMC3269712 DOI: 10.3390/ijms13010665] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 01/05/2012] [Accepted: 01/05/2012] [Indexed: 01/13/2023] Open
Abstract
The specific rates of solvolysis of 2-butyn-1-yl-chloroformate (1) and 2-methoxyphenyl chloroformate (2) are studied at 25.0 °C in a series of binary aqueousorganic mixtures. The rates of reaction obtained are then analyzed using the extended Grunwald-Winstein (G-W) equation and the results are compared to previously published G-W analyses for phenyl chloroformate (3), propargyl chloroformate (4), p-methoxyphenyl choroformate (5), and p-nitrophenyl chloroformate (6). For 1, the results indicate that dual side-by-side addition-elimination and ionization pathways are occurring in some highly ionizing solvents due to the presence of the electron-donating γ-methyl group. For 2, the analyses indicate that the dominant mechanism is a bimolecular one where the formation of a tetrahedral intermediate is rate-determining.
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Park KH, Kevill DN. Correlation of the Rates of Solvolysis of 3,4,5-trimethoxy- and 2,4,6-trichlorobenzoyl chlorides. JOURNAL OF CHEMICAL RESEARCH 2011. [DOI: 10.3184/174751911x13192929905095] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The introduction of methoxy groups into the 3- and 5-positions of 4-methoxybenzoyl chloride leads to a reduction in specific rates of solvolysis. An extended Grunwald–Winstein equation correlation for the specific rates of solvolysis of 3,4,5-trimethoxybenzoyl chloride gives sensitivities towards changes in solvent nucleophilicity (/ value) of 0.29 and towards changes in solvent ionising power ( m value) of 0.54. The low m value allows specific rates to be determined in highly ionising fluoroalcohol-H2O mixtures. A parallel correlation of the specific rates of solvolysis of 2,4,6-trichlorobenzoyl chloride reveals that solvolyses in 100% and 90% ethanol or methanol do not appreciably follow the ionisation pathway indicated for solvolyses in the other solvents and it is proposed that, despite the two ortho-substituents, the addition–elimination pathway has become dominant.
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Affiliation(s)
- Kyoung-Ho Park
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL 60115-2862, USA
| | - Dennis N. Kevill
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL 60115-2862, USA
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D'Souza MJ, Darrington AM, Kevill DN. A Study of Solvent Effects in the Solvolysis of Propargyl Chloroformate. ISRN ORGANIC CHEMISTRY 2011; 2011. [PMID: 21666878 PMCID: PMC3111911 DOI: 10.5402/2011/767141] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The specific rates of solvolysis of propargyl chloroformate (1) are analyzed in 22 solvents of widely varying nucleophilicity and ionizing power values at 25.0 °C using the extended Grunwald-Winstein equation. Sensitivities to solvent nucleophilicity (l) of 1.37 and to solvent ionizing power (m) of 0.47 suggest a bimolecular process with the formation of a tetrahedral intermediate. A plot of the rates of solvolysis of 1 against those previously reported for phenyl chloroformate (2) results in a correlation coefficient (R) of 0.996, a slope of 0.86, and an F-test value of 2161. The unequivocal correlation between these two substrates attest that the stepwise association-dissociation (A(N) + D(N)) mechanism previously proposed for 2 is also operative in 1.
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Affiliation(s)
- Malcolm J D'Souza
- Department of Chemistry, Wesley College, 120 N. State Street, Dover, Delaware 19901-3875, USA
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32
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Kevill DN, Park KH, Koh HJ. Further consideration of the correlation of the rates of solvolytic displacement of chloride ion from phosphorus (V). J PHYS ORG CHEM 2011. [DOI: 10.1002/poc.1767] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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33
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D’Souza MJ, McAneny MJ, Kevill DN, Kyong JB, Choi SH. Kinetic evaluation of the solvolysis of isobutyl chloro- and chlorothioformate esters. Beilstein J Org Chem 2011; 7:543-52. [PMID: 21647255 PMCID: PMC3107482 DOI: 10.3762/bjoc.7.62] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Accepted: 04/13/2011] [Indexed: 11/23/2022] Open
Abstract
The specific rates of solvolysis of isobutyl chloroformate (1) are reported at 40.0 °C and those for isobutyl chlorothioformate (2) are reported at 25.0 °C, in a variety of pure and binary aqueous organic mixtures with wide ranging nucleophilicity and ionizing power. For 1, we also report the first-order rate constants determined at different temperatures in pure ethanol (EtOH), methanol (MeOH), 80% EtOH, and in both 97% and 70% 2,2,2-trifluoroethanol (TFE). The enthalpy (ΔH(≠)) and entropy (ΔS(≠)) of activation values obtained from Arrhenius plots for 1 in these five solvents are reported. The specific rates of solvolysis were analyzed using the extended Grunwald-Winstein equation. Results obtained from correlation analysis using this linear free energy relationship (LFER) reinforce our previous suggestion that side-by-side addition-elimination and ionization mechanisms operate, and the relative importance is dependent on the type of chloro- or chlorothioformate substrate and the solvent.
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Affiliation(s)
- Malcolm J D’Souza
- Department of Chemistry, Wesley College, 120 N. State Street, Dover, DE 19901-3875, USA
| | - Matthew J McAneny
- Department of Chemistry, Wesley College, 120 N. State Street, Dover, DE 19901-3875, USA
| | - Dennis N Kevill
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL 60115-2862, USA
| | - Jin Burm Kyong
- Department of Chemistry & Applied Chemistry, Hanyang University, Ansan-si, Gyeonggi-do, 426-791, Korea
| | - Song Hee Choi
- Department of Chemistry & Applied Chemistry, Hanyang University, Ansan-si, Gyeonggi-do, 426-791, Korea
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34
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Park KH, Kevill DN. Influence of the ortho
effect in the solvolyses of dichlorobenzoyl chlorides. J PHYS ORG CHEM 2011. [DOI: 10.1002/poc.1851] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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35
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Bentley TW. Nucleophilicity parameters for strong nucleophiles in dimethyl sulfoxide. A direct alternative to the s(E + N) equation. J PHYS ORG CHEM 2011. [DOI: 10.1002/poc.1747] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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36
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Bentley TW. Limitations of the s(E+N) and Related Equations: Solvent Dependence of Electrophilicity. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201005816] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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37
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Bentley TW. Limitations of the s(E+N) and Related Equations: Solvent Dependence of Electrophilicity. Angew Chem Int Ed Engl 2011; 50:3608-11; author reply 3612-8. [DOI: 10.1002/anie.201005816] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Indexed: 11/12/2022]
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Correlation of the rates of solvolysis of neopentyl chloroformate-a recommended protecting agent. Int J Mol Sci 2011; 12:1161-74. [PMID: 21541050 PMCID: PMC3083697 DOI: 10.3390/ijms12021161] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Revised: 01/30/2011] [Accepted: 02/09/2011] [Indexed: 11/17/2022] Open
Abstract
The specific rates of solvolysis of neopentyl chloroformate (1) have been determined in 21 pure and binary solvents at 45.0 °C. In most solvents the values are essentially identical to those for ethyl and n-propyl chloroformates. However, in aqueous-1,1,1,3,3,3-hexafluoro-2-propanol mixtures (HFIP) rich in fluoroalcohol, 1 solvolyses appreciably faster than the other two substrates. Linear free energy relationship (LFER) comparison of the specific rates of solvolysis of 1 with those for phenyl chloroformate and those for n-propyl chloroformate are helpful in the mechanistic considerations, as is also the treatment in terms of the Extended Grunwald-Winstein equation. It is proposed that the faster reaction for 1 in HFIP rich solvents is due to the influence of a 1,2-methyl shift, leading to a tertiary alkyl cation, outweighing the only weak nucleophilic solvation of the cation possible in these low nucleophilicity solvents.
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Bentley TW. Nucleophilicity parameters for amines, amino acids and peptides in water. Variations in selectivities for quinone methides. Org Biomol Chem 2011; 9:6685-90. [DOI: 10.1039/c1ob05715d] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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40
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Koh HJ, Kang SJ, Kevill DN. Rate and Product Studies in the Solvolyses of Two Cyclic Phosphorochloridate Esters. PHOSPHORUS SULFUR 2010. [DOI: 10.1080/10426500903061525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Han Joong Koh
- a Department of Science Education , Chonju National University of Education , Chonju, Korea
| | - Suk Jin Kang
- a Department of Science Education , Chonju National University of Education , Chonju, Korea
| | - Dennis N. Kevill
- b Department of Chemistry and Biochemistry , Northern Illinois University , DeKalb, Illinois, USA
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On the Importance of the Aromatic Ring Parameter in Studies of the Solvolyses of Cinnamyl and Cinnamoyl Halides. ACTA ACUST UNITED AC 2010; 2010:1-9. [PMID: 21552456 DOI: 10.1155/2010/130506] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In solvolysis studies using Grunwald-Winstein plots, dispersions were observed for substrates with aromatic rings at the α-carbon. Several examples for the unimolecular solvolysis of monoaryl benzylic derivatives and related diaryl- or naphthyl- substituted derivatives have now been reported, where the application of the aromatic ring parameter (I) removes this dispersion. A recent claim suggesting the presence of an appreciable nucleophilic component to the I scale, has now been shown, in a review of the solvolysis of highly-hindered alkyl halides, to be unlikely to be correct. Attention is now focused on the application of the hI term for the solvolysis of compounds containing a double bond in the vicinity of any developing carbocation. Available specific rates of solvolysis (plus some new values) at 25°C of cinnamyl chloride, cinnamyl bromide, cinnamoyl chloride, p-chlorocinnamoyl chloride, and p-nitrocinnamoyl chloride are analyzed using the simple and extended (including the hI term) Grunwald-Winstein equations.
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D’Souza MJ, Mahon BP, Kevill DN. Analysis of the nucleophilic solvation effects in isopropyl chlorothioformate solvolysis. Int J Mol Sci 2010; 11:2597-611. [PMID: 20717524 PMCID: PMC2920554 DOI: 10.3390/ijms11072597] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Revised: 06/21/2010] [Accepted: 06/28/2010] [Indexed: 12/04/2022] Open
Abstract
Correlation of the solvent effects through application of the extended Grunwald-Winstein equation to the solvolysis of isopropyl chlorothioformate results in a sensitivity value of 0.38 towards changes in solvent nucleophilicity (l) and a sensitivity value of 0.72 towards changes in solvent ionizing power (m). This tangible l value coupled with the negative entropies of activation observed indicates a favorable predisposition towards a modest rear-side nucleophilic solvation of a developing carbocation. Only in 100% ethanol was the bimolecular pathway dominant. These observations are very different from those obtained for the solvolysis of isopropyl chloroformate, where dual reaction channels were proposed, with the addition-elimination reaction favored in the more nucleophilic solvents and a unimolecular fragmentation-ionization mechanism favored in the highly ionizing solvents.
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Affiliation(s)
- Malcolm J. D’Souza
- Department of Chemistry, Wesley College, 120 N. State Street, Dover, DE 19901-3875, USA
| | - Brian P. Mahon
- Department of Chemistry, Wesley College, 120 N. State Street, Dover, DE 19901-3875, USA
| | - Dennis N. Kevill
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL 60115-2862, USA
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D’Souza MJ, Hailey SM, Kevill DN. Use of empirical correlations to determine solvent effects in the solvolysis of S-methyl chlorothioformate. Int J Mol Sci 2010; 11:2253-66. [PMID: 20559514 PMCID: PMC2885106 DOI: 10.3390/ijms11052253] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Revised: 05/12/2010] [Accepted: 05/24/2010] [Indexed: 12/03/2022] Open
Abstract
The specific rates of solvolysis of S-methyl chlorothioformate (MeSCOCl) are analyzed in 20 solvents of widely varying nucleophilicity and ionizing power at 25.0 degrees C using the extended Grunwald-Winstein Equation. A stepwise S(N)1 (D(N) + A(N)) mechanism is proposed in the more ionizing solvents including six aqueous fluoroalcohols. In these solvents, a large sensitivity value of 0.79 towards changes in solvent nucleophilicity (l) is indicative of profound rearside nucleophilic solvation of the developing carbocation. In twelve of the more nucleophilic pure alchohols and aqueous solutions, the sensitivities obtained for solvent nucleophilicity (l) and solvent ionizing power (m) are similar to those found in acyl chlorides where an association-dissociation (A(N) + D(N)) mechanism is believed to be operative.
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Affiliation(s)
- Malcolm J. D’Souza
- Department of Chemistry, Wesley College, 120 N. State Street, Dover, Delaware 19901-3875, USA
| | - Stefan M. Hailey
- Department of Chemistry, Wesley College, 120 N. State Street, Dover, Delaware 19901-3875, USA
| | - Dennis N. Kevill
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois 60115-2862, USA
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Spillane WJ, Malaubier JB. Mechanism of the hydrolysis of the sulfamate EMATE—an irreversible steroid sulfatase inhibitor. Tetrahedron Lett 2010. [DOI: 10.1016/j.tetlet.2010.02.065] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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45
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Koh HJ, Kevill DN. Correlation of the Rates of Solvolysis of Chlorodiphenylphosphine Using the Extended Grunwald–Winstein Equation. PHOSPHORUS SULFUR 2010. [DOI: 10.1080/10426500903012478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Han Joong Koh
- a Department of Science Education , Chonju National University of Education , Chonju, Korea
| | - Dennis N. Kevill
- b Department of Chemistry and Biochemistry , Northern Illinois University , DeKalb, Illinois, USA
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Santhosh Kumar D, Jayakumar KP, Balachandran S. The leaving group dependence in the rates of solvolysis of 1,2-diphenylethyl system. J PHYS ORG CHEM 2010. [DOI: 10.1002/poc.1662] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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48
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Bentley TW, Jones RO, Kang DH, Koo IS. The SN3-SN2 spectrum. Rate constants and product selectivities for solvolyses of benzenesulfonyl chlorides in aqueous alcohols. J PHYS ORG CHEM 2009. [DOI: 10.1002/poc.1522] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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