Kinetics and mechanism of the aminolysis of bis(4‐nitrophenyl) carbonate and <i>O</i>‐(4‐nitropheny) S‐(4‐nitrophenyl) thio and dithiocarbonate

Castro, Enrique A.; Aliaga, Margarita E.; Gazitúa, Marcela; Pavez, Paulina; Santos, José G.

doi:10.1002/poc.3231

Cited by 17 publications

(27 citation statements)

References 21 publications

(59 reference statements)

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“…The β nuc value found for the reaction of 2a is smaller than that reported for the corresponding reaction of 1a ( i.e ., β nuc = 0.89). However, a β nuc value of 0.6 ± 0.1 has often been reported for reactions proceeding through a concerted mechanism . Thus, one can suggest that the reaction of 2a with quinuclidines also proceeds through a concerted mechanism.…”

Section: Resultsmentioning

confidence: 99%

“…Many factors are known to affect reactivity of esters ( e.g ., nucleofugality of the leaving group, steric hindrance, inductive effect, resonance stabilization, and so on) . As compounds 1a and 2a possess the same leaving group ( i.e ., 3,4‐dinitrophenoxide) and reaction center ( i.e ., a CS bond), the reactivity difference between 1a and 2a is not due to any difference in the nucleofugality of the leaving group.…”

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…Numerous studies on nucleophilic substitution (S N ) reactions of esters with amines have been carried out to investigate the reaction mechanism . However, amines used as a nucleophile are mostly primary and secondary amines . In general, S N reactions of esters with primary or secondary amines have been reported to proceed through a concerted mechanism or via a stepwise pathway with one or two intermediates ( e.g ., a zwitterionic tetrahedral intermediate T ± and its deprotonated form T − ) .…”

Section: Introductionmentioning

confidence: 99%

“…However, amines used as a nucleophile are mostly primary and secondary amines . In general, S N reactions of esters with primary or secondary amines have been reported to proceed through a concerted mechanism or via a stepwise pathway with one or two intermediates ( e.g ., a zwitterionic tetrahedral intermediate T ± and its deprotonated form T − ) . Factors suggested to affect the reaction mechanism are nature of the electrophilic center ( e.g ., CO vs. CS) and the reaction medium ( e.g ., protic vs. aprotic), basicity of the leaving group and incoming amine, and so on …”

Section: Introductionmentioning

confidence: 99%

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Kinetic Study on Quinuclidinolysis of O‐Phenyl O‐Y‐substituted‐Phenyl Thionocarbonates: Effects of Changing Nonleaving Group from Thionobenzoyl to Phenyloxythionocarbonyl on Reactivity and Transition‐State Structure

Koh

2017

Bulletin Korean Chem Soc

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Second-order rate constants (k quin ) for reactions of O-3,4-dinitrophenyl O-phenyl thionocarbonate (2a) with a series of quinuclidine derivatives and for those of O-phenyl O-Y-substituted-phenyl thionocarbonates (2a-2h) with quinuclidine in 80 mol % H 2 O/20 mol % DMSO at 25.0 AE 0.1 C are reported. Comparison of the k quin values in this study with those reported previously for the corresponding reactions of O-3,4-dinitrophenyl thionobenzoate (1a) and O-Y-substituted-phenyl thionobenzoates (1a-1j) has revealed that 2a is more reactive than 1a toward all the quinuclidine derivatives studied, while the thionocarbonate esters possessing a weak electron-withdrawing group in the leaving group (e.g., 2g and 2h) are less reactive than the corresponding thionobenzoate esters (e.g., 1g and 1h) toward quinuclidine. The Brønsted-type plots for the reactions of 2a with quinuclidine derivatives and for those of 2a-2h with quinuclidine are linear with β nuc = 0.67 and β lg = −0.85, respectively, indicating that the reactions proceed through a concerted mechanism with a loose transition state (TS). This is in contrast to the report that the corresponding reactions of 1a-1j proceed through a forced concerted mechanism with a tight TS on the basis of the linear Brønsted-type plots with β nuc = 0.89 and β lg = −0.37. Factors that control the reactivity of these esters toward quinuclidine are discussed in detail.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Kinetic Study on Quinuclidinolysis of O‐Phenyl O‐Y‐substituted‐Phenyl Thionocarbonates: Effects of Changing Nonleaving Group from Thionobenzoyl to Phenyloxythionocarbonyl on Reactivity and Transition‐State Structure

Koh

2017

Bulletin Korean Chem Soc

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Reactions of Carboxylic, Phosphoric, and Sulfonic Acids and their Derivatives

Bedford

2017

Organic Reaction Mechanisms · 2014

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Kinetic Study on Reactions of O‐Y‐substituted Phenyl Thionobenzoates with Quinuclidine: Factors Governing Reactivity and Reaction Mechanism

Yang

Kim

2015

Bulletin Korean Chem Soc

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Second‐order rate constants (k quin) for the reactions of O‐Y‐substituted phenyl thionobenzoates (3a–3i) with quinuclidine have been measured spectrophotometrically. Comparison of k quin with the rate constants reported previously for the corresponding reactions with benzylamine (k BzNH2) has revealed that quinuclidine is less reactive than benzylamine toward 3a–3i although the former is 2.1 pK a units more basic than the latter. Steric hindrance exerted by quinuclidine has been suggested to be responsible for the decreased reactivity of the tertiary amine. The Brønsted‐type plot for the reactions of 3a–3i with quinuclidine is linear with βlg = −0.37. The Hammett plot correlated with σ Y o constants exhibits many scattered points ( R 2 = 0.982). In contrast, the Yukawa‐Tsuno plot results in an excellent linear correlation ( R 2 = 0.9992) with ρ Y = 0.96 and r = 0.51, indicating that a negative charge develops partially on the O atom of the leaving group. Thus, the reactions of 3a–3i with quinuclidine have been concluded to proceed through a concerted mechanism in which expulsion of the leaving group is advanced only a little in the rate‐determining transition state.

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Kinetics and mechanism of the aminolysis of bis(4‐nitrophenyl) carbonate and O‐(4‐nitropheny) S‐(4‐nitrophenyl) thio and dithiocarbonate

Cited by 17 publications

References 21 publications

Kinetic Study on Quinuclidinolysis of O‐Phenyl O‐Y‐substituted‐Phenyl Thionocarbonates: Effects of Changing Nonleaving Group from Thionobenzoyl to Phenyloxythionocarbonyl on Reactivity and Transition‐State Structure

Kinetic Study on Quinuclidinolysis of O‐Phenyl O‐Y‐substituted‐Phenyl Thionocarbonates: Effects of Changing Nonleaving Group from Thionobenzoyl to Phenyloxythionocarbonyl on Reactivity and Transition‐State Structure

Reactions of Carboxylic, Phosphoric, and Sulfonic Acids and their Derivatives

Kinetic Study on Reactions of O‐Y‐substituted Phenyl Thionobenzoates with Quinuclidine: Factors Governing Reactivity and Reaction Mechanism

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