Stereospecificity in the Rearrangement of Amino Alcohols

Pollak, Peter; Curtin, David V.

doi:10.1021/ja01158a082

Cited by 35 publications

(16 citation statements)

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“…The deamination of labeled 2-amino-l,l,2-triphenylethanol also has been studied. The results of the present research are explained in terms of open carbonium ion intermediates whose rotation about the C-C+ bond is restricted and whose phenyl arrangement; and (3) that the steric factor, called the "cú-efíect" by Curtin,2 "is a function only of the difference in free energy between the two transition states for the rearrangement step and is independent of the relative populations of the conformations of the initial molecule. "3 An alternate possibility involves the formation, from II, of ion III.…”

Section: Discussionmentioning

confidence: 85%

Basicity Constants and Rates of Hydration of Some Imines¹

Buist¹,

Lucas²

1957

J. Am. Chem. Soc.

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The Kb values of a number of imines and their N-ethyl derivatives lie in the range 0.8 to 4.7 X 10 ~6 with the exception of Z ra res-N-ethy 1-2,3-iminobutane for which the value of 27 X 10_e is inexplicably high. The perchloric acid-catalyzed rates of hydration of imines increase in the order: 1,2-iminoethane, 1,2-iminopropane and l,2-imino-2-methylpropane. The order is consistent with predominantly Sn2 mechanism at a primary carbon atom, mixed SnI and Sn2 mechanisms at a secondary carbon atom and predominantly SnI mechanism at a tertiary carbon atom.(1) This research has been made possible by support extended to the California Institute of Technology by the Office of Ordnance Research under Contract No. DA-04-495-Ord-410.(2) To whom requests for reprints should be sent.

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Section: Discussionmentioning

confidence: 85%

Basicity Constants and Rates of Hydration of Some Imines¹

Buist¹,

Lucas²

1957

J. Am. Chem. Soc.

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“…15 The investigations above lead to the conclusion that H abstraction from the O−H bond of HOCl by HO • is more reasonable, as this mechanism is consistent with the observed product (i.e., ClO • ). Furthermore, our estimation of k exp for HO • is supported by the Curtin−Hammett principle 54,55 describing that dominant species (i.e., HOCl) in equilibrium with OCl − at pH below pK a has lower reactivity with an identical reactant (i.e., HO • ) compared to that for minor species (OCl − ).…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Mechanistic Insight into the Reactivity of Chlorine-Derived Radicals in the Aqueous-Phase UV–Chlorine Advanced Oxidation Process: Quantum Mechanical Calculations

Minakata

Kamath

Maetzold

2017

Environ. Sci. Technol.

116

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The combined ultraviolet (UV) and free chlorine (UV-chlorine) advanced oxidation process that produces highly reactive hydroxyl radicals (HO) and chlorine radicals (Cl) is an attractive alternative to UV alone or chlorination for disinfection because of the destruction of a wide variety of organic compounds. However, concerns about the potential formation of chlorinated transformation products require an understanding of the radical-induced elementary reaction mechanisms and their reaction-rate constants. While many studies have revealed the reactivity of oxygenated radicals, the reaction mechanisms of chlorine-derived radicals have not been elucidated due to the data scarcity and discrepancies among experimental observations. We found a linear free-energy relationship quantum mechanically calculated free energies of reaction and the literature-reported experimentally measured reaction rate constants, k, for 22 chlorine-derived inorganic radical reactions in the UV-chlorine process. This relationship highlights the discrepancy among literature-reported rate constants and aids in the determination of the rate constant using quantum mechanical calculations. We also found linear correlations between the theoretically calculated free energies of activation and k for 31 reactions of Cl with organic compounds. The correlation suggests that H-abstraction and Cl-adduct formation are the major reaction mechanisms. This is the first comprehensive study on chlorine-derived radical reactions, and it provides mechanistic insight into the reaction mechanisms for the development of an elementary reaction-based kinetic model.

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“…The first factor determines the relative population of prereaction complexes from which the reactions proceed, and the second (kinetic) factor is related to the relative reaction rates from the prereaction complexes to the transition states (and subsequently to products). It would be extremely useful to discuss the present results by invoking the Curtin–Hammet principle: the relative amounts of products formed depend only on the difference in free energy of the transition states, provided the rates of reaction are slower than the rates of interconversion between the reactants. Since the time scale of the reactions studied here is typically a few hours, the equilibration of the CIP/SSIP prereactions complexes may be safely presumed.…”

Section: Resultsmentioning

confidence: 99%

Computational study of S_N2 reactions promoted by crown ether: Contact ion pair versus solvent‐separated ion pair mechanism

Lee

Jadhav

Kim

et al. 2017

Int J of Quantum Chemistry

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We examined by quantum chemical methods the mechanism of SN2 reaction using metal bromide MBr (M = Na, K, Cs) and KX (X= F, Cl) in CH3CN promoted by crown ether (18‐crown‐6). We focus on whether the metal salts react as a contact ion pair (CIP; M+ and X– in close contact) or as a solvent‐separated ion pair (SSIP; M+ and X– at large distance). In SSIP mechanism, X– is removed far enough from M+ for the metal salt to be considered as “separated” by the effects of the crown ether and the solvent. In the CIP picture, conversely, the coordination of 18‐crown‐6 to M+ is not sufficient to overcome the powerful Coulombic interactions between M+ and X–. We find that the CIP route is favored for SN2 bromination processes using MBr (M = Na, K, Cs). For SN2 reaction using KF, the feasibility of the two pathways is essentially equal, whereas for SN2 chlorination by KCl the SSIP route is predicted to be favored.

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Stereospecificity in the Rearrangement of Amino Alcohols

Cited by 35 publications

References 0 publications

Basicity Constants and Rates of Hydration of Some Imines¹

Basicity Constants and Rates of Hydration of Some Imines¹

Mechanistic Insight into the Reactivity of Chlorine-Derived Radicals in the Aqueous-Phase UV–Chlorine Advanced Oxidation Process: Quantum Mechanical Calculations

Computational study of S_N2 reactions promoted by crown ether: Contact ion pair versus solvent‐separated ion pair mechanism

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Stereospecificity in the Rearrangement of Amino Alcohols

Cited by 35 publications

References 0 publications

Basicity Constants and Rates of Hydration of Some Imines1

Basicity Constants and Rates of Hydration of Some Imines1

Mechanistic Insight into the Reactivity of Chlorine-Derived Radicals in the Aqueous-Phase UV–Chlorine Advanced Oxidation Process: Quantum Mechanical Calculations

Computational study of SN2 reactions promoted by crown ether: Contact ion pair versus solvent‐separated ion pair mechanism

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Product

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Basicity Constants and Rates of Hydration of Some Imines¹

Basicity Constants and Rates of Hydration of Some Imines¹

Computational study of S_N2 reactions promoted by crown ether: Contact ion pair versus solvent‐separated ion pair mechanism