Effect of methanol on the regioselectivity and reaction rate of 1,3-dipolar cycloaddition of methyldiazoacetate to methyl acrylate and butene-1

Хурсан, С. Л.; Samarkina, A. B.

doi:10.1016/j.theochem.2010.08.003

Cited by 6 publications

(9 citation statements)

References 34 publications

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“…The computational implementation of the Hard and Soft Acids and Bases principle (HSAB) has been successfully adopted to rationalize a wide variety of chemical reactions . These include the nucleophilic addition to epoxides and aziridines, although only with limited types of nucleophiles .…”

Section: Introductionmentioning

confidence: 99%

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Regioselectivity and stereoselectivity of nucleophilic addition to glycal and imino‐glycal vinyl epoxides and their carba analogs: a rationalization based on HSAB theory and MEP

Favero

Crotti

Bussolo

et al. 2015

J of Physical Organic Chem

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Besides the usual parameters for softness (Fukui indexes) and hardness (atomic charges), novel parameters, obtained from the molecular electrostatic potential on the van der Waals surface (ESP-indexes), were considered as stereochemical and possible hardness descriptors. The effect of oxirane ring activation by electrophiles was modeled by scanning the aforementioned parameters over the epoxide ring opening in the neutral substrates and in two corresponding protonated derivatives. C(1) is a softer center than C(3), but oxirane activation rapidly levels softness and shifts hardness from C(3) to C(1); with carbocycles, C(1) and C(3) hardness are leveled, and with heterocycles, C(1) becomes harder than C(3). ESP-indexes are suitable parameters to account for stereoselectivity and more reliable hardness descriptors than the atomic charges. An explanation for the prevailing syn-C(1)-selectivity observed with glycals and iminoglycals epoxides versus the anti-C(3)-selectivity observed with carba analogs is given. A rationalization of Ferrier rearrangement is also provided.

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Section: Introductionmentioning

confidence: 99%

“…For the sake of completeness, we also considered the effect of medium polarity, whose ability to affect the regiochemistry by modifying local softness and hardness is well known …”

Section: Introductionmentioning

confidence: 99%

Regioselectivity and stereoselectivity of nucleophilic addition to glycal and imino‐glycal vinyl epoxides and their carba analogs: a rationalization based on HSAB theory and MEP

Favero

Crotti

Bussolo

et al. 2015

J of Physical Organic Chem

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“…The activation enthalpy of the [3+2]-cycloaddition of MDA to MA was found to be 59.5 kJ·mol –1 in excellent agreement with kinetic measurements. Earlier an activation energy of 68.7 kJ·mol –1 was calculated using moderate level of theory B3LYP/6-31G(d) . Thus, the kinetic arguments also evidence in favor of the noncatalytic MDA/MA interaction via concerted cycloaddition of reagents into 3 H -pyrazoline.…”

Section: Results and Discussionmentioning

confidence: 89%

Section: ■ Results and Discussionmentioning

confidence: 99%

“…According to the FMO theory 23,24 reaction of methyl diazoacetate (dipole, 1) with methyl acrylate (dipolarophil, 2) is controlled by the HOMO (1) /LUMO (2) orbital interaction. 24 Indeed, we have estimated the value Δε = ε LUMO (2) − ε HOMO (1) to be 0.1407 au which is 0.0479 au lesser than the HOMO (2) / LUMO (1) gap (Figure 1). In the framework of the FMO formalism a catalytic effect of LB should manifest itself in the lowering of Δε as a result of • increasing the HOMO (1) energy, i.e., enhancing of diazo ester nucleophilicity; • decreasing the ε LUMO (2) , i.e., growth of electron deficit on the CC bond in MA;…”

Section: ■ Results and Discussionmentioning

confidence: 99%

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Nature of Lewis Base Catalysis of 1,3-Dipolar Cycloaddition of Methyl Diazoacetate to Methyl Acrylate; NMR Kinetic Spectroscopy and DFT Study

et al. 2017

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The effect of Lewis base (LB) in the domino reaction between methyl diazoacetate and methyl acrylate has been studied. This domino process is initialized by a [3+2]-cycloaddition reaction to generate 3H-pyrazoline followed by a subsequent 1,3-H shift reaction forming 1H-pyrazoline as the more stable isomer. The rate of the first step is not sensitive to the presence of LBs (THF, Py, DMAP, DBU, and triphenylphosphine) as it was evidenced by kinetic nuclear magnetic resonance spectroscopy and quantum chemical modeling. LBs manifest remarkable catalytic effect on the second step of the reaction only acting as proton acceptor. DFT calculations reveal fine correlation between enthalpy of proton transfer from trans-3H-pyrazoline to LB and basic strength of the latter described in terms of BF-affinity scale. Under conditions of LB catalysis the reaction rate of the first step (methyl diazoacetate and methyl acrylate interaction) limits the rate of 3H → 1H pyrazoline isomerization and, therefore, restricts catalytic efficiency of LB. An alternative mechanism for catalysis of the 1,3-dipolar cycloaddition through formation of triazene-like intermediate during reaction of diazo acetate with LB and following Michael addition of intermediate to alkene was carefully analyzed. This reaction scheme was not confirmed in our experiments.

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DFT study of 1,3-dipolar cycloaddition of azomethine imines with electron deficient dipolarophiles acrylonitrile, methylpropenoate, and dimethylmaleate

Das¹,

Salampuria

Banerjee

2012

Computational and Theoretical Chemistry

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Effect of methanol on the regioselectivity and reaction rate of 1,3-dipolar cycloaddition of methyldiazoacetate to methyl acrylate and butene-1

Cited by 6 publications

References 34 publications

Regioselectivity and stereoselectivity of nucleophilic addition to glycal and imino‐glycal vinyl epoxides and their carba analogs: a rationalization based on HSAB theory and MEP

Regioselectivity and stereoselectivity of nucleophilic addition to glycal and imino‐glycal vinyl epoxides and their carba analogs: a rationalization based on HSAB theory and MEP

Nature of Lewis Base Catalysis of 1,3-Dipolar Cycloaddition of Methyl Diazoacetate to Methyl Acrylate; NMR Kinetic Spectroscopy and DFT Study

DFT study of 1,3-dipolar cycloaddition of azomethine imines with electron deficient dipolarophiles acrylonitrile, methylpropenoate, and dimethylmaleate

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