A DFT study on nucleophilicity and site selectivity of nitrogen nucleophiles

Deuri, Sanjib; Phukan, Prodeep

doi:10.1016/j.comptc.2011.11.017

Cited by 22 publications

(17 citation statements)

References 34 publications

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“…Thus, β-lactams have a stronger C=O double bond and a more basic nitrogen than regular amides. 12 We envisioned that the nitrogen atom of the β-lactam should exhibit greater nucleophilicity toward arynes than normal amides, thus leading to eventual C(O)-N bond cleavage to afford dihydroquinolinones (Scheme 1). While this outcome proved correct, we have observed some interesting subsequent chemistry, which we now report.…”

Section: Introductionmentioning

confidence: 99%

Formation of Acridones by Ethylene Extrusion in the Reaction of Arynes with β-Lactams and Dihydroquinolinones

et al. 2012

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N-Unsubstituted β-lactams react with a molecule of aryne by insertion into the amide bond to form a 2,3-dihydroquinolin-4-one, which subsequently reacts with another molecule of aryne to form an acridone by extrusion of a molecule of ethylene. 2,3-Dihydroquinolin-4-ones react under the same reaction conditions to afford identical results. This is the first example of ethylene extrusion in aryne chemistry.

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Section: Introductionmentioning

confidence: 99%

Formation of Acridones by Ethylene Extrusion in the Reaction of Arynes with β-Lactams and Dihydroquinolinones

et al. 2012

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“…The applicability of philicity concept to various aspects of chemistry has been thoroughly scrutinized by Roy et al [33]. Recently we assessed the nucleophilic character of some silyl enol ethers and ketene silyl acetals using this index [34].…”

Section: Theoretical Backgroundmentioning

confidence: 99%

Catalytic effect of molecular iodine in Diels–Alder reaction: a density functional theory study

Deuri

Phukan

2011

Struct Chem

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We explore here the feasibility of employing molecular iodine as Lewis acid catalyst for Diels-Alder (DA) reaction using conceptual density functional theory (DFT) based reactivity indices and transition state analysis at the DFT (B3LYP)/6-31G(d) level of theory. Catalytic effect of iodine is probed using reactivity indices considering six different substituents for the diene at the 2-position and five different substituents at the 1-position of the olefinic dienophile. Comparison of HOMO diene-LUMO dienophile gap between the catalyzed and uncatalyzed processes confirms catalytic effect of iodine in DA reaction. Mechanistic details of both the uncatalyzed and the iodine catalyzed processes is achieved through transition state analysis for four possible stereoisomeric reactive channels with respect to isoprene-acrolein model reaction. A significant cutback in activation barrier is observed in presence of iodine. Influence of iodine on regioselectivity of the reaction and asynchronicity of bond formation is analyzed using local version of the HSAB principle and philicity index.

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“…3), similar to the dependence of PA N′ on the charge distribution (Àq N′ and Δq C¼N′ ), takes place only within the series of amidines 1-5 and ref lects the effect of the substituent at the amine nitrogen atom with the constant substituent CF 3 SO 2 at the imine nitrogen atom. Its replacement by MeSO 2 (6) or by methyl group (7) is accompanied by a decrease of E (2) and increase of PA N′ .…”

Section: Proton Aff Inities Of Trif Luoromethylsulfonylformamidines Amentioning

confidence: 99%

“…Protonation, as a rule, occurs at the imine nitrogen atom, so the pK a values of amidines are most sensitive to variation of the substituent at this atom, especially when a strong electron–donor or acceptor substituent is present. DFT calculations of the nucleophilicity index for 32 nitrogen‐containing compounds allowed to rank amidines among these compounds . Besides, it was shown that both nitrogen atoms can act as protonation sites.…”

Section: Introductionmentioning

confidence: 99%

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Basicity of trifluoromethylsulfonylformamidines. DFT and FTIR study and NBO analysis

Shainyan

Chípanina

Oznobikhina

et al. 2015

J. Phys. Org. Chem.

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The effect of the electron–acceptor substituent CF3SO2 at the imine nitrogen atom on the basicity and the electron distribution in N,N‐alkylformamidines (1, 2, 3, 4, 5) was studied experimentally by the FTIR spectroscopy and theoretically at the DFT (B3LYP/6‐311+G(d,p)) level of theory, including the natural bond orbital (NBO) analysis. The calculated proton affinities of the imine nitrogen atom and the sulfonyl oxygen (PAN′ and PAO) depend on the atomic charges, the CN′ and N′―S bond polarity and on the energy of interaction of the amine nitrogen and the oxygen lone pairs with antibonding π* and σ*‐orbitals. The basicity of the imine nitrogen atom is increased with the increase of the electron‐donating power of the substituent at the amine nitrogen atom due to stronger interaction nN → π*CN′, but is decreased for the electron‐withdrawing groups MeSO2 and CF3SO2 at the imine nitrogen atom in spite of the increase of this conjugation. Protonation of (1, 2, 3, 4, 5) in CH2Cl2 solution in the presence of CF3SO3H occurs at the imine nitrogen atom, while the formation of hydrogen bonds with 4‐fluorophenol takes place at the sulfonyl oxygen atom, whose basicity is lower than that of N,N′‐dimethylmethanesulfonamide but higher than of N,N′‐dimethyltrifluoromethanesulfonamide. Copyright © 2015 John Wiley & Sons, Ltd.

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A DFT study on nucleophilicity and site selectivity of nitrogen nucleophiles

Cited by 22 publications

References 34 publications

Formation of Acridones by Ethylene Extrusion in the Reaction of Arynes with β-Lactams and Dihydroquinolinones

Formation of Acridones by Ethylene Extrusion in the Reaction of Arynes with β-Lactams and Dihydroquinolinones

Catalytic effect of molecular iodine in Diels–Alder reaction: a density functional theory study

Basicity of trifluoromethylsulfonylformamidines. DFT and FTIR study and NBO analysis

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