α,α′-Diamino-<i>p</i>-tetrafluoroquinodimethane: Stability of One- and Two-Electron Oxidized Species and Fixation of Molecular Oxygen

Mahata, Alok; Chrysochos, Nicolas; Krummenacher, Ivo; Chandra, Sudeshna; Braunschweig, Holger; Schulzke, Carola; Sarkar, Biprajit; Yildiz, Cem B.; Jana, Anukul

doi:10.1021/acs.joc.1c01120

Cited by 8 publications

(5 citation statements)

References 42 publications

(37 reference statements)

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“…MS (LC/MS): m / z = 207 [M + 1] + . The NMR spectroscopic data are in good agreement with those in the literature. , …”

Section: Experimental Partmentioning

confidence: 99%

Latent Carbene in Diaminomethylation of Benzenes: Mechanism and Practical Application

Koidan,

Hurieva,

Rozhenko

et al. 2023

J. Org. Chem.

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Silylformamidine 1 exists in equilibrium with its carbenic form 1′ due to an easy migration of the silyl group. The reaction of 1 with variously substituted fluorobenzenes proceeds as an insertion of the nucleophilic carbene 1′ into the most acidic C−H bond upon mixing the reagents and does not require any catalyst. According to DFT calculations, the classical interpretation of the insertion reaction proceeding via a three-membered transition state structure requires high activation energy. Instead, low activation barriers are predicted for a transfer of the most acidic proton in the aromatic substrate to the carbene carbon. As the next step, a barrierless rearrangement of the formed ion pair toward the product completes the process. The reactivity of substituted benzenes in the reaction with silylformamidine can be roughly assessed by calculated pK a (DMSO) values for the C−H hydrogens. Benzene derivatives having pK a approx. less than 31 can undergo C−H insertion. The reaction provides aminals as the first products, which can easily be transformed into the corresponding aldehydes via acidic hydrolysis. As silylformamidine 1 is tolerant to many functional groups, the reaction can be applied to numerous benzene derivatives, making it a reliable strategy for application in organic synthesis.

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“…MS (LC/MS): m / z = 207 [M + 1] + . The NMR spectroscopic data are in good agreement with those in the literature. , …”

Section: Experimental Partmentioning

confidence: 99%

Latent Carbene in Diaminomethylation of Benzenes: Mechanism and Practical Application

Koidan,

Hurieva,

Rozhenko

et al. 2023

J. Org. Chem.

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“…Ghadwal et al reported imidazol-2-ylidene (saturated N -heterocyclic carbene) and imidazoline-2-ylidene (unsaturated N -heterocyclic carbene) based Thiele and Tschitschibabin hydrocarbons, IIa / IIb and IIIa / IIIb (Scheme ). We reported cyclic(alkyl)-(amino)carbene and monoamino-substituted carbene based Thiele hydrocarbons, IV and V (Scheme ). Also, we reported acyclic diaminocarbene based Thiele and Tschitschibabin hydrocarbons, VIa / VIb (Scheme ).…”

Section: Introductionmentioning

confidence: 99%

Diamidocarbene-Based Thiele and Tschitschibabin Hydrocarbons: Carbonyl Functionalized Kekulé Diradicaloids

et al. 2021

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Herein, we report diamidocarbene (DAC)-based Thiele and Tschitschibabin hydrocarbons, diradicaloids that contain four carbonyl/amido functional groups. The impact of two different π-conjugated spacers, p-phenylene vs p,p′-biphenylene, has been realized. The quantum chemical calculations suggest diamidocarbene (DAC)-based Thiele hydrocarbon (p-phenylene bridged) closed-shell singlet is the ground state, whereas for the diamidocarbene (DAC)-based Tschitschibabin hydrocarbon (p,p′-biphenylene bridged), open-shell singlet is the ground state. The influence of two different π-conjugated spacers also has been reflected in their UV–vis spectra. To gain more information on the diamidocarbene (DAC)-based Thiele and Tschitschibabin hydrocarbons, we have also carried out cyclic voltammetry investigations along with UV–vis–NIR-spectroelectrochemical studies of their corresponding 2-e oxidized product.

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“…Recently, we reported the synthesis and analysis of various carbon center-based open-shell compounds: alkene-derived radical cations, π-conjugated radical cations, radicals, and biradicals . All of these carbon center-based open-shell compounds are mostly unstable in air.…”

Section: Introductionmentioning

confidence: 99%

An Air-Stable Alkene-Derived Organic Radical Cation

et al. 2021

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Alkenes are known to undergo oxidation to radical cations and dications. The radical cations are often highly reactive and not stable under air. Herein, we report the synthesis, isolation, characterization, and molecular structure of an alkene-derived radical cation A, which is stable in air both in the solid state and in solution. The access to this compound was facilitated from E-diamino tri-substituted alkene B as a synthon for the synthesis of A through one-electron oxidation. The E-diamino tri-substituted alkene B was synthesized by the two-electron reduction of N,N′-1,2-propylene-bridged bis-2-phenyl-pyrrolinium cation C. Under two-electron oxidation, alkene B transforms back to cation C involving a double carbocation rearrangement.

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α,α′-Diamino-p-tetrafluoroquinodimethane: Stability of One- and Two-Electron Oxidized Species and Fixation of Molecular Oxygen

Cited by 8 publications

References 42 publications

Latent Carbene in Diaminomethylation of Benzenes: Mechanism and Practical Application

Latent Carbene in Diaminomethylation of Benzenes: Mechanism and Practical Application

Diamidocarbene-Based Thiele and Tschitschibabin Hydrocarbons: Carbonyl Functionalized Kekulé Diradicaloids

An Air-Stable Alkene-Derived Organic Radical Cation

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