Generation and Characterization of the First Persistent Platinum(I)‐Centered Radical

Kratish, Yosi; Kostenko, Arseni; Kaushansky, Alexander; Tumanskii, B. L.; Bravo‐Zhivotovskii, Dmitry; Apeloig, Yitzhak

doi:10.1002/anie.201805107

Cited by 11 publications

(5 citation statements)

References 45 publications

(10 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Platinum Platinum(0) complexes can act as one-electron reductants [281] and react with various alkyl halides by afree radical mechanism. [201,257,258] Even though it is possible to isolate and characterize persistent platinum(I) complexes, [282] their application to trap alkyl radicals has not been well investigated to date. [123c] Along with their use as catalysts in Kharasch additions, [283] Pt complexes also catalyze the radical transformation of alkyl iodides into the corresponding esters under CO atmosphere in the presence of alcohols.…”

Section: Palladiummentioning

confidence: 99%

The Persistent Radical Effect in Organic Synthesis

2019

View full text Add to dashboard Cite

Radical–radical couplings are mostly nearly diffusion‐controlled processes. Therefore, the selective cross‐coupling of two different radicals is challenging and not a synthetically valuable transformation. However, if the radicals have different lifetimes and if they are generated at equal rates, cross‐coupling will become the dominant process. This high cross‐selectivity is based on a kinetic phenomenon called the persistent radical effect (PRE). In this Review, an explanation of the PRE supported by simulations of simple model systems is provided. Radical stabilities are discussed within the context of their lifetimes, and various examples of PRE‐mediated radical–radical couplings in synthesis are summarized. It is shown that the PRE is not restricted to the coupling of a persistent with a transient radical. If one coupling partner is longer‐lived than the other transient radical, the PRE operates and high cross‐selectivity is achieved. This important point expands the scope of PRE‐mediated radical chemistry. The Review is divided into two parts, namely 1) the coupling of persistent or longer‐lived organic radicals and 2) “radical–metal crossover reactions”; here, metal‐centered radical species and more generally longer‐lived transition‐metal complexes that are able to react with radicals are discussed—a field that has flourished recently.

show abstract

Section: Palladiummentioning

confidence: 99%

The Persistent Radical Effect in Organic Synthesis

2019

View full text Add to dashboard Cite

show abstract

“…However, none of the aforementioned signals fit the intense pattern with g || > 2.1 observed in the Ph 3 PbOOH powder. On the other hand, it is well known that radicals centered on adjusted metal ions do show strongly low-field shifted (i.e., large positive g -shifts) EPR signals. , The same origin of the prevalent magnetic species may be supposed for Ph 3 PbOOH. Indeed, the EPR signatures with an anisotropic g -factor larger than 2, recently observed in UV-irradiated PbCl 2 and PbBr 2 crystals, were confidently attributed to the unpaired electron, which interacts with two Pb 2+ ions .…”

Section: Resultsmentioning

confidence: 84%

Triphenyllead Hydroperoxide: A 1D Coordination Peroxo Polymer, Single-Crystal-to-Single-Crystal Disproportionation to a Superoxo/Hydroxo Complex, and Application in Catalysis

et al. 2022

View full text Add to dashboard Cite

The synthesis, transformation, and application in catalysis of triphenyllead hydroperoxide, the first dioxygen lead complex, are described. Triphenyllead hydroperoxide is characterized by 207Pb nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and single-crystal X-ray diffraction, revealing the first one-dimensional (1D) coordination peroxo polymer. Photolytic isomorphous transformation of Ph3PbOOH yields a mixed hydroxo/superoxo crystalline structure, the first nonalkali superoxo crystalline metal salt, which is stable up to 100 °C. Upon further photolysis, another isomorphous transformation of the superoxide to hydroxide is observed. These are the first single-crystal-to-single-crystal hydroperoxide-to-superoxide and then to hydroxide transformations reported to date. Photolysis of triphenyllead hydroperoxide yields two forms of superoxide-doped crystalline structures that are distinguished by widely different characteristic relaxation times. The use of Ph3PbOOH as an easy-to-handle solid two-electron oxidant for the highly enantioselective epoxidation of olefins is described.

show abstract

“…要实现稳态自由基效应, 需满足两个条件: 一是交叉偶联的自由基在体系中产生速率一致, 二是两种自由基的寿命的差别尽可能大. 近年来, 稳态自由基效应在合成化学中得到了较多的应用 [35] II [36] 、Co II [37] 、Fe II [38] 、Ni II [39] 、Cu II [40] 、Pd II [41] 、 Pt I [42] 等.…”

Section: 稳态自由基效应unclassified

Quantitative Thermodynamic and Kinetic Parameters of Radical

Huang¹,

Jia²,

Luo³

et al. 2021

Chinese Journal of Organic Chemistry

View full text Add to dashboard Cite

Radical chemistry has gained its renaissence in the past decade and trendendous progresses have been witnessed in synthetic and material chemistry. However, mechanism studies are largely lagging behind comparing with rapid paces in the development of synthetic methodologies. On the other hand, the study of radical species remains a central theme in physial organic chemistry, and a large amount of thermodynamic and kinetic data on radicals have been generated over a century's reserch. Unfortuately, there has been no systematic compilation and curation of these quatitative data that are dispersedly distributed and buried in literature. As a result, most synthetic chemists are not acquainted with these valuable data. In this review, we aim in compiling and curating thermodynamic and kinetic parameters of radicals, that may hopefully provide a quantitative data basis for rational development and evolution of radical chemistry. The key parameters include radical stability energy (RSE), radical lifetime (τ), substituent constant (σ) and electrophilic index (ω). Fundamental concepts such as radical stability, Class S/O radical substitution effect, persistent/transient radical effect will be discussed on the basis of data.

show abstract

Generation and Characterization of the First Persistent Platinum(I)‐Centered Radical

Abstract: The first persistent platinum(I)-centered radical was generated by homolytic cleavage of a Pt-HgSiR bond of a mercury-substituted platinum(II) complex. The Pt radical was characterized by EPR spectroscopy, chemical trapping experiments, and density functional theory (DFT) calculations.

Cited by 11 publications

References 45 publications

The Persistent Radical Effect in Organic Synthesis

The Persistent Radical Effect in Organic Synthesis

Triphenyllead Hydroperoxide: A 1D Coordination Peroxo Polymer, Single-Crystal-to-Single-Crystal Disproportionation to a Superoxo/Hydroxo Complex, and Application in Catalysis

Quantitative Thermodynamic and Kinetic Parameters of Radical

Contact Info

Product

Resources

About