Electrochemically driven desaturation of carbonyl compounds

Gnaim, Samer; Takahira, Yusuke; Wilke, Henrik R.; Yao, Zhaohui; Li, Jinjun; Delbrayelle, Dominique; Echeverria, Pierre‐Georges; Vantourout, Julien C.; Baran, Phil S.

doi:10.1038/s41557-021-00640-2

Cited by 62 publications

(46 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Cyclohexanone did not provide the corresponding α-aryl derivative 8k . Instead, partial α-carbonyl desaturation most likely ensued . It is expected that a similar effect would be observed for aryl ketones bearing hydrogens in β-position (e.g., aryl ethyl ketones).…”

Section: Resultsmentioning

confidence: 99%

Electrochemical α-Arylation of Ketones via Anodic Oxidation of In Situ Generated Silyl Enol Ethers

et al. 2021

View full text Add to dashboard Cite

An electrochemical procedure for the α-arylation of ketones has been developed. The method is based on the generation and one-pot anodic oxidation of silyl enol ethers in the presence of the arene. This strategy avoids isolation of the silyl enol intermediate and the utilization of external supporting electrolytes. Intermolecular arylations, which had not been reported so far, are possible when electron-rich arenes are utilized as coupling partners. The method has been demonstrated for a wide variety of aryl ketones and activated arenes, with moderate to good yields (up to 69%) obtained. Mechanistic insights and a theoretical rationale that explains the ketone α-arylation versus dimerization selectivity are also presented.

show abstract

Section: Resultsmentioning

confidence: 99%

Electrochemical α-Arylation of Ketones via Anodic Oxidation of In Situ Generated Silyl Enol Ethers

et al. 2021

View full text Add to dashboard Cite

show abstract

“…From the vantage point of feedstock accessibility and diversity, the direct dehydrogenation of abundant aliphatics can be considered as one of the most attractive olefin-forming reactions . In the past decade, oxidative dehydrogenation of aliphatics bearing acidic weak α-carbonyl C–H bonds has witnessed much progress . By contrast, the dehydrogenation of aliphatics involving neutral or hydridic strong C–H bonds remains elusive, and known reactions in this field rely on two main strategies: catalytic approaches involving transition-metal-mediated C–H activation with an external H-acceptor or oxidant ,− and noncatalytic approaches employing in situ generated radicals as intramolecular H-acceptors (see examples in Figure a and b).…”

Section: Introductionmentioning

confidence: 99%

Site-Selective Acceptorless Dehydrogenation of Aliphatics Enabled by Organophotoredox/Cobalt Dual Catalysis

et al. 2021

View full text Add to dashboard Cite

The value of catalytic dehydrogenation of aliphatics (CDA) in organic synthesis has remained largely underexplored. Known homogeneous CDA systems often require the use of sacrificial hydrogen acceptors (or oxidants), precious metal catalysts, and harsh reaction conditions, thus limiting most existing methods to dehydrogenation of non-or low-functionalized alkanes. Here we describe a visible-light-driven, dual-catalyst system consisting of inexpensive organophotoredox and base-metal catalysts for roomtemperature, acceptorless-CDA (Al-CDA). Initiated by photoexited 2-chloroanthraquinone, the process involves H atom transfer (HAT) of aliphatics to form alkyl radicals, which then react with cobaloxime to produce olefins and H 2 . This operationally simple method enables direct dehydrogenation of readily available chemical feedstocks to diversely functionalized olefins. For example, we demonstrate, for the first time, the oxidant-free desaturation of thioethers and amides to alkenyl sulfides and enamides, respectively. Moreover, the system's exceptional site selectivity and functional group tolerance are illustrated by late-stage dehydrogenation and synthesis of 14 biologically relevant molecules and pharmaceutical ingredients. Mechanistic studies have revealed a dual HAT process and provided insights into the origin of reactivity and site selectivity.

show abstract

“…12,13 However, heterogeneous electrochemical reactions are challenging to understand because electrochemically measured information of current or potential hardly provides chemical information about species under electrochemical reaction. For example, the nature of reaction intermediates, e.g., free radicals, radical ions, ions, often cannot be predicted by electrochemical analysis and requires various control experiments of synthetic scale, 10,[14][15][16] DFT and ab initio calculations, 17,18 or spectroscopic measurement such as electron paramagnetic resonance spectroscopy. 15 Therefore, there are extensive needs for straightforward electroanalytical methods to provide evidences on reaction intermediates and the key parameters which would unveil electrochemical reaction mechanisms.…”

Section: Introductionmentioning

confidence: 99%

Revisiting Thin-Layer Electrochemistry in a Chip-Type Cell for the Study of Electroorganic Reactions

Shin

Kim

et al. 2021

Preprint

View full text Add to dashboard Cite

It is important but challenging to elucidate the electrochemical reaction mechanisms of organic compounds using electroanalytical methods. Particularly, a rapid and straightforward method may be helpful if it can provide information on reaction intermediates or other key electrochemical parameters. In this work, we exploited the advantages of classic thin-layer electrochemistry to develop a thin-layer electroanalysis microchip (TEAM). TEAM provided better resolved voltammetric peaks than under semi-infinite diffusion condition owing to the small height. Importantly, rapid and accurate determination of the number of electrons transferred, n, was enabled by mechanically confining the microliter-scale volume analyte at the electrode, while securing ionic conduction using polyelectrolyte gels. The performance of the TEAM was validated using voltammetry and coulometry of standard redox couples. Utilizing TEAM, a (spectro)electrochemical analysis of FM 1-43, an organic dye widely used in neuroscience, was successfully performed. It was also applied to study the electrochemical oxidation mechanism of pivanilides and alkyltrifluoroborate salts with different substituents and solvents. This work suggests the TEAM as a promising tool to provide invaluable mechanistic information and promote the rational design of electrosynthetic strategies.

show abstract

Electrochemically driven desaturation of carbonyl compounds

Cited by 62 publications

References 40 publications

Electrochemical α-Arylation of Ketones via Anodic Oxidation of In Situ Generated Silyl Enol Ethers

Electrochemical α-Arylation of Ketones via Anodic Oxidation of In Situ Generated Silyl Enol Ethers

Site-Selective Acceptorless Dehydrogenation of Aliphatics Enabled by Organophotoredox/Cobalt Dual Catalysis

Revisiting Thin-Layer Electrochemistry in a Chip-Type Cell for the Study of Electroorganic Reactions

Contact Info

Product

Resources

About