Divergent Electrolysis for the Controllable Coupling of Thiols with 1,2-Dichloroethane: a Mild Approach to Sulfide and Sulfoxide

Vicinal dibromides and dichlorides are important commodity chemicals and indispensable synthetic intermediates in modern chemistry that are traditionally synthesized using hazardous elemental chlorine and bromine. Meanwhile, the environmental persistence of halogenated pollutants necessitates improved approaches to accelerate their remediation. Here, we introduce an electrochemically assisted shuttle (e-shuttle) paradigm for the facile and scalable interconversion of alkenes and vicinal dihalides, a class of reactions that can be used both to synthesize useful dihalogenated molecules from simple alkenes and to recycle waste material through retro-dihalogenation. The reaction is demonstrated using 1,2-dibromoethane, as well as 1,1,1,2-tetrachloroethane or 1,2-dichloroethane, to dibrominate or dichlorinate, respectively, a wide range of alkenes in a simple setup with inexpensive graphite electrodes. Conversely, the hexachlorinated persistent pollutant lindane could be fully dechlorinated to benzene in soil samples using simple alkene acceptors.

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Alkene Polymerization Reactions with Transition Metal Catalysts

10.1016/s0167-2991(07)x0001-6 ◽

2007 ◽

Keyword(s):

Transition Metal ◽

Metal Catalysts ◽

Transition Metal Catalysts ◽

Alkene Polymerization

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EXTENDING TABLETOP XUV SPECTROSCOPY TO THE LIQUID PHASE TO EXAMINE TRANSITION METAL CATALYSTS

Proceedings of the 72nd International Symposium on Molecular Spectroscopy ◽

10.15278/isms.2017.ri07 ◽

2017 ◽

Author(s):

Kristin Benke ◽

Josh Vura-Weis ◽

Elizabeth Ryland

Keyword(s):

Liquid Phase ◽

Transition Metal ◽

Metal Catalysts ◽

Transition Metal Catalysts ◽

Xuv Spectroscopy

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A study on naming motivation of new words of chemical element in modern chemistry translations

Han-Character and Classical written language Education ◽

10.15670/hace.2013.31.1.249 ◽

2013 ◽

Vol 31 (0) ◽

pp. 249-266

Author(s):

Li Li ◽

Keyword(s):

Chemical Element ◽

New Words ◽

Modern Chemistry

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Copper Catalyzed sp3 C-H α-Acetylation

10.26434/chemrxiv.11407116.v1 ◽

2019 ◽

Author(s):

Otome Okoromoba ◽

Eun Sil Jang ◽

Claire McMullin ◽

Thomas Cundari ◽

Timothy H. Warren

Keyword(s):

Natural Products ◽

Dft Studies ◽

Alkyl Radicals ◽

Important Chemical ◽

Alkyl Electrophiles ◽

Synthetic Intermediates ◽

Alkylation Reactions

α-substituted ketones are important chemical targets as synthetic intermediates as well as functionalities in in natural products and pharmaceuticals. We report the sp3 C-H α-acetylation of sp3 C-H substrates R-H with arylmethyl ketones ArC(O)Me to provide α-alkylated ketones ArC(O)CH2R at RT with tBuOOtBu as oxidant via copper(I) β-diketiminato catalysts. Proceeding via alkyl radicals R•, this method enables α-substitution with bulky substituents without competing elimination that occurs in more traditional alkylation reactions between enolates and alkyl electrophiles. DFT studies suggest the intermediacy of copper(II) enolates [CuII](CH2C(O)Ar) that capture alkyl radicals R• to give R-CH2C(O)Ar under competing dimerization of the copper(II) enolate to give the 1,4-diketone ArC(O)CH2CH2C(O)Ar.

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Copper Catalyzed sp3 C-H α-Acetylation

10.26434/chemrxiv.11407116 ◽

2019 ◽

Author(s):

Otome Okoromoba ◽

Eun Sil Jang ◽

Claire McMullin ◽

Thomas Cundari ◽

Timothy H. Warren

Keyword(s):

Natural Products ◽

Dft Studies ◽

Alkyl Radicals ◽

Important Chemical ◽

Alkyl Electrophiles ◽

Synthetic Intermediates ◽

Alkylation Reactions

α-substituted ketones are important chemical targets as synthetic intermediates as well as functionalities in in natural products and pharmaceuticals. We report the sp3 C-H α-acetylation of sp3 C-H substrates R-H with arylmethyl ketones ArC(O)Me to provide α-alkylated ketones ArC(O)CH2R at RT with tBuOOtBu as oxidant via copper(I) β-diketiminato catalysts. Proceeding via alkyl radicals R•, this method enables α-substitution with bulky substituents without competing elimination that occurs in more traditional alkylation reactions between enolates and alkyl electrophiles. DFT studies suggest the intermediacy of copper(II) enolates [CuII](CH2C(O)Ar) that capture alkyl radicals R• to give R-CH2C(O)Ar under competing dimerization of the copper(II) enolate to give the 1,4-diketone ArC(O)CH2CH2C(O)Ar.

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Synthesis of Nitrile-Bearing Quaternary Centers via an Equilibrium-Driven Transnitrilation and Anion-Relay Strategy

10.26434/chemrxiv.7834940 ◽

2019 ◽

Author(s):

Sebastien Alazet ◽

Michael West ◽

Purvish Patel ◽

Sophie Rousseaux

Keyword(s):

Building Blocks ◽

One Pot ◽

Quaternary Centers ◽

Synthetic Intermediates

The efficient preparation of nitrile-containing building blocks is of interest due to their utility as synthetic intermediates and their prevalence in pharmaceuticals. As a result, significant efforts have been made to develop methods to access these motifs which rely on safer and non-toxic sources of CN. Herein, we report that 2-methyl-2-phenylpropanenitrile is an efficient, non-toxic, electrophilic CN source for the synthesis of nitrile-bearing quaternary centers via a thermodynamic transnitrilation and anion-relay strategy. This one-pot process leads to nitrile products resulting from the gem-difunctionalization of alkyl lithium reagents.

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Renewable Diesel Blendstocks and Biopriviliged Chemicals Distilled from Algal Biocrude Oil Converted via Hydrothermal Liquefaction

10.26434/chemrxiv.9630695 ◽

2019 ◽

Author(s):

Wan-Ting (Grace) Chen ◽

Zhenwei Wu ◽

Buchun Si ◽

Yuanhui Zhang

Keyword(s):

Oxidation Stability ◽

Ash Content ◽

Hydrothermal Liquefaction ◽

Fractional Distillation ◽

Chemical Compositions ◽

Steam Temperature ◽

Renewable Diesel ◽

Commodity Chemicals ◽

Biocrude Oil ◽

Specification Analysis

This study aims to produce renewable diesel and biopriviliged chemicals from microalgae that can thrive in wastewater environment. Spirulina (SP) was converted into biocrude oil at 300ºC for a 30-minute reaction time via hydrothermal liquefaction (HTL). Next, fractional distillation was used to separate SP-derived biocrude oil into different distillates. It was found that 62% of the viscous SP-derived biocrude oil can be separated into liquids at about 270ºC (steam temperature of the distillation). Physicochemical characterizations, including density, viscosity, acidity, elemental compositions, higher heating values and chemical compositions, were carried out with the distillates separated from SP-derived biocrude oil. These analyses showed that 15% distillates could be used as renewable diesel because they have similar heating values (43-46 MJ/kg) and carbon numbers (ranging from C8 to C18) to petroleum diesel. The Van Krevelan diagram of the distillates suggests that deoxygenation was effectively achieved by fractional distillation. In addition, GC-MS analysis indicates that some distillates contain biopriviliged chemicals like aromatics, phenols and fatty nitriles that can be used as commodity chemicals. An algal biorefinery roadmap was proposed based on the analyses of different distillates from the SP-derived biocrude oil. Finally, the fuel specification analysis was conducted with the drop-in renewable diesel, which was prepared with 10 vol.% (HTL10) distillates and 90 vol.% petroleum diesel. According to the fuel specification analysis, HTL10 exhibited a qualified lubricity (<520 µm), acidity (<0.3 mg KOH/g) and oxidation stability (>6 hr), as well as a comparable net heat of combustion (1% lower), ash content (29% lower) and viscosity (17% lower) to those of petroleum diesel. Ultimately, it is expected that this study can provide insights for potential application of algal biocrude oil converted via HTL.

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