Olefins from Natural Gas by Oxychlorination

Ethylene and propylene are the key building blocks of the chemical industry, but current processes are unable to close the growing gap between demand and manufacture. Reported herein is an exceptional europium oxychloride (EuOCl) catalyst for the selective (≥95 %) production of light olefins from ethane and propane by oxychlorination chemistry, thus achieving yields of ethylene (90 %) and propylene (40 %) unparalleled by any existing olefin production technology. Moreover, EuOCl is able to process mixtures of methane, ethane, and propane to produce the olefins, thereby reducing separation costs of the alkanes in natural gas. Finally, the EuOCl catalyst was supported on suitable carriers and evaluated in extrudate form, and preserves performance for >150 h under realistic process conditions.     

Halogenbrücken in der Organokatalyse

Halogen bonding is a noncovalent interaction between electrophilic halogen substituents and Lewis bases. Its overall interaction energy is composed of several contributions, namely electrostatics, charge‐transfer and dispersion. This article describes the use of halogen bonding in organocatalysis featuring a test reaction in which the halogen‐based catalyst abstracts chloride from the substrate to form a reactive carbenium species. Other potential modes of activation were ruled out be several comparison experiments.     

Catalytic Reduction of Alkyl and Aryl Bromides Using Propan‐2‐ol

Milstein's complex, (PNN)RuHCl(CO), catalyzes the efficient reduction of aryl and alkyl halides under relatively mild conditions by using propan‐2‐ol and a base. Sterically hindered tertiary and neopentyl substrates are reduced efficiently, as well as more functionalized aryl and alkyl bromides. The reduction process is proposed to occur by radical abstraction/hydrodehalogenation steps at ruthenium. Our research represents a safer and more sustainable alternative to typical silane, lithium aluminium hydride, and tin‐based conditions for these reductions.