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1. Mechanistic insight into initiation and regioselectivity in the copolymerization of epoxides and anhydrides by Al complexes

   https://doi.org/10.1039/D0CC05652A  

   Popowski, Yanay; Moreno, Juan J.; Nichols, Asa W.; Hooe, Shelby L.; Bouchey, Caitlin J.; Rath, Nigam P.; Machan, Charles W.; Tolman, William B. (November 2020, Chemical Communications)

   null (Ed.)

   Pentacoordinate Al catalysts comprising bipyridine (bpy) and phenanthroline (phen) backbones were synthesized and their catalytic activity in epoxide/anhydride copolymerization was investigated and compared to ( t-Bu salph)AlCl. Stoichiometric reactions of tricyclic anhydrides with Al alkoxide complexes produced ring-opened products that were characterized by NMR spectroscopy, mass spectrometry, and X-ray crystallography, revealing key regio- and stereochemical aspects. 

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2. Fischer-tropsch synthesis of fuels and olefins in 3D printed SS microreactor using iron/graphene oxide catalysts with Mn- and Na-metal promoters

   Hassan, S; Arslan, M; Shajahan, J; Bepari, S; Vidanapathirana, P; Kuila, D (May 2024, System)

   The effects of adding Mn and Na promoter metals to graphene oxide (GO)-supported iron-based catalysts for Ficher-Tropsch Synthesis (FTS) reactions to olefins at 20 bars were investigated in a 3D-printed stainless steel (SS) Microreactor. While promoter metals encourage reduction of iron oxide to iron to form iron carbide, the active metal catalysts in GO allow hydrogenation of CO. These catalysts were synthesized by layer deposition method and characterized by different techniques. The TEM images show the integration of graphene oxide into the catalysts. The XRD and XPS studies confirmed the crystal structure and oxidation states of the metals. The catalytic activity and product selectivity were studied in the temperature range of 200–350°Cwith a 2:1 M ratio of H2: CO. Higher CO conversion with greater selectivity for olefins was observed in the presence of the promoters. FeMnNa@GO showed better stability than both Fe@GO and FeMn@GO catalysts in time-on-stream studies. 

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3. Chemoselective, Scalable Nickel‐Electrocatalytic O ‐Arylation of Alcohols

   https://doi.org/10.1002/anie.202107820  

   Zhang, Hai‐Jun; Chen, Longrui; Oderinde, Martins S.; Edwards, Jacob T.; Kawamata, Yu; Baran, Phil S. (August 2021, Angewandte Chemie International Edition)

   Abstract The formation of aryl‐alkyl ether bonds through cross coupling of alcohols with aryl halides represents a useful strategic departure from classical S_N2 methods. Numerous tactics relying on Pd‐, Cu‐, and Ni‐based catalytic systems have emerged over the past several years. Herein we disclose a Ni‐catalyzed electrochemically driven protocol to achieve this useful transformation with a broad substrate scope in an operationally simple way. This electrochemical method does not require strong base, exogenous expensive transition metal catalysts (e.g., Ir, Ru), and can easily be scaled up in either a batch or flow setting. Interestingly, e‐etherification exhibits an enhanced substrate scope over the mechanistically related photochemical variant as it tolerates tertiary amine functional groups in the alcohol nucleophile. 

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4. Iron( iii ) chloride-catalyzed activation of glycosyl chlorides

   https://doi.org/10.1039/C8OB02413H  

   Geringer, Scott A.; Demchenko, Alexei V. (December 2018, Organic & Biomolecular Chemistry)

   Glycosyl chlorides have historically been activated using harsh conditions and/or toxic stoichiometric promoters. More recently, the Ye and the Jacobsen groups showed that glycosyl chlorides can be activated under organocatalytic conditions. However, those reactions are slow, require specialized catalysts and high temperatures, but still provide only moderate yields. Presented herein is a simple method for the activation of glycosyl chlorides using abundant and inexpensive ferric chloride in catalytic amounts. Our preliminary results indicate that both benzylated and benzoylated glycosyl chlorides can be activated with 20 mol% of FeCl 3 . 

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5. Iron‐Catalyzed Cross‐Couplings in the Synthesis of Pharmaceuticals: In Pursuit of Sustainability

   https://doi.org/10.1002/anie.201800364  

   Piontek, Aleksandra; Bisz, Elwira; Szostak, Michal (July 2018, Angewandte Chemie International Edition)

   Abstract The scarcity of precious metals has led to the development of sustainable strategies for metal‐catalyzed cross‐coupling reactions. The establishment of new catalytic methods using iron is attractive owing to the low cost, abundance, ready availability, and very low toxicity of iron. In the last few years, sustainable methods for iron‐catalyzed cross‐couplings have entered the critical area of pharmaceutical research. Most notably, iron is one of the very few metals that have been successfully field‐tested as highly effective base‐metal catalysts in practical, kilogram‐scale industrial cross‐couplings. In this Minireview, we critically discuss the strategic benefits of using iron catalysts as green and sustainable alternatives to precious metals in cross‐coupling applications for the synthesis of pharmaceuticals. The Minireview provides an essential introduction to the fundamental aspects of practical iron catalysis, highlights areas for improvement, and identifies new fields to be explored. 

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