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   Li, Qingjiang; Guo, Zhongwu (June 2021, Synthesis)

   null (Ed.)

   Abstract Glycosphingolipids (GSLs) are the major vertebrate glycolipids, which contain two distinctive moieties, a glycan and a ceramide, stitched together by a β-glycosidic linkage. The hydrophobic lipid chains of ceramide can insert into the cell membrane to form ‘lipid rafts’ and anchor the hydrophilic glycan onto the cell surface to generate microdomains and function as signaling molecules. GSLs mediate signal transduction, cell interactions, and many other biological activities, and are also related to many diseases. To meet the need of biological studies, chemists have developed various synthetic methodologies to access GSLs. Among them, the application of enzymes to GSL synthesis has witnessed significant advancements in the past decades. This short review briefly summarizes the history and progress of enzymatic GSL synthesis. 1 Introduction 1.1 The Glycosphingolipid Structure 1.2 GSL Biosynthesis 1.3 Functions and Biological Significance 1.4 Overview of GSL Synthesis 1.5 Scope of the Review 2 Glycotransferases for GSL Synthesis 3 Glycosynthases for GSL Synthesis 4 Enzymatic Synthesis of Ceramide 5 Conclusion 

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2. Direct Oxidation of Primary Alcohols to Carboxylic Acids

   https://doi.org/10.1055/s-0040-1706102  

   Cherepakhin, Valeriy; Williams, Travis J. (February 2021, Synthesis)

   null (Ed.)

   Abstract Oxidation of primary alcohols to carboxylic acids is a fundamental transformation in organic chemistry, yet despite its simplicity, extensive use, and relationship to pH, it remains a subject of active research for synthetic organic chemists. Since 2013, a great number of new methods have emerged that utilize transition-metal compounds as catalysts for acceptorless dehydrogenation of alcohols to carboxylates. The interest in this reaction is explained by its atom economy, which is in accord with the principles of sustainability and green chemistry. Therefore, the methods for the direct synthesis of carboxylic acids from alcohols is ripe for a modern survey, which we provide in this review. 1 Introduction 2 Thermodynamics of Primary Alcohol Oxidation 3 Oxometalate Oxidation 4 Transfer Dehydrogenation 5 Acceptorless Dehydrogenation 6 Electrochemical Methods 7 Outlook 

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3. Hypervalent Iodine‐Mediated Azidation Reactions

   https://doi.org/10.1002/ejoc.202200754  

   Mironova, Irina_A; Kirsch, Stefan_F; Zhdankin, Viktor_V; Yoshimura, Akira; Yusubov, Mekhman_S (September 2022, European Journal of Organic Chemistry)

   Abstract Organic azides have found wide application in various fields of science and technology. This review summarizes recently developed approaches to the direct, one‐step synthesis of diverse organic azides utilizing hypervalent iodine reagents. The first part of review deals with the azidation using unstable azidoiodinanes generatedin situfrom common hypervalent iodine reagents (such as diacetoxyiodobenzene or iodosylbenzene) and a source of azide anion (TMSN₃or NaN₃). The second part of review is dedicated to the application of stable azidobenziodoxoles as useful azidating reagents that allow selective direct azidation of C−H bonds or double carbon‐carbon bonds under mild reaction conditions. The use of azidobenziodoxoles eliminates the main disadvantages of the traditional approaches to organic azides, such as the need in pre‐functionalization of organic substrates and harsh reaction conditions. Synthetic application of azidobenziodoxoles made possible direct selective azidation of a plethora of organic substrates including complex molecules at the late synthetic stage. 

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4. Approaches on Ferrofluid Synthesis and Applications: Current Status and Future Perspectives

   https://doi.org/10.1021/acsomega.1c05631  

   Oehlsen, Oscar; Cervantes-Ramírez, Sussy I; Cervantes-Avilés, Pabel; Medina-Velo, Illya A (January 2022, ACS Omega)

   Ferrofluids are colloidal suspensions of iron oxide nanoparticles (IONPs) within aqueous or nonaqueous liquids that exhibit strong magnetic properties. These magnetic properties allow ferrofluids to be manipulated and controlled when exposed to magnetic fields. This review aims to provide the current scope and research opportunities regarding the methods of synthesis of nanoparticles, surfactants, and carrier liquids for ferrofluid production, along with the rheology and applications of ferrofluids within the fields of medicine, water treatment, and mechanical engineering. A ferrofluid is composed of IONPs, a surfactant that coats the magnetic IONPs to prevent agglomeration, and a carrier liquid that suspends the IONPs. Coprecipitation and thermal decomposition are the main methods used for the synthesis of IONPs. Despite the fact that thermal decomposition provides precise control on the nanoparticle size, coprecipitation is the most used method, even when the oxidation of iron can occur. This oxidation alters the ratio of maghemite/magnetite, influencing the magnetic properties of ferrofluids. Strategies to overcome iron oxidation have been proposed, such as the use of an inert atmosphere, adjusting the Fe(II) and Fe(III) ratio to 1:2, and the exploration of other metals with the oxidation state +2. Surfactants and carrier liquids are chosen according to the ferrofluid application to ensure stability. Hence, a compatible carrier liquid (polar or nonpolar) is selected, and then, a surfactant, mainly a polymer, is embedded in the IONPs, providing a steric barrier. Due to the variety of surfactants and carrier liquids, the rheological properties of ferrofluids are an important response variable evaluated when synthesizing ferrofluids. There are many reported applications of ferrofluids, including biosensing, medical imaging, medicinal therapy, magnetic nanoemulsions, and magnetic impedance. Other applications include water treatment, energy harvesting and transfer, and vibration control. To progress from synthesis to applications, research is still ongoing to ensure control of the ferrofluids’ properties. 

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5. Advanced Modeling and Optimization Strategies for Process Synthesis

   https://doi.org/10.1146/annurev-chembioeng-100522-112139  

   Pistikopoulos, Efstratios N; Tian, Yuhe (July 2024, Annual Review of Chemical and Biomolecular Engineering)

   This article provides a systematic review of recent progress in optimization-based process synthesis. First, we discuss multiscale modeling frameworks featuring targeting approaches, phenomena-based modeling, unit operation–based modeling, and hybrid modeling. Next, we present the expanded scope of process synthesis objectives, highlighting the considerations of sustainability and operability to assure cost-competitive production in an increasingly dynamic market with growing environmental awareness. Then, we review advances in optimization algorithms and tools, including emerging machine learning–and quantum computing–assisted approaches. We conclude by summarizing the advances in and perspectives for process synthesis strategies. 

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