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In the preparation of organolithium reagents, the use of highly activated lithium metal surfaces is essential. Currently, commercially available sources provide high surface area lithium in the form of powders or dispersions. Our group has presented a new approach to synthesize lithium with clean and high surface areas up to 100 times greater than conventional Li-dispersion. Our method involves the use of liquid ammonia (NH3) to effectively clean the lithium surface, resulting in the controlled dendritic growth of lithium structures along the flask wall. This freshly synthesized and highly activated lithium exhibits consistency and reliability, enabling the scalable production of organolithium reagents, ranging from 0.1 mmol to 0.5 mole. Herein, we outline the procedure for applying 5 grams of Li-dendrites in the synthesis of (trimethylsilyl)methylchloride, highlighting the potential impact of our method on organometallic chemistry. 

Archaea produce unique membrane-spanning lipids (MSLs), termed glycerol dialkyl glycerol tetraethers (GDGTs), which aid in adaptive responses to various environmental challenges. GDGTs can be modified through cyclization, cross-linking, methylation, hydroxylation, and desaturation, resulting in structurally distinct GDGT lipids. Here, we report the identification of radical SAM proteins responsible for two of these modifications—a glycerol monoalkyl glycerol tetraether (GMGT) synthase (Gms), responsible for covalently cross-linking the two hydrocarbon tails of a GDGT to produce GMGTs, and a GMGT methylase (Gmm), capable of methylating the core hydrocarbon tail. Heterologous expression of Gms proteins from various archaea inThermococcus kodakarensisresults in the production of GMGTs in two isomeric forms. Further, coexpression of Gms and Gmm produces mono- and dimethylated GMGTs and minor amounts of trimethylated GMGTs with only trace GDGT methylation. Phylogenetic analyses reveal the presence of Gms homologs in diverse archaeal genomes spanning all four archaeal superphyla and in multiple bacterial phyla with the genetic potential to synthesize fatty acid–based MSLs, demonstrating that GMGT production may be more widespread than previously appreciated. We demonstrate GMGT production in three Gms-encoding archaea, identifying an increase in GMGTs in response to elevated temperature in twoArchaeoglobusspecies and the production of GMGTs with up to six rings inVulcanisaeta distributa.The occurrence of such highly cyclized GMGTs has been limited to environmental samples and their detection in culture demonstrates the utility of combining genetic, bioinformatic, and lipid analyses to identify producers of distinct archaeal membrane lipids. 

Herein, we describe the effect of organic solvents on ozone solubility and the rate of ozonolysis reactions using rapid injection NMR spectroscopy. The tabulated solubility and kinetic data allowed for the design of a homogeneous ozonolysis flow reactor capable of delivering precise quantities of dissolved ozone to various olefin substrates.