Asymmetric nucleophilic monofluoroalkylation of a broad range of aldehydes with an α-fluoro-γ-sulfinylbenzyl carbanion takes place with complete control of the facial selectivity at the carbanion and good to high anti-diastereoselectivity to give easily separable mixtures of two optically pure 1,2-fluorohydrin derivatives (up to 24:1 anti/syn). Separation and removal of the p-tolylsulfinyl group with tBuLi provides enantiomerically pure anti-1,2-disubstituted-1,2-fluorohydrins, whereas α-fluorobenzylketones can be obtained by desulfinylation of the mixture followed by pyridinium chlorochromate oxidation (one-pot process).
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http://dx.doi.org/10.1002/chem.201103919 | DOI Listing |
Org Lett
January 2025
Department of Chemistry, Graduate School of Science, Osaka Metropolitan University, 3-3-138 Sumiyoshi-ku, Osaka 558-8585, Japan.
The asymmetric total synthesis of isolinearol, a -dolastane-type diterpenoid that inhibits byssal thread formation by mussels, has been achieved. In the synthesis, the key features include an intramolecular reductive nucleophilic addition using a low-valence titanium species and the direct installation of a ketone side chain. We evaluated their biological activities using the synthetic samples and found the novel inhibitory molecules with a simplified structure exhibit high inhibitory activities against byssus formation and low toxicities.
View Article and Find Full Text PDFMolecules
January 2025
GSK Carbon Neutral Laboratories for Sustainable Chemistry, Jubilee Campus, University of Nottingham, Triumph Road, Nottingham NG7 2TU, UK.
The range of chemical databases available has dramatically increased in recent years, but the reliability and quality of their data are often negatively affected by human-error fidelity. The size of chemical databases can make manual data curation/checking of such sets time consuming; thus, automated tools to help this process are highly desirable. Herein, we propose the use of Graph Neural Networks (GNNs) to identifying potential stereochemical misassignments in the primary asymmetric catalysis literature.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 München, Germany.
Free ions in organic solvents of low polarity would be valuable tools for the activation of low-reactivity substrates. However, the formation of unreactive ion pairs at concentrations relevant for synthesis has prevented the success of this concept so far. On the example of highly nucleophilic pyridinamide phosphonium salts in dichloromethane, we show that asymmetric aggregation offers a solution to this general problem.
View Article and Find Full Text PDFChemistry
January 2025
University of Padova: Universita degli Studi di Padova, Dipartimento di Scienze Chimiche, Via Marzolo 1, 35131, Padova, ITALY.
Chalcogenide exchange reactions are an important class of bimolecular nucleophilic substitution reactions (SN2) involving sulfur and selenium species as nucleophile, central atom, and/or leaving group, which are fundamental throughout redox biology and metabolism. While thiol-disulfide exchange reactions have been deeply investigated, those involving selenium are less understood, especially with regards to the polarised selenenyl sulfides RSe-SR' even though the directed reactivity of selenenyl sulfides is biologically crucial for selenoenzymes such as thioredoxin reductase (TrxR) and glutathione peroxidase (GPx). Synthetic methods to create asymmetric selenenyl sulfides with high regiochemical purity only emerged over the last five years; this functional group has already demonstrated powerful applications to cell biology, through probes for molecular imaging (e.
View Article and Find Full Text PDFNat Commun
January 2025
College of Chemistry and Life Science, Advanced Institute of Materials Science, Changchun University of Technology, Changchun, P. R. China.
The enantioselective domino Heck/cross-coupling has emerged as a powerful tool in modern chemical synthesis for decades. Despite significant progress in relative rigid skeleton substrates, the implementation of asymmetric Heck/cross-coupling cascades of highly flexible haloalkene substrates remains a challenging and and long-standing goal. Here we report an efficient asymmetric domino Heck/Tsuji-Trost reaction of highly flexible vinylic halides with 1,3-dienes enabled by palladium catalysis.
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