After optimization for retention of catalytic activity, 4-chlorobenzoic acid emerged as the optimal catalyst for the aliphatic ketone Claisen rearrangement. The optimal catalyst enables a one-pot, metal-free, catalytic protocol from allylic alcohols to γ,δ-unsaturated ketones. The optimized process tolerates a range of substrates, including substituents with acid-labile protecting groups. Reaction monitoring and DFT studies of the aliphatic ketone Claisen process agree that the ultimate rearrangement step typically has the highest activation barrier.
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http://dx.doi.org/10.1002/chem.202402371 | DOI Listing |
Foods
November 2024
Department of Food Engineering, Faculty of Agriculture, Atatürk University, 25240 Erzurum, Türkiye.
The aim of this study was to determine the effects of ripening rate (slow or fast), usage autochthonous starter cultures (control-spontaneous fermentation, GM77, GM92 or GM77 + GM92) and type of fat (beef fat-BF, sheep tail fat-STF and BF+STF) on the volatile compounds of sucuk (a Turkish dry fermented sausage). A total of 74 volatile compounds were identified, including groups of aliphatic hydrocarbons, aldehydes, ketones, alcohols, sulfide compounds, esters, aromatic hydrocarbons, nitrogenous compounds, acids and terpenes in sucuk. Slow ripening resulted in significant increases in the abundance of ethanol, acetic acid, ethyl acetate, acetoin and diacetyl.
View Article and Find Full Text PDFChemistry
December 2024
State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, 730000, Lanzhou, China.
The application of biocatalysts in organic synthesis has grown significantly in recent years, and both academia and industry are continuously searching for novel biocatalysts capable of performing challenging chemical reactions. Mushrooms are a rich source of ligninolytic and secondary metabolite biosynthetic enzymes, and therefore were considered promising biocatalysts for organic synthesis. This review focuses on the broad utilization potential of mushroom-based biocatalysts and highlights key advances in mushroom-mediated redox reactions.
View Article and Find Full Text PDFOrg Lett
December 2024
College of Chemistry, School of Life Sciences, Zhengzhou University, Zhengzhou, Henan 450001, China.
Condition-controlled switchable and divergent transformations of cost-effective 2-bromo-3,3,3-trifluoropropene (BTP) and aldehydes were realized using a decatungstate (TBADT)-photocatalyzed strategy. The hydroacylated products, i.e.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
State Key Laboratory of Structural Chemistry, Center for Excellence in Molecular Synthesis, Fujian Institute of Research on the Structure of Matter, University of Chinese Academy of Sciences, Fuzhou 350100, China.
Asymmetric transfer hydrogenation (ATH) has been recognized as a highly valuable strategy that allows access to enantioenriched substances and has been widely applied in the industrial production of drug molecules. However, despite the great success in ATH of ketones, highly efficient, regio- and stereoselective ATH on enones remains underdeveloped. Moreover, optically pure acyloins and 1,2-diols are both extremely useful building blocks in organic synthesis, medicinal chemistry, and materials science, but concise asymmetric approaches allowing access to different types of acyloins and 1,2-diols have scarcely been discovered.
View Article and Find Full Text PDFFree Radic Res
November 2024
Faculty of Chemistry, Belarusian State University, Minsk, Belarus.
Free radicals are ubiquitous in biological systems, being responsible for pathogenesis of degenerative diseases and participating in vitally important biochemical processes, which are mediated by radical regulatory agents. The effects of the aliphatic amine substituents in the catechol-derived Mannich bases on their antioxidant and pro-oxidant activity were investigated. It has been found that the presence of catechol moiety in the structure of Mannich bases allows them to act as Cu(II) reductants, efficient Fe(II) chelators and potent DPPH radical scavengers.
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