We describe herein a highly stereoselective access to Cbz-protected β-enaminones 2 based on the NaOH catalyzed rearrangement of propargylic hydroxylamines 1. The synthetic potential of these β-enaminones is illustrated in an original synthesis of pyrimidines.
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http://dx.doi.org/10.1021/jo301675g | DOI Listing |
J Am Chem Soc
January 2025
Key Laboratory of Chemical Biology of Fujian Province, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China.
Regiodivergent asymmetric synthesis represents a transformative strategy for the efficient generation of structurally diverse chiral products from a single set of starting materials, significantly enriching their enantiomeric composition. However, the design of radical-mediated regiodivergent and enantioselective reactions that can accommodate a wide range of functional groups and substrates has posed significant challenges. The obstacles primarily lie in switching the regioselectivity and achieving high enantiodiscrimination, especially when dealing with high-energy intermediates.
View Article and Find Full Text PDFOrg Lett
January 2025
School of Chemistry, Chemical Engineering, and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore.
Synthetic C-glycosides play a crucial role in molecular biology and medicine. With the surge of interest in C-glycosides and the demand to provide efforts with sufficient feedstock, it is highly significant to pursue novel methodologies to access C-glycosides in a concise and efficient manner. Here, we disclose an attractive strategy that diverges itself from conventional multistep reaction sequences involving the manipulations of protecting groups.
View Article and Find Full Text PDFToxins (Basel)
December 2024
Department of Chemistry, University of Ghana, Legon-Accra P.O. Box LG56, Ghana.
Mycolactone is a complex macrolide toxin produced by , the causative agent of Buruli ulcer. The aim of this paper is to review the chemistry, biosynthetic, and synthetic pathways of mycolactone A/B to help develop an understanding of the mode of action of these polyketides as well as their therapeutic potential. The synthetic work has largely been driven by the desire to afford researchers enough (≥100 mg) of the pure toxins for systematic biological studies toward understanding their very high biological activities.
View Article and Find Full Text PDFChem Rec
December 2024
Qiandongnan Traditional Medicine Research & Development Center, School of Life and Health Science, Kaili University, 3 Kaiyuan Road, Qiandongnan Miao and Dong Autonomous Prefecture, Kaili, 556011, China.
Carbohydrates are natural, renewable, chemical compounds that play crucial roles in biological systems. Thus, efficient and stereoselective glycosylation is an urgent task for the preparation of pure and structurally well-defined carbohydrates. Photoredox catalysis has emerged as a powerful tool in carbohydrate chemistry, providing an alternative for addressing some of the challenges of glycochemistry.
View Article and Find Full Text PDFOrg Lett
December 2024
Strait Institute of Flexible Electronics (SIFE, Future Technologies), Fujian Key Laboratory of Flexible Electronics, Fujian Normal University and Strait Laboratory of Flexible Electronics (SLoFE), Fuzhou 350117, China.
Isothiourea-catalyzed multicomponent cascade reactions are challenging due to the existence of competitive side reactions between multiple reaction partners and intermediates. Herein, we report a practical and efficient protocol for the stereoselective divergent synthesis of pyrazolone-derived β-amino acid esters and β-lactams by isothiourea catalysis. Two distinct reaction pathways are identified, which are controlled by esterification or lactamization of the zwitterionic intermediate.
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