Efficient stereo- and regioselective O-glycosylation methods remain essential to capacitate the studies of sugars and sugar derivatives in various disciplines. In this work, we demonstrated an operationally simple and cost-effective strategy for the synthesis of 1,2-trans glycosides by the activation of armed O-glycosyl trichloroacetimidates donor using zinc tetrafluoroborate. This mild, transition metal-free, and scalable approach allowed stereo- and regioselective synthesis of β-glycosides with a wide range of acceptors containing various protecting groups/functionalities. This method is exemplified by synthesizing a branched trisaccharide fragment related to the cell wall O-polysaccharide of E. Coli O27.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/asia.202400420 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Cobalt-Catalyzed Hydroglycosylation of Alkynes for the Synthesis of Vinyl α-C-Glycosides.
Angew Chem Int Ed Engl
January 2025
Sichuan University, State Key Laboratory of Biotherapy, CHINA.
Herein we report a cobalt-catalyzed hydroglycosylation of terminal alkynes, employing bench-stable ortho-iodobiphenyl (oIB) substituted sulfides as glycosyl donors. This reaction occurs with high stereo- and regioselectivity to afford E-configured vinyl α-C-glycosides, a class of compounds nontrivial to access by previous methods. The use of a bis(oxazoline) ligand with bulky side chains is critical for the high selectivities observed.
View Article and Find Full Text PDFAccess to fluorinated dienes through hydrofluorination of 2-En-4-ynoates.
Org Chem Front
December 2024
Department of Chemistry, University of Pittsburgh Pittsburgh Pennsylvania 15260 USA
Article Synopsis
- The hydrofluorination of enynoates allows for the efficient synthesis of fluorinated dienoates using a pyridinium tetrafluoroborate salt.
- This method effectively converts various aryl-substituted enynoates into the desired fluorinated products with significant control over their stereochemistry and regioselectivity.
- Mechanistic studies were performed to understand the reaction process better and to optimize the outcomes based on different reaction conditions.
Chemodivergent, enantio- and regioselective couplings of alkynes, aldehydes and silanes enabled by nickel/N-heterocyclic carbene catalysis.
Sci Bull (Beijing)
December 2024
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China. Electronic address:
Divergent synthesis of valuable molecules through common starting materials and metal catalysis represents a longstanding challenge and a significant research goal. We here describe chemodivergent, highly enantio- and regioselective nickel-catalyzed reductive and dehydrogenative coupling reactions of alkynes, aldehydes, and silanes. A single chiral Ni-based catalyst is leveraged to directly prepare three distinct enantioenriched products (silyl-protected trisubstituted chiral allylic alcohols, oxasilacyclopentenes, and silicon-stereogenic oxasilacyclopentenes) in a single chemical operation.
View Article and Find Full Text PDFPd-Catalyzed [2 + 2 + 2] Cyclization of Alkyne-cyclohexadienones and -Akynyl Benzenesulfonamides for Construction of Fused Tricyclic Hydronaphthofurans.
J Org Chem
January 2025
State Key Laboratory of Antiviral Drugs, Pingyuan Laboratory, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang 453007, Henan, China.
A palladium-catalyzed [2 + 2 + 2] cyclization of 1,6-enynes with unsymmetrical alkynes has been successfully accomplished, resulting in the formation of a series of fused tricyclic hydronaphthofurans with high stereo- and regioselectivity in a single step. This reaction demonstrates 100% atomic economy and exhibits a broad substrate scope.
View Article and Find Full Text PDFConvergent Total Synthesis of Kalmanol.
Angew Chem Int Ed Engl
November 2024
State Key Laboratory of Applied Organic Chemistry and College of Chemistry and Chemical Engineering, Lanzhou University, 222 South Tianshui Road, Lanzhou, Gansu Province, 730000, China.
Kalmanol (1) is the first isolated kalmane-type grayanoid featuring a highly oxidized 5/8/5/5 tetracyclic carbon skeleton and 9 contiguous stereocenters. We have accomplished the efficient and asymmetric total synthesis of 1 in 16 steps from known compounds (20 steps from commercially available starting materials) by a modular synthetic strategy. A tetracyclic intermediate was prepared in a convergent manner through a Grignard reaction and a subsequent ring-closing metathesis reaction of two enantiomerically enriched fragments.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!