A Pd-catalyzed asymmetric higher-order dipolar cycloaddition between allenyl carbonates and azadienes is achieved by exploiting novel alkylidene-π-allyl-Pd dipoles. This research provides a modular platform for the synthesis of challenging chiral endocyclic allenes bearing a medium-sized heterocyclic motif and a centrally chiral stereocenter in good yields with high enantio- and diastereoselectivities (29 examples, up to 97% yield, 97:3 er and >19:1 dr). Experimental and computational studies elucidate the possible reaction mechanism and the observed stereochemical results. Based on the mechanistic understanding, a new π-propargyl-Pd dipole was designed to further extend the success of the higher order dipolar cycloaddition strategy to the synthesis of 10-membered endocyclic alkynes from propargyl carbonates and azadienes (13 examples, up to 98% yield and 94.5:5.5 er).
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http://dx.doi.org/10.1021/jacs.4c10328 | DOI Listing |
J Am Chem Soc
January 2025
State Key Laboratory of Applied Organic Chemistry & College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China.
The cycloaddition of aziridines with unsaturated compounds is a valuable method for synthesizing nitrogen heterocycles. However, this process is predominantly substrate-controlled, posing significant challenges in regulating the regioselectivity of the C-N bond cleavage. In this study, we report a nickel-catalyzed dynamic kinetic activation strategy that enables catalyst-controlled activation of aziridines.
View Article and Find Full Text PDFJ Org Chem
January 2025
Department of Medical Chemistry, Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614 Poznań, Poland.
There has been a long search for a simple preparation of new cyclic analogues of ionophore antibiotics. We report a simple and general synthesis of three new cyclic derivatives of polyether ionophore, monensin A (MON). The application of the Huisgen 1,3-dipolar cycloaddition of azides and terminal alkynes to macrocyclization results in a concise, synthetic route to monensin lacton or lactam in only 4 steps.
View Article and Find Full Text PDFMacromol Rapid Commun
January 2025
Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, 657-8501, Japan.
Here, "direct click bonding" of solid materials is proposed, which is the direct bonding of solid surfaces via the formation of covalent bonds without any adhesive. The present study shows that the Cu-free Huisgen 1,3-dipolar cycloaddition reaction proceeds between solid surfaces displaying cyclooctyne and azide groups, and it achieved the strong bonding of dissimilar solid materials as a macroscopic reaction. The bonding strength obtained is sufficiently high for practical use, and the strength can be controlled by the surface density of the cyclooctyne groups.
View Article and Find Full Text PDFChem Biodivers
January 2025
Matrusri Education Society, Department of Sciences and Humanities, Matrusri Engineering College, Hyderabad, 500059, Hyderabad, INDIA.
In this work, we have adopted an easy route to synthesizing bis-1,2,3-triazole-based benzophenone compounds via a 1,3-dipolar cycloaddition reaction (Click Chemistry). All the target compounds achieved better yields though the microwave-assisted method than the conventional method. Target compounds structure were confirmed based on the IR, 1H NMR, 13C NMR and HR Mass analysis.
View Article and Find Full Text PDFPharmaceuticals (Basel)
November 2024
Laboratory of Nanobiotechnologies, Saint-Petersburg National Research Academic University of the Russian Academy of Sciences, Saint Petersburg 194021, Russia.
: A series of spiro-fused heterocyclic compounds containing cyclopropa[a]pyrrolizidine-2,3'-oxindole and 3-spiro[3-azabicyclo[3.1.0]-hexane]oxindole frameworks were synthesized and studied for their in vitro antiproliferative activity against human erythroleukemia (K562), cervical carcinoma (HeLa), acute T cell leukemia (Jurkat), melanoma (Sk-mel-2) and breast cancer (MCF-7) as well as mouse colon carcinoma (CT26) cell lines.
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