A broad range of substituted 2-cyclopentenone derivatives 3-6 are synthesized by the nickel(0)-mediated [3 + 2] cyclization reaction of chromium alkenyl(methoxy)carbene complexes 1 and internal alkynes 2. The reaction takes place with complete regioselectivity with both unactivated alkynes and activated alkynes (electron-withdrawing and electron-donating substituted alkynes). Representative cycloadducts containing boron and tin substituents are further demonstrated to be active partners in classical Pd-catalyzed C-C coupling processes to allow the production of 2-aryl- and 2-alkynyl-substituted cyclopentenones 9-13.
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http://dx.doi.org/10.1021/ja075106+ | DOI Listing |
Nat Chem Biol
January 2025
Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC, USA.
Peptide cyclization is a defining feature of many bioactive molecules, particularly in the ribosomally synthesized and post-translationally modified peptide (RiPP) family of natural products. Although enzymes responsible for N- to C-terminal macrocyclization, lanthipeptide formation or heterocycle installation have been well documented, a diverse array of cyclases have been discovered that perform crosslinking of aromatic side chains. These enzymes form either biaryl linkages between two aromatic amino acids or a crosslink between one aliphatic amino acid and one aromatic amino acid.
View Article and Find Full Text PDFChem Asian J
January 2025
Leibniz-Institut fur Katalyse eV, organmetallic and catalyst, Albert-Einstein-Str. 29a, 18059, Rostock, GERMANY.
Imidazolines play pivotal roles in numerous fields. However, the direct construction of imidazolines from primary amines involves precise C-C and C-N bond formations, rendering this area still underdeveloped to this day. Herein, a photo-driven metal-free catalytic system has been successfully applied to a novel coupling-cyclization reaction between arylamines and formaldehyde, enabling the direct synthesis of various 1,3-diarylimidazolines from primary amines.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Laboratory of Synthesis and Natural Products (LSPN), Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LSPN, BCH 5304, CH-1015 Lausanne, Switzerland.
In the dyotropic rearrangement of molecules with semiflexible structures, characterized by a freely rotating static C-C bond, the formation of a mixture of products is common due to the coexistence of several energetically comparable conformers. Herein, we report that it is possible to modulate the shifting groups by adjusting the metal's coordination sphere in Pd-based dyotropic rearrangement. In the presence of a catalytic amount of Pd(II) salt, the reaction of γ-hydroxyalkenes or γ,δ-dihydroxyalkenes with Selectfluor affords fluorinated tetrahydropyranols or 6,8-dioxabicyclo[3.
View Article and Find Full Text PDFRSC Adv
January 2025
Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences Tehran Iran
Due to the presence of the pyridyl directing group, -aryl-2-aminopyridines can quickly form stable complexes with metals, leading to cyclization and functionalization reactions. A large number of N-heterocycles and nitrogen-based molecules can be easily constructed this direct and atom-economical cross-coupling strategy. In this review, we have highlighted the transformations of -aryl-2-aminopyridines in the presence of various transition metal catalysts, such as palladium, rhodium, iridium, ruthenium, cobalt and copper.
View Article and Find Full Text PDFJ Org Chem
January 2025
College of Chemistry and Environmental Science, Qujing Normal University, Qujing, Yunnan 655011, China.
A novel metal- and azide-free methodology for the synthesis of trifluoromethylated 1,2,3-triazoles from arylamines with a new 3-bromo-1,1,1-trifluoropropan-2-one derived tosylhydrazone has been developed under mild reaction conditions. The new α-bromo-trifluoromethylated tosylhydrazone reagent was operationally safe and bench-stable from low-cost and readily commercially available starting materials in the iodine-promoted aerobic oxidative cycloaddition reaction with arylamines, affording a variety of trifluoromethylated 1,2,3-triazoles in good to excellent yields.
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