An interesting stereo- and chemoselective cyclization reaction of several N-sulfonyl ketimines as C/N-donors with a variety of α,β-unsaturated sulfonyl fluorides promoted by DBU is reported. This substrate-dependent selective C-C vs. C-N bond cyclization process leads to important classes of trans-cyclopropane and fused dihydropyrrole scaffolds in satisfactory yields with excellent diastereoselectivities (dr up to ≤99 : 1). High-yield single-stage synthesis of biologically interesting sulfamate-fused-pyrrole and 2-pyrrolyl phenol derivatives was successfully established.
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http://dx.doi.org/10.1039/c9ob00433e | DOI Listing |
Org Lett
January 2025
School of Pharmacy, Yantai University, Yantai 264005, P. R. China.
Compared with the energetically favorable 5- or 6-membered fluoro-functionalized heterocycles, the construction of medium-sized fluoro-heterocycles is relatively under-researched because of their inherently unfavorable enthalpic and entropic nature. Based on rational design and DFT calculations, a novel photocatalytic difluoromethyl radical-initiated intramolecular 7--trig cyclization was realized, thus affording a sustainable route for the synthesis of challenging fluoro-functionalized medium-sized -heterocycles. Depending on atomic dipole moment corrected Hirshfeld population (ADCH) charge calculations, the chemoselective 6--trig radical cyclizations were further replenished.
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 PDFOrg Lett
January 2025
College of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China.
Capturing CO is highly valued in the field of organic synthesis, especially underdeveloped dual-CO conversion. In this study, we detail a novel reductive cyclization of 2-indolylanilines with dual CO as a difunctional reagent in the presence of PMHS [poly(methylhydrosiloxane)], delivering methyl-substituted quinoxalines. Furthermore, another chemoselective cyclization with 2-pyrrolylanilines is also realized by converting mono-CO.
View Article and Find Full Text PDFJ Org Chem
January 2025
State Key Laboratory of Macromolecular Drugs and Large-Scale Manufacturing, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, P. R. China.
The Pd-catalyzed multicomponent tandem reaction of β-ketonitriles, arylboronic acids and DMSO was efficiently developed, enabling access to a variety of poly substituted pyridines. The protocol shows excellent chemoselectivity, generating nicotinonitriles or symmetrical tetrasubstituted pyridines under different conditions by tandem cyclization of enaminone intermediates with β-ketonitriles or enolates, respectively, and does not require extra ammonias. This method boasts notable advantages, such as the use of commercially available or easily prepared substrates, simple conditions, a broad substrate scope, and good functional group tolerance.
View Article and Find Full Text PDFOrg Biomol Chem
January 2025
Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology (ECUST), Shanghai 200237, China.
A highly efficient base-controlled synthesis of -β-trifluoromethyl-substituted 2-benzo[]imidazole-2-thiones and 2-fluoro-4-benzo[4,5]imidazo[2,1-][1,3]thiazines hydroamination or defluorinative cyclizations of α-(trifluoromethyl)styrenes with 2-mercaptobenzimidazole was developed.
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