Alkyl radical obtained by irradiation of tetrabutylammonium decatungstate in acetonitrile in the presence of cycloalkanes (C5H10, C6H12, C7H14) are efficiently trapped by electrophilic alkenes (acrylonitrile, isopropylydenmalonitrile, isopropylydencyanoacetate) to give the corresponding alkylated aliphatic nitriles. The reaction can be carried out up to complete conversion of the alkene with reasonable (in most cases 60-65 %) yields. Addition of the radicals to the alkene is followed by electron transfer from reduced decatungstate regenerating the sensitizer (turn over number up to 60). Steady-state measurements, EPR evidence, deuteration experiments and attempted intramolecular trapping of the adduct radical support the mechanistic proposal.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/chem.200305285 | DOI Listing |
Comb Chem High Throughput Screen
January 2025
Jiangsu College of Tourism, Yangzhou 225000, P.R. China.
Aims: Organic thiocyanates are important pharmaceutical intermediates. This study aimed to develop a selective and efficient approach for synthesizing organic thiocyanates.
Methods: Under mild reaction conditions, an array of alkenes, KSCN, and diaryliodonium salts are considered good substrates, providing various aryl-substituted alkylthiocyanates with modest to excellent yield.
Org Biomol Chem
January 2025
Department of Chemistry, Faculty of Arts and Sciences, Amasya University, Amasya, Turkey.
Herein, a new metal-free, molecular chlorine-free, environmentally friendly, atom-economical, short time, inexpensive and simple operation method with mild reaction conditions for chlorination of alkenes, cyclic alkenes, ,-unsaturated carbonyl compounds, heteroaromatics, and natural products was reported with up to 96% yields using trichloroisocyanuric acid (TCCA) as the electrophilic chlorine source and TBACl as the nucleophilic chlorine source. It was demonstrated with bicyclic alkene benzonorbornadiene that regioselective chlorobromination and dibromination reactions can be carried out through TCCA/TBABr redox reactions, where TCCA acts as an oxidant in the presence of TBABr. The structures of the redox products were confirmed as a result of control experiments conducted with the newly presented DBI/TBACl and DBI/TBABr halogenation pairs.
View Article and Find Full Text PDFOrg Lett
January 2025
Department of Chemistry, University of Hawai'i at Ma̅noa, Honolulu, Hawaii 96822, United States.
We present a photocatalytic method for alkylamination of alkenes, enabling efficient C-C and C-N bond formation to construct aza-heterocycles valuable in drug discovery. Using a radical-polar crossover pathway, electron-deficient alkenes are reduced to electrophilic radicals, which react with electron-rich alkenes to form nucleophilic radicals. Oxidation of these intermediates yields carbocations, which are trapped by aza-heteroarenes to afford alkylaminated products.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Osaka University: Osaka Daigaku, Department of Applied Chemistry, JAPAN.
Although numerous transition-metal catalyzed cross-coupling reactions of alkenyl electrophiles with a sulfur(VI) leaving group, mainly alkenyl sulfones, have been developed, most rely heavily on highly nucleophilic Grignard reagents, and the use of organoboron reagents remains challenging. We report herein facile preparation and the following Pd-catalyzed Suzuki-Miyaura cross-coupling reaction of alkenyl sulfoximine, a monoaza analog of sulfone. The condensation of alkyl sulfoximine with aldehydes, developed in this study, makes alkenyl sulfoximines more readily available.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
College of Materials, Chemistry & Chemical Engineering, Chengdu University of Technology, Chengdu 610059, China.
Due to the special structure and physicochemical properties of sulfoximines, research on sulfoximines has achieved great progress in recent decades, especially in chemical and medicinal fields. This review highlights recent advancements in the N-functionalization of NH-sulfoximines, focusing on classical cross-coupling reactions with electrophilic agents and oxidative coupling reactions with extensive organic compounds, including specific (hetero)arenes, alkenes (1,4-naphthoquinones), alkanes (cyclohexanes), nucleophiles (thiols, disulfides, sulfinates, diarylphosphine oxides), organyl boronic acids, and arylhydrazines. Transition metal-catalyzed, metal-free, electrochemical and radical oxidative coupling reactions are discussed.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!