Access to Aryl and Heteroaryl Trifluoromethyl Ketones from Aryl Bromides and Fluorosulfates with Stoichiometric CO
作者:Martin B. Johansen、Oliver R. Gedde、Thea S. Mayer、Troels Skrydstrup
DOI:10.1021/acs.orglett.0c01117
日期:2020.6.5
trifluoromethyl ketones starting from readily accessible aryl bromides and fluorosulfates, the latter easily prepared from the corresponding phenols. The methodology utilizes low pressure carbon monoxide generated ex situ from COgen to generate Weinreb amides as reactive intermediates that undergo monotrifluoromethylation affording the corresponding aromatic trifluoromethyl ketones (TFMKs) in good
Radical Carbonyl Umpolung Arylation via Dual Nickel Catalysis
作者:Huan-Ming Huang、Peter Bellotti、Johannes E. Erchinger、Tiffany O. Paulisch、Frank Glorius
DOI:10.1021/jacs.1c12199
日期:2022.2.2
This redox-neutral approach provides a complementary method to construct Grignard-type products from (hetero)aryl bromides and aliphaticaldehydes, without the need for pre-functionalization. A sequential activation, hydrogen-atom transfer, and halogen atom transfer process could directly convert aldehydes to the corresponding ketyl-type radicals, which further react with aryl-nickel intermediates in
synthesized and evaluated for their antibacterial activity against Gram-positive Staphylococcus aureus and Bacillus subtilis and Gram-negative Escherichia coli and in vitro antifungal activity against Candida albicans and Aspergillus niger. The results of antimicrobial activity demonstrated that the compounds 10, 20, and 21 were the most active ones among the synthesized compounds. The QSAR studies revealed
Amide Synthesis by Nickel/Photoredox‐Catalyzed Direct Carbamoylation of (Hetero)Aryl Bromides
作者:Nurtalya Alandini、Luca Buzzetti、Gianfranco Favi、Tim Schulte、Lisa Candish、Karl D. Collins、Paolo Melchiorre
DOI:10.1002/anie.202000224
日期:2020.3.23
Herein, we report a one‐electron strategy for catalytic amide synthesis that enables the direct carbamoylation of (hetero)aryl bromides. This radical cross‐coupling approach, which is based on the combination of nickel and photoredox catalysis, proceeds at ambient temperature and uses readily available dihydropyridines as precursors of carbamoyl radicals. The method's mild reaction conditions make
simple condensation first converts ketones into prearomatic intermediates that then act as activated radical sources for cross-coupling with aryl halides. Our strategy enables the direct benzylation/benzoylation of (hetero)arenes under mild reaction conditions with high functional group tolerance.