A nickel(0) catalyst effectively mediates the cyclization of N-benzoyl aminals in the presence of a stoichiometric Lewis acid. This method enables preparation of a variety of isoindolinones with substitution on the benzoyl fragment and C-3 carbon. This reaction likely proceeds via an α-amidoalkylnickel(II) intermediate, which then may cyclize via either an electrophilic aromatic substitution or an insertion pathway.
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http://dx.doi.org/10.1021/ol201248c | DOI Listing |
J Am Chem Soc
January 2025
Department of Chemistry, Queen's University, Kingston, ON K7L 3N6, Canada.
Tambjamines are complex bipyrrole-containing natural products that possess promising bioactive properties. Although is known to produce both cyclic tambjamine MYP1 and the linear precursor (YP1), the biosynthetic machinery used to catalyze the site-selective oxidative carbocyclization at the unactivated 1° carbon of YP1 has remained unclear. Here, we demonstrate that a three-component Rieske system consisting of an oxygenase (TamC) and two redox partner proteins is responsible for this unprecedented activity on YP1 and potentially, a non-native substrate (BE-18591).
View Article and Find Full Text PDFPlant Physiol Biochem
January 2025
Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250012, China. Electronic address:
The major phytochemicals in the roots of Cudrania tricuspidata are prenylated xanthones, exhibiting significant structural diversity and bioactive properties, such as anti-inflammatory, antioxidative, and antitumor effects. The biosynthetic pathways of these compounds have not yet been resolved, limiting their production through synthetic biology. In this study, benzoyl-coenzyme A (CoA) ligase (BZL), benzophenone synthase (BPS), and benzophenone 3'-hydroxylase (B3'H) transcripts involved in the biosynthesis of xanthone were cloned and characterized from C.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Molecular Synthesis Center, Key Laboratory of Marine Drugs of Ministry of Education, Shandong Key Laboratory of Glycoscience and Glycotherapeutics, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China.
2-Deoxy-β-glycosides are essential components of natural products and pharmaceuticals; however, the corresponding 2-deoxy-β-glycosidic bonds are challenging to chemically construct. Herein, we describe an efficient catalytic protocol for synthesizing 2-deoxy-β-glycosides via either IPrAuNTf-catalyzed activation of a unique 1,2--positioned C2--propargyl xanthate (OSPX) leaving group or (PhO)PAuNTf-catalyzed activation of a 1,2--C2--alkynylbenzoate (OABz) substituent of the corresponding thioglycosides. These activation processes trigger 1,2-alkyl/arylthio-migration glycosylation, enabling the synthesis of structurally diverse 2-deoxy-β-glycosides under mild reaction conditions.
View Article and Find Full Text PDFJ Org Chem
January 2025
School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu 241000, PR China.
-Iodosuccinimide-promoted cascade reactions of arylidene isoxazolones with amidines in -xylene were accomplished, affording 5-acylimidazoles in good to excellent yields. Interestingly, when the reactions were performed by employing acetonitrile as the solvent, 4-acylimidazoles were efficiently obtained. Mechanistic studies indicate that the formation of imidazolyl and acyl moieties may undergo a spiroannulation-ring opening aromatization-hydrolysis cascade reaction sequence.
View Article and Find Full Text PDFOrg Lett
January 2025
School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China.
The catalytic asymmetric multicomponent acylation/rearrangement/cyclization of alkenylfurans with acyl oxime esters/arylamines or acyl oxime esters/arylamines/hydroxylamine has been developed. This method employs synergistic photoredox/Brønsted acid catalysis, enabling the efficient and versatile synthesis of multifunctionalized [3.2.
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