The NHC-catalyzed asymmetric [3+2] cyclization of benzoyl cyanides to homoenolate generated from enals was reported. This methodology leads to the efficient construction of a series of chiral cyclic compounds bearing vicinal quaternary stereocenters under mild reaction conditions. Additionally, the representative large-scale and derivatization reactions of the chiral cyclic products reveal the potential synthetic utility of this protocol.
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http://dx.doi.org/10.1039/d2cc04025e | DOI Listing |
Polymers (Basel)
January 2025
Mitsubishi Gas Chemical Company, Inc., Tokyo 100-8324, Japan.
Transparent X-ray shielding polymer films were developed by bulk photo copolymerization of in situ prepared bismuth carboxylate prepolymers with polymerizable exomethylene moieties and ,-dimethylacrylamide (DMAA). The bismuth-containing prepolymers were prepared via the polycondensation of BiPh, 2-octenylsuccinic acid (OSA), and itaconic acid (IA) bearing an exomethylene group for polymerization. OSA was a chain extender by intermolecular condensation and a stopper by intramolecular cyclization to inhibit cross-linkage.
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January 2025
Department of Chemistry, Acadia University, Wolfville, NS B4P 2R6, Canada.
A concise, transition metal-free four-step synthetic pathway has been developed for the synthesis of tetracyclic heterosteroidal compounds, 14-aza-12-oxasteroids, starting from readily available 2-naphthol analogues. After conversion of 2-naphthols to 2-naphthylamines by the Bucherer reaction, subsequent selective C-acetylation was achieved via the Sugasawa reaction and reduction of the acetyl group using borohydride, which resulted into the corresponding amino-alcohols. The naphthalene-based amino-alcohols underwent double dehydrations and double intramolecular cyclization with oxo-acids leading to one-pot formation of a C-N bond, a C-O bond and an amide bond in tandem, to generate two additional rings completing the steroidal framework.
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January 2025
Institute of Chemistry and Chemical Technology, Faculty of Natural Sciences and Technology, Riga Technical University, P. Valdena Str. 3, LV-1048 Riga, Latvia.
A metal-free two-step synthetic approach for obtaining indole derivatives from aryl triazole fragment-containing compounds has been developed. In the first step, the Dimroth equilibrium, followed by nitrogen extrusion, Wolff rearrangement, and amine nucleophile addition, leads to the formation of -aryl ethene-1,1-diamines. In the second step, the latter intermediates are cyclized into the target 1-indoles in the presence of iodine.
View Article and Find Full Text PDFOrg Lett
January 2025
Engineering Research Center of Ministry of Education for Fine Chemicals, Shanxi University, Taiyuan 030006, P. R. of China.
Herein a novel and robust methodology to spiroimidazolidinones has been developed under a mild reaction. The reaction of (Z)-2-azido-3-phenylacrylic acids , aldehydes , amines , isocyanides , and isocyanides produced regioselectively spiroimidazolidinones in 71-88% yields via a sequential Ugi 4CR/Pd(0) catalyzed azide-isocyanide coupling/cyclization/rearrangement/hydroxylation reaction. Furthermore, the easily accessible starting materials, high bond-forming efficiency, and broad substituent tolerance make this strategy useful in synthetic and medicinal chemistry.
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January 2025
Guangzhou Municipal and Guangdong Provincial Key Laboratory of Molecular Target & Clinical Pharmacology, School of Pharmaceutical Sciences, Guangzhou Medical University, Guangzhou, Guangdong 511436, China.
Presented herein is a nickel-catalyzed chemo- and regioselective three-component tandem carboamination and cyclization of terminal alkynes with organoboronic acids and anthranils for facile and modular access to 2,3-substituted quinolines. In this process, anthranil has dual roles: serving as an electrophilic aminating reagent and a redox buffer to suppress the generation of an off-cycle Ni(0) complex. Moreover, the anionic acetylacetonate (acac) ligand was found to be vital to ensure a productive Ni(I)-Ni(III)-Ni(I) catalytic cycle.
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