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Dienyl diketones containing tethered acetates selectively undergo two different 1,6-conjugate addition-initiated cyclization cascades. One is a 1,6-conjugate addition/cyclization sequence with incorporation of the nucleophile, and the other is catalyzed by DABCO and is thought to proceed via a cyclic acetoxonium intermediate. The reaction behavior of substrates lacking the tethered acetate was also studied. The scope of both types of cyclization cascades, the role of the amine additive, and the factors controlling reactivity and selectivity in the two different reaction pathways is discussed.
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http://dx.doi.org/10.1021/ja308451y | DOI Listing |
J Org Chem
September 2025
College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Nanyang, Henan 473061, China.
A visible-light-induced cascade cyclization of isocyanobiaryls with hydrosilanes has been developed for the synthesis of 6-silylated phenanthridines. Readily available hydrosilanes were employed as silyl radical precursors under room-temperature conditions. The merits of the transformation include operational simplicity, mild conditions, high atom economy, and good functional group compatibility.
View Article and Find Full Text PDFRSC Adv
August 2025
Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences Tehran Iran
Indolo/benzimidazo-isoquinoline scaffolds are frequently found in many natural products, pharmaceuticals, and organic materials. Owing to their prominent properties, in recent years, numerous studies have been performed on the synthesis of indolo/benzimidazo-isoquinoline derivatives photo-, and electro-promoted functionalization/cyclization reactions of -acryloyl 2-aryl indoles/benzimidazoles. In this review, we describe these fascinating transformations and discuss their mechanistic insights.
View Article and Find Full Text PDFJ Org Chem
September 2025
Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, P. R. of China.
A Mg(OTf)-catalyzed asymmetric Michael addition/cyclization cascade reaction between 3-isothiocyanato oxindoles and 2-arylidene-1,3-indanediones has been developed. This transformation provides an efficient and concise approach to biologically important bispiro[indanedione-oxindole-pyrrolidinyl]s under mild conditions in good to excellent yields (70-99% yields) with moderate to good stereoselectivities (up to 99% and >95:5 d.r.
View Article and Find Full Text PDFOrg Lett
September 2025
Precise Synthesis and Function Development Key Laboratory of Sichuan Province, China West Normal University, Nanchong, 637002, China.
A novel strategy for accessing unprecedented silyl/fluoroalkyl-embedded tetracyclic pyrrolizidinediones has been developed through the visible-light-induced cascade cyclization of 3-methyleneisoindolin-1-ones using hydrosilanes or fluoroalkylsulfinate salts as radical sources under redox-neutral conditions. This protocol features mild reaction conditions, operational simplicity, and excellent compatibility with various functional groups. A number of silyl/fluoromethyl-decorated tetracyclic pyrrolizidinedione frameworks were efficiently created.
View Article and Find Full Text PDFJ Org Chem
September 2025
Yunnan Key Laboratory of Modern Separation Analysis and Substance Transformation, College of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming, Yunnan Province 650500, P. R. China.
Photoinduced trifluoroethyl and acyl radical procedures for the efficient and simple preparation of iodotrifluoroethylated and acylated pyrrolidine-2-ones from -tethered 1,6-enynes with 1,1,1-trifluoro-2-iodoethane and acyl oxime esters are reported. The photoinduced iodotrifluoroethylation is performed via the energy transfer (EnT) process of the fluorescein sodium-mediated atom-transfer radical addition (ATRA) strategy under visible-light irradiation. The acylation is carried out with 4CzIPN as an organophotocatalyst at room temperature under metal- and oxidant-free conditions.
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