Chiral eight-membered heterocycles comprise a diverse array of natural products and bioactive compounds, yet accessing them poses significant challenges. Here we report a gold-catalyzed stereoselective (4 + 4) cycloaddition as a reliable and divergent strategy, enabling readily accessible precursors (anthranils and -quinone methides) to be intercepted by generated gold-furyl 1,4-dipoles, delivering previously inaccessible chiral furan/pyrrole-containing eight-membered heterocycles with good results (56 examples, all >20 : 1 dr, up to 99% ee). Moreover, we achieve a remarkably efficient kinetic resolution (KR) process (s factor up to 747). The scale-up synthesis and diversified transformations of cycloadducts highlight the synthetic potential of this protocol. Computational calculations provide an in-depth understanding of the stereoselective cycloaddition process.
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http://dx.doi.org/10.1039/d4sc02763a | DOI Listing |
Org Lett
January 2025
Catalytic Hydrogenation Research Center, State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Key Laboratory of Green Pesticides and Cleaner Production Technology of Zhejiang Province, Zhejiang University of Technology, Hangzhou 310014, P. R. China.
This work describes a chiral bifunctional squaramide/DBU sequential catalytic strategy for the enantioselective synthesis of nonfused chiral eight-membered O-heterocycles through the asymmetric addition of ynones to β,γ-unsaturated α-ketoesters followed by the regio- and diastereoselective cyclization of the adduct intermediates. Mechanistic experiments revealed that an isomerization process should be involved in the ring formation step, and the origin of the high regioselectivity and diastereoselectivity has also been elucidated by the DFT calculations.
View Article and Find Full Text PDFMolecules
November 2024
Department of Chemistry, Faculty of Science, Sohag University, Sohag 82524, Egypt.
A series of new quinazolin-2,4-dione derivatives incorporating amide/eight-membered nitrogen-heterocycles -, in addition, acylthiourea/amide/dithiolan-4-one and/or phenylthiazolidin-4-one - and -. The starting compound was prepared by reaction of 4-(2,4-dioxo-1,4-dihydro-2-quinazolin-3-yl)-benzoyl chloride with ammonium thiocyanate and cyanoacetic acid hydrazide. The reaction of with strong electrophiles, namely, -aminophenol, -amino thiophenol, and/or -phenylene diamine, resulted in corresponding quinazolin-2,4-dione derivatives incorporating eight-membered nitrogen-heterocycles -.
View Article and Find Full Text PDFOrg Lett
December 2024
State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, China.
The fused eight-membered carbocycles (EMCs) play vital roles in the medicinal and biological investigations of many natural products and marketed drugs. The traditional synthesis of [6-8-6] benzo-fused derivatives involves multistep reactions and low yields, making the development of a one-step synthesis method a more challenging work. Here, we present a novel strategy for one-step construction of [6-8-6] benzo-fused scaffold from propargyl diazoacetates substituted with benzyl-nitrogen heterocyclic ring via Rh(ll)-catalyzed carbene/alkyne metathesis (CAM) and selective C-H bond insertion.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
November 2024
Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, 01062, Dresden, Germany.
Angew Chem Int Ed Engl
January 2025
Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Chemical Biology Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing, 401331, P. R. China.
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