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The asymmetric cycloaddition reaction of -quinone monoimides is a significant research focus for constructing benzofused heterocycles. However, due to steric effects, achieving efficient cycloaddition at highly sterically hindered site is challenging but practically valuable. Herein, we develop an asymmetric [3 + 2] cycloaddition reaction of -quinone monoimides with 1-vinylnaphthalen-2-ols and 3-vinylindoles via steric hindrance-overcoming strategy. Binaphthalene-based chiral phosphoric acid catalyzes the asymmetric cycloaddition reaction to synthesize highly functionalized 2,3-dihydrobenzofurans in generally good yields with good to excellent stereoselectivities.
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http://dx.doi.org/10.1021/acs.joc.5c00764 | DOI Listing |
J Org Chem
September 2025
Institute of Integrated Science and Technology, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521, Japan.
An efficient method for the enantio- and diastereoselective synthesis of tricyclic γ-butyrolactones bearing three quaternary stereocenters has been developed through transformations of achiral alkenoic acid substrates. The target optically active tricyclic lactones were obtained as single diastereomers with good enantioselectivities through a sequence of catalytic asymmetric bromolactonization, azidation, and subsequent 1,3-dipolar cycloaddition. The origin of the complete diastereoselectivity observed in the formation of the tricyclic γ-butyrolactone products was elucidated in this study.
View Article and Find Full Text PDFOrg Lett
September 2025
School of Pharmaceutical Sciences & Institute of Materia Medica, Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250117, Shandong, P. R. China.
In this work, we developed nucleophilic 2-aminoallyl cations guided by DFT calculations. Computational insights enabled a comprehensive analysis of factors governing N-nucleophilicity and an accurate prediction of cycloaddition reactivity with electron-deficient alkenes. Notably, this study represents the first asymmetric [3 + 2] cycloaddition of amino-allyl cations with exocyclic double bonds, enabling the efficient synthesis of -pyrrolidines with excellent diastereoselectivities and enantioselectivities.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
September 2025
Department of Chemistry, Fudan University, 220 Handan Rd, Shanghai, 200433, China.
The Diels-Alder/cheletropic retro-[4+1] cycloadditions of thiophene S,S-dioxides are a prominent method for synthesizing unsaturated six-membered carbocycles. However, to the best of our knowledge, catalytic asymmetric variations of these reactions have not yet been achieved. Herein, we report Fe(III)-bis(oxazoline) complex-catalyzed inverse-electron-demand [4+2] cycloaddition/cheletropic retro-[4+1] extrusion of SO reactions between thiophene S,S-dioxides and 3-substituted indoles.
View Article and Find Full Text PDFThe tetrodecamycins are tetracyclic natural products that exhibit potent antimicrobial activity against a multitude of drug-resistant pathogens. These compounds are structurally distinguished by the presence of a tetronate ring and -decalin with six contiguous asymmetric centres united by a seven-membered oxygen heterocycle. Herein we describe the first total synthesis of the antibiotic (-)-13-deoxytetrodecamycin.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
August 2025
Department of Chemistry, Aarhus University, Aarhus C, 8000, Denmark.
The enantioselective [4 + 4] cycloaddition for the construction of cyclooctanoids is a challenging transformation in organic chemistry. Herein, we present the first organocatalytic enantioselective [4 + 4] cycloaddition of furan ortho-quinodimethanes, activated by dearomatization of the heteroaromatic compound, which thereby allows for the cycloaddition with dienes. The [4 + 4] cycloaddition is catalyzed by a quinine-derived primary amine in combination with a chiral phosphoric acid and a carboxylic acid affording cyclooctanoids isolated as a single diastereoisomer in good yields and with up to 94% ee.
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