[reaction: see text] Thermal decomposition of phenyliodonium ylide of 2-hydroxy-1,4-naphthoquinone (lawsone) in the presence of indole derivatives affords 3-acylated indoles existing in their enol forms, through a ring contraction and alpha,alpha'-dioxoketene formation reaction. The same reactants afford 3-(3-indolyl)-2-hydroxy-1,4-naphthoquinones in a copper-catalyzed reaction. Enamines, among other C-nucleophiles tested, give analogous results.
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http://dx.doi.org/10.1021/jo051151t | DOI Listing |
J Org Chem
January 2021
School of Natural Sciences - Chemistry, University of Tasmania, Hobart, Tasmania 7001, Australia.
We have identified and extensively investigated the photochemical activation and reaction of a hydroxyquinone-derived phenyliodonium ylide in the presence of visible light using experiment and theory. These studies revealed that in its photoexcited state this iodonium is capable of facilitating a range of single-electron transfer (SET) processes, including hydrogen atom transfer (HAT), a Povarov-type reaction, and atom-transfer radical addition chemistry. Where possible, we have employed density functional theory (DFT) to develop a more complete understanding of these photoinduced synthetic transformations.
View Article and Find Full Text PDFChem Commun (Camb)
October 2020
Henan Key Laboratory of Organic Functional Molecules and Drug Innovation, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China.
A highly enantioselective cyclopropanation to synthesize pyrimidine-substituted diester D-A cyclopropanes is reported. Various N1-vinylpyrimidines react well with phenyliodonium ylides, delivering chiral cyclopropanes in up to 97% yield with up to 99% ee. Through simple [3+2] annulation with benzaldehyde or ethyl glyoxylate, different chiral pyrimidine nucleoside analogues with a sugar ring could be obtained.
View Article and Find Full Text PDFOrg Lett
April 2019
Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China) and Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province , Hunan Normal University, Changsha 410081 , China.
Silver-catalyzed tandem cyclization-elimination reactions of conjugated ene-yne-ketones in PhI(OAc)/triethylamine system lead to the formation of 2-alkenylfurans. 2-Furylsilver carbene and phenyliodonium ylide are proposed as the key intermediates in these transformations.
View Article and Find Full Text PDFChem Commun (Camb)
October 2018
Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, People's Republic of China.
Chiral Lewis acid-promoted enantioselective α-alkylation of β-ketoamides with phenyliodonium ylide was developed. In the presence of a chiral N,N'-dioxide/Ni(ii) complex, the corresponding 1,4-dicarbonyl compounds were obtained with good results (up to 91% yield and 97% ee). Control experiments and EPR studies supported a radical process.
View Article and Find Full Text PDFChem Sci
April 2016
Key Laboratory of Green Chemistry & Technology , Ministry of Education , College of Chemistry , Sichuan University, Chengdu 610064 , China . Email: ; Email: ; ; Tel: +86 28 85418249.
A chiral Lewis acid-promoted enantioselective cyclopropanation using phenyliodonium ylide as the carbene precursor was developed. A variety of spirocyclopropane-oxindoles with contiguous tertiary and all carbon quaternary centers were obtained in excellent outcomes (up to 99% yield, >19 : 1 d.r.
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