145238-34-2Relevant academic research and scientific papers
Radical-Cation Cascade to Aryltetralin Cyclic Ether Lignans Under Visible-Light Photoredox Catalysis
Wang, Qian,Xiang, Jia-Chen,Zhu, Jieping
supporting information, p. 21195 - 21202 (2020/09/17)
The development of concise, sustainable, and cost-effective synthesis of aryltetralin lignans, bearing either a fused lactone or cyclic ether, is of significant medicinal importance. Reported is that in the presence of Fukuzumi's acridinium salt under blue LED irradiation, functionalized dicinnamyl ether derivatives are converted into aryltetralin cyclic ether lignans with concurrent generation of three stereocenters in good to high yields with up to 20:1 diastereoselectivity. Oxidation of an alkene to the radical cation is key to the success of this formal Diels–Alder reaction of electronically mismatched diene and dienophile. Applying this methodology, six natural products, aglacin B, aglacin C, sulabiroin A, sulabiroin B, gaultherin C, and isoshonanin, are synthesized in only two to three steps from readily available biomass-derived monolignols. A revised structure is proposed for gaultherin C.
Hypervalent iodine initiated intramolecular alkene dimerisation: A stereodivergent entry to cyclobutanes
Zhu, Yuxiang,Colomer, Ignacio,Donohoe, Timothy J.
, p. 10316 - 10319 (2019/09/03)
The emergence of new methods for the stereoselective synthesis of strained carbocycles is a challenging but worthwhile endeavour. Cyclobutanes, in particular, have attracted the attention of both medicinal chemists and material scientists for their unique properties. Herein, we present a new method that allows access to highly functionalized cyclobutanes with complementary all-trans and trans-cis-trans relative stereochemistry, that could not be accessed before. This approach consists of an intramolecular dimerisation of non-conjugated dienes using an oxidative single electron transfer (SET) process, and is initiated by catalytic amounts of hypervalent iodine reagents. The potential uses of these cyclobutanes is demonstrated with selective functionalization, including the formation of diols and carboxylic acids.
Endoperoxide synthesis by photocatalytic aerobic [2 + 2 + 2] cycloadditions
Parrish, Jonathan D.,Ischay, Michael A.,Lu, Zhan,Guo, Song,Peters, Noel R.,Yoon, Tehshik P.
scheme or table, p. 1640 - 1643 (2012/05/04)
Structurally novel endoperoxides can be sythesized by the photocatalytic cyclotrimerization of bis(styrene) substrates with molecular oxygen. The optimal catalyst for this process is Ru(bpz)32+, which is a markedly more efficient catalyst for these photooxygention reactions than conventional organic photosensitizers. The 1,2-dioxolane products are amenable to synthetic manipulation and can be easily processed to 1,4-diols and γ-hydroxyketones. An initial screen of the biological activity of these compounds reveals promising inhibition of cancer cell growth.
Cycloadditions by oxidative visible light photocatalysis
Ischay, Michael A.,Lu, Zhan,Yoon, Tehshik P.
supporting information; experimental part, p. 8572 - 8574 (2010/08/06)
Photochemical reactions are remarkable for their ability to easily assemble cyclobutanes and other strained ring systems that are difficult to construct using other conventional synthetic methods. We have previously shown that Ru(bpy)32+ is an efficient photocatalyst that promotes the [2+2] cycloadditions of electron-deficient olefins with visible light. Here, we show that Ru(bpy)32+ is also an effective photocatalyst for the [2+2] cycloaddition of electron-rich olefins. This transformation is enabled by the versatile photoelectrochemical properties of Ru(bpy) 32+, which enables either one-electron reduction or one-electron oxidation of interesting organic substrates under appropriate conditions.
