26906-01-4Relevant academic research and scientific papers
Tandem Olefin Isomerization/Cyclization Catalyzed by Complex Nickel Hydride and Br?nsted Acid
Kathe, Prasad M.,Caciuleanu, Alexandru,Berkefeld, Andreas,Fleischer, Ivana
, p. 15183 - 15196 (2020/11/30)
We disclose a nickel/Br?nsted acid-catalyzed tandem process consisting of double bond isomerization of allyl ethers and amines and subsequent intramolecular reaction with nucleophiles. The process is accomplished by [(Me3P)4NiH]N(SO2CF3)2 in the presence of triflic acid. The methodology provides rapid access to tetrahydropyran-fused indoles and other oxacyclic scaffolds under very low catalyst loadings.
The winding road of the uvaretin class of natural products: From total synthesis to bioactive agent discovery
Dallman, Johnathan,Lansakara, Ashabha,Nguyen, Thi,Weeramange, Chamitha,Hulangamuwa, Wasundara,Rafferty, Ryan J.
, p. 1420 - 1431 (2019/08/21)
Herein, we disclose the development of a synthetic route to gain access to the uvaretin class of chalcone natural products. In this, the construction of a small library was achieved, and the collection was evaluated for cytotoxicity and other biological properties. Uvaretin (1) was accessed via a seven-step route in an overall yield of 15.1%. Within this route, the unsaturated enone variant of uvaretin (2), also a natural product, was accessed in a 16.7% yield over six steps. This route provides a nearly three-fold increase in yields of 1 and 2 in comparison to the previous synthetic route accessing them in 5.8% and 3.0% overall yields, respectively. Evaluation of 1 and 2 revealed IC50 values between 2.0 and 5.1 μM in the cancerous cell lines HeLa, U937, A549, and MIA PaCa-2. Screening of the whole chalcone library set led to the discovery of over 30 compounds, within six cancerous cell lines, possessing single digit μM IC50 activity as sole agents. Furthermore, multiple library members were found to possess promising potentiating properties with known chemotherapeutic agents.
Tetrahydrobenzochromene Synthesis Enabled by a Deconjugative Alkylation/Tsuji-Saegusa-Ito Oxidation on Knoevenagel Adducts
Navaratne, Primali V.,Grenning, Alexander J.
supporting information, p. 4566 - 4570 (2018/08/09)
A modular and practical route to versatile cyano-1,3-dienes by a sequence involving deconjugative alkylation and "Tsuji-Saegusa-Ito oxidation" is reported. In this letter, the versatility of the products is also explored, including a route to benzochromene scaffolds common to many natural products.
Novel Hypoxia-Inducible Factor 1α (HIF-1α) Inhibitors for Angiogenesis-Related Ocular Diseases: Discovery of a Novel Scaffold via Ring-Truncation Strategy
An, Hongchan,Lee, Seungbeom,Lee, Jung Min,Jo, Dong Hyun,Kim, Joohwan,Jeong, Yoo-Seong,Heo, Mi Jeong,Cho, Chang Sik,Choi, Hoon,Seo, Ji Hae,Hwang, Seyeon,Lim, Jihye,Kim, Taewoo,Jun, Hyoung Oh,Sim, Jaehoon,Lim, Changjin,Hur, Joonseong,Ahn, Jungmin,Kim, Hyun Su,Seo, Seung-Yong,Na, Younghwa,Kim, Seok-Ho,Lee, Jeewoo,Lee, Jeeyeon,Chung, Suk-Jae,Kim, Young-Myeong,Kim, Kyu-Won,Kim, Sang Geon,Kim, Jeong Hun,Suh, Young-Ger
, p. 9266 - 9286 (2018/10/24)
Ocular diseases featuring pathologic neovascularization are the leading cause of blindness, and anti-VEGF agents have been conventionally used to treat these diseases. Recently, regulating factors upstream of VEGF, such as HIF-1α, have emerged as a desirable therapeutic approach because the use of anti-VEGF agents is currently being reconsidered due to the VEGF action as a trophic factor. Here, we report a novel scaffold discovered through the complete structure-activity relationship of ring-truncated deguelin analogs in HIF-1α inhibition. Interestingly, analog 6i possessing a 2-fluorobenzene moiety instead of a dimethoxybenzene moiety exhibited excellent HIF-1α inhibitory activity, with an IC50 value of 100 nM. In particular, the further ring-truncated analog 34f, which showed enhanced HIF-1α inhibitory activity compared to analog 2 previously reported by us, inhibited in vitro angiogenesis and effectively suppressed hypoxia-mediated retinal neovascularization. Importantly, the heteroatom-substituted benzene ring as a key structural feature of analog 34f was identified as a novel scaffold for HIF-1α inhibitors that can be used in lieu of a chromene ring.
Modular Synthesis of Diverse Natural Product-Like Macrocycles: Discovery of Hits with Antimycobacterial Activity
Dow, Mark,Marchetti, Francesco,Abrahams, Katherine A.,Vaz, Luis,Besra, Gurdyal S.,Warriner, Stuart,Nelson, Adam
supporting information, p. 7207 - 7211 (2017/05/31)
A modular synthetic approach was developed in which variation of the triplets of building blocks used enabled systematic variation of the macrocyclic scaffolds prepared. The approach was demonstrated in the synthesis of 17 diverse natural product-like macrocyclic scaffolds of varied (12–20-membered) ring size. The biological relevance of the chemical space explored was demonstrated through the discovery of a series of macrocycles with significant antimycobacterial activity.
Ring-closing metathesis reaction-based synthesis of new classes of polyether macrocyclic systems
Naveen,Babu, Srinivasarao Arulananda
, p. 7758 - 7781 (2015/09/08)
Ring closing metathesis (RCM) reactions of suitable substrates having terminal olefins, which are assembled from various linkers and hydroxy benzaldehydes and syntheses of a wide range of 16-30 membered, new crown ether-type polyether, aza-polyether, bis aza-polyether macrocycles and dilactone moiety embedded polyether macrocycles (macrolides) are reported. After the ring-closure reaction, installation of different functional groups and functional group modification on the periphery of the synthesized polyether/crown ether macrocycles obtained in the RCM reactions are accomplished using the epoxidation, oxidation and catalytic hydrogenation-based synthetic transformations. Along this line, the syntheses of a variety of polyether macrocycles possessing epoxide or α-hydroxy ketone or 1,2-diol functionalities at the periphery have been shown. Furthermore, the synthesized α-hydroxy ketone functionality installed polyether macrocycles were subjected to the allylation and Reformatsky type reactions to obtain homoallyl alcohol moiety-based and lactone ring-appended polyether macrocycles.
INHIBITORS OF HUMAN IMMUNODEFICIENCY VIRUS REPLICATION
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Page/Page column 100, (2014/10/18)
The disclosure generally relates to compounds of formula I, including compositions and methods for treating human immunodeficiency virus (HIV) infection. The disclosure provides novel inhibitors of HIV, pharmaceutical compositions containing such compounds, and methods for using these compounds in the treatment of HIV infection. Formule (I)
Mechanism of alcohol oxidation mediated by copper(II) and nitroxyl radicals
Ryland, Bradford L.,McCann, Scott D.,Brunold, Thomas C.,Stahl, Shannon S.
supporting information, p. 12166 - 12173 (2014/12/09)
2,2′-Bipyridine-ligated copper complexes, in combination with TEMPO (2,2,6,6-tetramethylpiperidine-N-oxyl), are highly effective catalysts for aerobic alcohol oxidation. Considerable uncertainty and debate exist over the mechanism of alcohol oxidation mediated by CuII and TEMPO. Here, we report experimental and density functional theory (DFT) computational studies that distinguish among numerous previously proposed mechanistic pathways. Oxidation of various classes of radical-probe substrates shows that long-lived radicals are not formed in the reaction. DFT computational studies support this conclusion. A bimolecular pathway involving hydrogen-atom-transfer from a CuII-alkoxide to a nitroxyl radical is higher in energy than hydrogen transfer from a CuII-alkoxide to a coordinated nitroxyl species. The data presented here reconcile a collection of diverse and seemingly contradictory experimental and computational data reported previously in the literature. The resulting Oppenauer-like reaction pathway further explains experimental trends in the relative reactivity of different classes of alcohols (benzylic versus aliphatic and primary versus secondary), as well as the different reactivity observed between TEMPO and bicyclic nitroxyls, such as ABNO (ABNO = 9-azabicyclo[3.3.1]nonane N-oxyl).
Intramolecular reactions of metal carbenoids with allylic ethers: Is a free ylide involved in every case?
Clark, J. Stephen,Hansen, K. Emelie
supporting information, p. 5454 - 5459 (2014/05/20)
Rhodium-, copper- and iridium-catalyzed reactions of the 13C-labelled diazo carbonyl substrates 18* and 19* were performed. Results obtained from copper- and iridium-catalyzed reactions of the 13C-labelled α-diazo β-keto ester 19* indicate that either or both of these reactions do not proceed via a free oxonium ylide but instead follow a competing non-ylide route that delivers apparent [2,3]-sigmatropic rearrangement products. In the case of the iridium-catalyzed reaction of α-diazo β-keto ester 19*, results obtained from crossover experiments indicate that the initially formed metal-bound ylide dissociates to give an iridium enolate and an allyl cation, which recombine to form the C-C bond. Differing distributions of 13C-labelled rearrangement products in the rhodium-, copper- and iridium-catalyzed reactions of a 13C-labelled α-diazo β-keto ester (see scheme, DCE=dichloroethane, acac=acetylacetonate, COD=1,5-cyclooctadiene) revealed that the copper- and iridium-mediated reactions do not proceed via a common free oxonium ylide intermediate.
MACROCYCLIC PURINES FOR THE TREATMENT OF VIRAL INFECTIONS
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Page/Page column 84; 85; 135, (2014/02/15)
This invention relates macrocyclic purine derivatives having formula (I), processes for their preparation, pharmaceutical compositions, and their use in treating viral infections.
