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Journal of Organic Chemistry

Maria Annunziata M Capozzi, Angela Punzi, Francesco Babudri, Roberta Musio, Gianluca M Farinola
The synthesis of two new dye families of croconic acid derivatives, semicroconaine and non-symmetric croconaine dyes, is reported for the first time. These compounds show strong absorption in the UV-visible and NIR, respectively. Semicrocon-aine dyes were obtained by a scalable and efficient condensation of croconic acid with aromatic heterocyclic methylene-active compounds. The subsequent reaction of the semicroconaine dyes with aromatic heterocyclic compounds affords non-symmetric croconaines. The structure and electronic properties of the synthesized compounds have been investigated by preliminary theoretical calculations at DFT level of approximation...
November 13, 2018: Journal of Organic Chemistry
Hong Lu, Chang-Yin Tan, Huan-Xin Zhang, Jia-Lu Zhang, Jin-Yu Liu, Hong-Yu Li, Peng-Fei Xu
An N-heterocyclic carbene-catalyzed and β-ketothioamide participated asymmetric [3+3] spiroannulataion was successfully developed. β-Ketothioamides exhibit a superior ability to enable the previously challenging lactamization reaction, and the corresponding spiro-piperidinones derivatives containing two consecutive stereogenic centers were synthesized in good to high yields with high stereoselectivities, whose structure can be converted to corresponding imide and δ-lactam derivatives smoothly.
November 13, 2018: Journal of Organic Chemistry
Kubandiran Kolanji, Lars Postulka, Bernd Wolf, Michael Lang, Dieter Schollmeyer, Martin Baumgarten
Four weakly antiferromagnetic interacting biradicals of benzo[1,2-b:4,5-b']dithiophene (BDT), and BDT extended with two thiophenes (BDTTh2) linked with nitronyl- and imino-nitroxides (NN and IN) as BDT-NN, BDT-IN, BDTTh2-NN and BDTTh2-IN were designed synthesized and characterized. Short inter-molecular π-π distances were found (3.42 Å) for BDT-NN whereas larger ones for BDT-IN (3.54 Å) and BDTTh2-NN (3.67 Å), respectively. Intra-molecular magnetic interaction (Jintra,exp/kB) of BDT-NN (-26 K) is much larger than for BDT-IN (-5...
November 13, 2018: Journal of Organic Chemistry
Siran Qian, Zengyang Xie, Jiaming Liu, Mingshuang Li, Shan Wang, Naili Luo, Cunde Wang
A DBU-promoted cascade annulation of nitroarylcyclopropane-1,1-dicarbonitriles and 3-aryl-2-cyanoacrylates for the synthesis of highly functionalized cyclopenta[ b]furan derivatives is described. High stereoselectivity, fused cyclopentane and furan can be established in a single reaction, highlighting the high efficiency and step-economy of this protocol. This reaction offers a novel and straightforward protocol to the synthesis of cyclopenta[ b]furans featuring the [3 + 2] cycloadditions of nitroarylcyclopropane-1,1-dicarbonitriles with 3-aryl-2-cyanoacrylates...
November 13, 2018: Journal of Organic Chemistry
Pingshun Zhang, Wanzhi Chen, Miaochang Liu, Huayue Wu
Three component reactions of olefins, amines, and sulfur were studied. Thioamidation of styrenes is base-controlled, and 2-phenylethanethioamides and benzothioamides were obtained selectively in the presence of two different bases. This protocol offers a simple and efficient procedure for the synthesis of thioamides.
November 13, 2018: Journal of Organic Chemistry
Soumyaditya Mula, Nicolas Leclerc, Patrick Lévêque, Pascal Retailleau, Gilles Ulrich
New synthetic strategies were developed for the synthesis of indolo-pyridine boron difluoride (IPBD) dyes and antiladder-type π-conjugated dyes based on the pyridine/pyrazine-indolocarbazole (ICZ) structures. The photophysical and electrochemical properties of the dyes were measured in solution, solid state, and thin films and rationalized by theoretical calculations. Interestingly, these properties of the dyes can be tuned in a wide range using the developed chemical route. For example, the absorption range and fluorescence color of the dyes in solution and solid state and the HOMO-LUMO energy gaps were tuned by structure modulations...
November 13, 2018: Journal of Organic Chemistry
Yumiao Ma, Zongchang Han
We explored the mechanism of Markovnikov-selective hydrosilylation of phenylacetylene catalyzed by N-N-N Pincer-cobalt complex with density functional theory (DFT) calculations. In contrast to the previously proposed Co(I) mechanism, computational results suggests a Co(0) pathway, which is further supported by experimental studies. At the same time, our study reveals the unexpected complexity in terms of the origin of regioselectivity. Firstly, different orientations between phenyl group in substrate and ligand plane lead to two possible transition states responsible for branched product...
November 12, 2018: Journal of Organic Chemistry
Joseph N Capilato, Desta Doro Bume, Wei Hao Lee, Louis E S Hoffenberg, Rayyan Trebonias Jokhai, Thomas Lectka
The halofunctionalization of alkene substrates remains an essential tool for synthetic chemists. Herein, we report regioselective ammoniofluorination of unactivated alkenes through photochemical means. A one-pot transformation of the ammonium fluoride products into pharmaceutically relevant β-fluoropiperazines is highlighted. Furthermore, a substrate-guided reactivity switch is observed: certain alkenes are shown to react with the same fluorinating reagent to instead give the less-substituted fluoride. We hope that the ammoniofluorination reaction will be of utility in the area of medicinal chemistry, where nitrogen and fluorine are among the most important heteroatoms...
November 12, 2018: Journal of Organic Chemistry
Richard J Fox, Nicolas L Cuniere, Lopa Bakrania, Carolyn Wei, Neil A Strotman, Michael Hay, Dayne Fanfair, Christopher Regens, Gregory L Beutner, Michael Lawler, Paul Lobben, Maxime C Soumeillant, Benjamin Cohen, Keming Zhu, Dimitri Skliar, Thorsten Rosner, Chester E Markwalter, Yi Hsiao, Kristy Tran, Martin D Eastgate
The development of an improved short and efficient commercial synthesis of the JAK2 inhibitor, a complex pyrrolopyridine, BMS-911543, is described. During the discovery and development of this synthesis, a Pd-catalyzed C-H functionalization was invented which enabled the rapid union of the key pyrrole and imidazole fragments. The synthesis of this complex, nitrogen-rich heterocycle was accomplished in only six steps (longest linear sequence) from readily available materials.
November 12, 2018: Journal of Organic Chemistry
Jonathan S Ward, Roberto S Nobuyasu, Mark A Fox, Andrei S Batsanov, Jose Santos, Fernando B Dias, Martin R Bryce
The synthesis of 1-methylphenoxazine via CO2 -directed lithiation chemistry is reported. This electron donor was coupled with 2,8-dibromodibenzothiophene- S, S-dioxide with Buchwald-Hartwig chemistry to give a new donor-acceptor-donor charge-transfer fluorescent molecule 1b. X-ray crystal structures and calculations show that the phenoxazinyl groups are coplanar and equatorial (eq) to the acceptor plane in nonmethylated 1a but are pyramidal and axial (ax) in 1b. The bond rotation energy barriers between donor and acceptor groups for 1a and 1b are only 0...
November 12, 2018: Journal of Organic Chemistry
Jason M Stevens, Ana Cristina Parra-Rivera, Darryl D Dixon, Gregory L Beutner, Albert J DelMonte, Doug E Frantz, Jacob M Janey, James Paulson, Micheal R Talley
The identification of Yb(OTf)3 through a multivariable high-throughput experimentation strategy has enabled a unified protocol for the direct conversion of enantioenriched N-acyl oxazolidinones to the corresponding chiral esters, amides and carboxylic acids. This straightforward and catalytic method has shown remarkable chemoselectivity for substitution at the acyclic N-acyl carbonyl for a diverse array of N-acyl oxazolidinone substrates. The ionic radius of the Lewis acid catalyst was demonstrated as a key driver of catalyst performance that lead to the identification of a robust and scalable esterification of a pharmaceutical intermediate using catalytic Y(OTf)3...
November 9, 2018: Journal of Organic Chemistry
Brandon A Wright, Michael J Ardolino
α-Arylations of cyclopropyl and related nitriles provide access to important synthetic intermediates and pharmacophores for biologically active molecules. However, robust methods for coupling of sterically encumbered partners have remained elusive. Through optimization using high-throughput experimentation (HTE), the NiXantphos ligand was found to be effective in the coupling of sterically hindered β-substituted cyclopropyl nitriles with a number of aryl groups and heterocycles, including those containing acidic N-H and O-H bonds...
November 9, 2018: Journal of Organic Chemistry
Pierre Thilmany, Phidéline Gérard, Agathe Vanoost, Christopher Deldaele, Laurent Petit, Gwilherm Evano
A set of two efficient and broadly applicable procedures for the N-arylation of hydantoins at the two nitrogen atoms is reported. The first one relies on the use of stoichiometric amounts of copper(I) oxide under ligandless and base-free conditions and enables a clean and regioselective arylation at the N3 nitrogen atom while the second one is based on the use of catalyt-ic amounts of copper(I) iodide and trans-N,N'-dimethylcyclohexane-1,2-diamine and promotes arylation at the N1 nitrogen atom. Importantly, the combination of these two procedures affords a straightforward and general entry to diarylated hydantoins...
November 9, 2018: Journal of Organic Chemistry
Paulina Plata, Urszula Klimczak, Bartosz K Zambroń
The application of the N-methylimidazole (N-MI) ligand in the Pd(0)/InI promoted allylations of aldehydes with β-lactam derived organoindiums enables the reaction of azetidin-2-ones with diversely substituted allyl moieties, inert under previously reported conditions. As a result, allylations and crotylations of a variety of aromatic and aliphatic aldehydes with previously unavailable chiral epsilon-amido-allylindiums bearing α-, β- or γ-substituted allyl fragments were developed. The reactions occur under thermodynamic control with highly efficient remote 1,5- or 1,4,5-stereocontrol to afford a diversity of (3Z)-2,5-anti-2,6-syn- or (3Z)-2,5-syn-2,6-anti-substituted enediols, aminoalcohols, and homoallylic alcohols in moderate to high yields and with excellent diastereoselectivity...
November 9, 2018: Journal of Organic Chemistry
Eric A Voight, Brian S Brown, Stephen Nathaniel Greszler, Geoff T Halvorsen, Gang Zhao, Albert W Kruger, John Hartung, Kirill A Lukin, Steven R Martinez, Eric G Moschetta, Michael T Tudesco, Nathan D Ide
ABBV-168 is a dihalogenated nucleotide under investigation for the treatment of hepatitis C virus (HCV). Three synthetic routes aimed at achieving the stereoselective installation of the C2' gem-Br,F substitution and subsequent Vorbruggen glycosylation were explored to prepare the penultimate nucleoside intermediate. Development culminated in a route to ABBV-168 featuring a de novo chromatography-free furanose synthesis, protecting group-directed Vorbruggen glycosylation, and highly selective phosphoramidation to furnish the API...
November 9, 2018: Journal of Organic Chemistry
Xuejian Xia, Qiongqiong Zhu, Jing Wang, Jie Chen, Weiguo Cao, Bo Zhu, Xiaoyu Wu
Asymmetric Mannich-type addition of 3,5-disubstituted-4-nitroisoxazles to isatin-derived N-Boc imines has been developed by employing 1 mol % of bifunctional amide phosphonium salt as a phase transfer catalyst. This methodology allows for the formation of 3-isoxazolylmethyl substituted 3-aminooxindoles bearing a tetrasubstituted stereogenic C3 in excellent yields and good to excellent enantioselectities. The utility of this methodology was shown by a relatively larger scale synthesis and application to the formal synthesis (+)-AG-041R...
November 9, 2018: Journal of Organic Chemistry
Weidong Sun, Ying Wang, Lishuang Ma, Lu Zheng, Weihai Fang, Xuebo Chen, Hua Jiang
Fullerene molecules have attracted considerable interest because of the unique curved aromatic π-conjugated systems. However, the complicated and costly technologies for purification of highly pure fullerenes hamper easy access to these attractive molecules and consequently limit most of fullerene applications. Here, we report the discovery of a carcerand-like cage acting as a stand-alone host for efficient separation and purification of C60 and C70 from fullerene soot. The cage, built through the self-assembly of metal coordination, is capable of quantitative encapsulating fullerenes C60 and C70...
November 9, 2018: Journal of Organic Chemistry
Jing Zhu, Wei-Chen Cui, Shaozhong Wang, Zhu-Jun Yao
A visible light-driven radical hydrosilylation of electron-neutral and -rich alkenes has been investigated on the basis of a newly developed catalytic reaction system composed of eosin Y, thiol, and base additives. A variety of linear and cyclic alkenes with different substitution patterns were found to undergo such metal-free hydrosilylation with tertiary and secondary hydrosilanes in a chemo-, regio-, and stereoselective manner. Comparison of the reactivity of diene compounds and late-stage hydrosilylation of steroid drugs were also explored...
November 9, 2018: Journal of Organic Chemistry
Konrad Koszinowski, David S Stephenson
Allylindium halides are valuable allylating reagents, which can even be applied in aqueous solutions. Previous 1 H NMR spectroscopic investigations suggested that these reagents are stable for several hours in D2 O, whereas ESI-mass spectrometric experiments in H2 O pointed to much shorter lifetimes. To resolve this seeming discrepancy, the present study systematically examines the solvolysis of allylindium iodide in H2 O, D2 O, and mixtures thereof by both analytical methods. Kinetic measurements find a large kinetic isotope effect (KIE = 12...
November 9, 2018: Journal of Organic Chemistry
Wei Huang, Yun Yao, Yan-Jun Xu, Chong-Dao Lu
A diastereoselective α-fluorination of N- tert-butanesulfinyl imidates was developed. Deprotonation of N- tert-butanesulfinyl imidates with lithium hexamethyldisilazide generates aza-enolates that can be intercepted, with excellent diastereocontrol, by the inexpensive electrophilic fluorinating agent NFSI. This protocol was applied to the preparation of synthetically useful trans-2-fluoro-cyclohexamine with high enantiomeric purity (99.5% ee).
November 8, 2018: Journal of Organic Chemistry
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