- N-Methylphenothiazine S-Oxide Enabled Oxidative C(sp2)–C(sp2) Coupling of Boronic Acids with Organolithiums via Phenothiaziniums
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Herein, we report the development of a transition-metal-free oxidative C(sp2)–C(sp2) coupling of readily available boronic acids and organolithiums via phenothiazinium ions. Various biaryl, styrene, and diene derivatives were obtained using this reaction system. The key to this process is N-methylphenothiazine S-oxide (PTZSO), which allows efficient conversion of boronic acids to phenothiazinium ions. The mechanism of phenothiazinium formation using PTZSO was investigated using theoretical calculations and experiments, which provided insight into the unique reactivity of PTZSO.
- Yoshida, Tatsuki,Honda, Yuki,Morofuji, Tatsuya,Kano, Naokazu
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p. 9664 - 9668
(2021/12/17)
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- Ligand-controlled iridium-catalyzed semihydrogenation of alkynes with ethanol: highly stereoselective synthesis of E- and Z-alkenes
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A ligand-controlled iridium-catalyzed semihydrogenation of alkynes to E- and Z-alkenes with ethanol was developed. Effective selectivity control was achieved by ligand regulation. The use of 1,2-bis(diphenylphosphino)ethane (DPPE) and 1,5-cyclooctadiene (COD) was critical for the stereoselective semihydrogenation of alkynes. The general applicability of this procedure was highlighted by the synthesis of more than 40 alkenes, with good stereoselectivities. The value of our approach in practical applications was investigated by studying the effects of pinosylvin and 4,4′-dihydroxystilbene (DHS) on zebrafish as a vertebrate model.
- Yang., Jinfei,Wang, Chengniu,Sun, Yufeng,Man, Xuyan,Li, Jinxia,Sun, Fei
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supporting information
p. 1903 - 1906
(2019/05/02)
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- Novel Carbazole-Based N-Heterocyclic Carbene Ligands to Access Synthetically Relevant Stilbenes in Pd-Catalyzed Coupling Processes
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A series of new carbazole-based N-heterocyclic carbene (NHC) ligands have been synthesized in a simple and facile synthetic route and subsequently used in a Pd/carbazole-based NHC catalytic system, which was found to be effective in catalyzing Heck reactions to provide substituted stilbene derivatives in good yields. Several bioactive stilbenes, including pterostilbene, pinosylvin, trimethoxy resveratrol, and resveratrol, were synthesized in good yields, and a 10 mmol scale-up was also performed for trimethoxy resveratrol. The synthetic application was also extended by performing a double-tandem chemoselective Heck reaction followed by Miyaura borylation in a one-pot procedure to give single-step access to synthetically useful stilbenyl boronate esters. Similarly, a unique triple-tandem protocol of a chemoselective Heck reaction/Miyaura borylation/Suzuki–Miyaura coupling reaction sequence was performed for the one-pot modification of biologically relevant molecules.
- Girase, Tejpalsingh Ramsingh,Kapdi, Anant R.
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supporting information
p. 2611 - 2619
(2019/07/05)
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- Piperidine-appended imidazolium ionic liquid as task-specific basic-IL for Suzuki and Heck reactions and for tandem Wittig-Suzuki, Wittig-Heck, Horner-Emmons-Suzuki, and Horner-Emmons-Heck protocols
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Facile, high yielding, one-pot methods for the synthesis of a library of diversely substituted bi-aryls, diarylethenes, and aryl-enoates, via Suzuki and Heck reactions, and by sequential Wittig-Suzuki, Wittig-Heck, Horner-Emmons-Suzuki, and Horner-Emmons-Heck reactions are reported. The reactions employ piperidine-appended imidazolium ionic liquid [PAIM][NTf2] as a task-specific basic-IL, butyl-methyl-imidazolium ionic liquid [BMIM][X] (X?=?PF6, BF4) as solvent, and catalytic amounts of Pd(OAc)2 with no other additives. Wittig and Horner-Emmons reactions are effected by reacting substituted benzaldehydes with 4-bromobenzyl-PPh3 (or bromomethyl-PPh3) phosphonium salts, or diethylphosphonate with bromobenzaldehydes respectively, to form the corresponding ethenes. Subsequent cross-coupling reactions are accomplished by addition of aryl-boronic acid or phenyl-ethenes along with Pd(OAc)2 to bring about the aforementioned hyphenated transformations. The feasibility to perform double-olefination via Wittig and Horner-Emmons reactions with dialdehydes to form highly conjugated bis-styryl and bis-enoate compounds is also shown. The [BMIM][X] solvent is recycled and reused.
- Savanur, Hemantkumar M.,Kalkhambkar, Rajesh G.,Laali, Kenneth K.
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p. 150 - 161
(2017/06/30)
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- Synthesis of stilbene derivatives via visible-light-induced cross-coupling of aryl diazonium salts with nitroalkenes using-NO2 as a leaving group
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The straightforward visible-light-induced synthesis of stilbene compounds via the cross-coupling of nitroalkenes and diazonium tetrafluoroborates under transition-metal-free conditions is described. The protocol uses green LEDs as light sources and eosin Y as an organophotoredox catalyst. Broad substrate scope and exclusive selectivity for the (E)-configuration of stilbenes are observed. This protocol proceeds via a radical pathway, with nitroalkenes serving as the radical acceptor, and the nitro group is cleaved during the process.
- Zhang, Na,Quan, Zheng-Jun,Zhang, Zhang,Da, Yu-Xia,Wang, Xi-Cun
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supporting information
p. 14234 - 14237
(2016/12/14)
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- Heck-Matsuda reaction of arenediazonium salts in water
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The palladium-catalyzed arylation of alkenes with aryldiazonium salts can be carried out through an environmentally friendly protocol using neat water low palladium loadings at room temperature under base-additive- and ligand-free conditions.
- Salabert, Jordi,Sebastián, Rosa María,Vallribera, Adelina,Cívicos, José Francisco,Nájera, Carmen
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p. 2655 - 2659
(2013/03/28)
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- 1-(α-Aminobenzyl)-2-naphthol as phosphine-free ligand for Pd-catalyzed Suzuki and one-pot Wittig-Suzuki reaction
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Air stable and easily accessible, 1-(α-aminobenzyl)-2-naphthols are used as efficient phosphine-free ligands in palladium-catalyzed Suzuki reaction for a variety of substrates under conventional heating as well as ultrasonic conditions. Multi-brominated aromatic substrates were successfully converted to corresponding arylated moieties with good conversion and selectivity. A novel one-pot two-step cascade reaction strategy involving Wittig and Suzuki reactions is developed for efficient synthesis of 4-styryl biphenyls (C 6-C2-C6-C6 unit). Copyright 2012 John Wiley & Sons, Ltd. Phosphine free 1-(α-aminobenzyl)-2- naphthol ligands are used for Pd catalyzed Suzuki and one-pot Wittig-Suzuki reaction to efficiently prepare styryl biphenyls (C6-C 2-C6-C6 unit). Copyright
- Chaudhary,Bedekar
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experimental part
p. 430 - 437
(2012/09/22)
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- Copper-catalyzed alkene arylation with diaryliodonium salts
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Alkenes and arenes represent two classes of feedstock compounds whose union has fundamental importance to synthetic organic chemistry. We report a new approach to alkene arylation using diaryliodonium salts and Cu catalysis. Using a range of simple alkenes, we have shown that the product outcomes differ significantly from those commonly obtained by the Heck reaction. We have used these insights to develop a number of new tandem and cascade reactions that transform readily available alkenes into complex arylated products that may have broad applications in chemical synthesis.
- Phipps, Robert J.,McMurray, Lindsay,Ritter, Stefanie,Duong, Hung A.,Gaunt, Matthew J.
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supporting information; experimental part
p. 10773 - 10776
(2012/08/07)
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- Rh catalyzed c-h activation and oxidative olefination without chelate assistance: On the reactivity of bromoarenes
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A Rh catalyzed, no-chelate-assisted C-H activation/oxidative olefination reaction of bromoarenes has been discovered, in which the latter ones seem to act as a substrate, terminal oxidant, and catalyst modifier.
- Patureau, Frederic W.,Nimphius, Corinna,Glorius, Frank
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supporting information; experimental part
p. 6346 - 6349
(2012/01/15)
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- METHODS FOR TREATING OR PREVENTING NEOPLASIAS
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The present invention is directed to a method for treating or preventing a neoplasia in a human patient in need of such treatment comprising administering to the patient a compound that inhibits microsomal prostaglandin E synthase-1 in an amount that is effective for treating or preventing the neoplasia.
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Page/Page column 44
(2008/06/13)
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- METHOD OF GENERATING AMORPHOUS SOLID FOR WATER-INSOLUBLE PHARMACEUTICALS
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The invention encompasses a method for making an amorphous solid of a water-insoluble pharmaceutical comprising: (1) dissolving the water-insoluble pharmaceutical in a water-miscible solvent, optionally with water, to make a solution; (2)(i) rapidly mixing the solution with an antisolvent, wherein the antisolvent is water, at low temperature to precipitate an amorphous solid of the water-insoluble pharmaceutical, or (ii) rapidly mixing the solution with an antisolvent, wherein the antisolvent is water, to precipitate an amorphous solid of the water-insoluble pharmaceutical and subsequently cooling to low temperature; and (3) isolating the amorphous solid of the water-insoluble pharmaceutical. In an embodiment of the invention, the rapid mixing is conducted using an impinging jet device.
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Page/Page column 7
(2008/06/13)
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- 2-(PHENYL OR HETEROCYCLIC)-1H-PHENANTRHO[9,10-D]IMIDAZOLES AS MPGES-1 INHIBITORS
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The invention encompasses novel compounds of Formula (I) or pharmaceutically acceptable salts thereof. These compounds are inhibitors of the microsomal prostaglandin E synthase-1 (mPGES-1) enzyme and are therefore useful to treat pain and/or inflammation from a variety of diseases or conditions, such as osteoarthritis, rheumatoid arthritis and acute or chronic pain. Methods of treating diseases or conditions mediated by the mPGES-1 enzyme and pharmaceutical compositions are also encompassed
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Page/Page column 39
(2008/06/13)
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- 2-(PHENYL OR HETEROCYCLIC) - 1H-PHENANTHRO [9,10-D] IMIDAZOLES
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The invention encompasses novel compounds of Formula (I) or pharmaceutically acceptable salts thereof. These compounds are inhibitors of the microsomal prostaglandin E synthase-1 (mPGES-1) enzyme and are therefore useful to treat pain and/or inflammation from a variety of diseases or conditions, such as osteoarthritis, rheumatoid arthritis and acute or chronic pain. Methods of treating diseases or conditions mediated by the mPGES-1 enzyme and pharmaceutical compositions are also encompassed.
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Page/Page column 51
(2008/06/13)
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- Synthesis of (E)-alkenes via hydroindation of C{triple bond, long}C in InCl3-NaBH4 system
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In InCl3-NaBH4-MeCN system, terminal aryl alkynes could couple with aryl iodides and bromides to give disubstituted alkenes via hydroindation of C{triple bond, long}C. In the similar way, (E)-alkenylsilanes were synthesized via reduction of alkynylsilanes in tetrahydrofuran (THF) in high yields. The processes showed high regio- and stereoselectivity.
- Wang, Chunyan,Yan, Lei,Zheng, Zhiguo,Yang, Deyu,Pan, Yuanjiang
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p. 7712 - 7717
(2007/10/03)
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- 2-(PHENYL OR HETEROCYCLIC)-1H-PHENANTRHO[9,10-D]IMIDAZOLES AS MPGES-1 INHIBITORS
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The invention encompasses novel compounds of Formula I INSERT FORMULA I FROM CLAIM 1 or pharmaceutically acceptable salts thereof. These compounds are inhibitors of the microsomal prostaglandin E synthase-1 (mPGES-1) enzyme and are therefore useful to treat pain and/or inflammation from a variety of diseases or conditions, such as osteoarthritis, rheumatoid arthritis and acute or chronic pain. Methods of treating diseases or conditions mediated by the mPGES-1 enzyme and pharmaceutical compositions are also encompassed.
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Page/Page column 30-31
(2008/06/13)
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- Spectroscopic Correlations between Supermolecules and Molecules. Anatomy of the Ion-Modulated Electronic Properties of the Nitrogen Donor in Monoazacrown-Derived Intrinsic Fluoroionophores
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The synthesis, absorption and emission spectra, fluorescence quantum yields, and fluorescence lifetimes of three compound series of trans-4,4′-disubstituted aminostilbenes (1-3) are reported. The chromo-/fluoroionophoric behavior of the monoaza-15-crown-5
- Yang, Jye-Shane,Hwang, Chung-Yu,Hsieh, Chia-Chun,Chiou, Shih-Yi
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p. 719 - 726
(2007/10/03)
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- Platinum-catalyzed cross-couplings of organoboronic acids with aryl iodides
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Tetrakis(triphenylphosphine)platinum in DMF was utilized as a mild catalyst for cross coupling reactions of organoboronic acids with aryl iodides. The present reactions exhibited excellent group-selectivity where couplings of organoboronic acids 2a-e with 4-bromo-1-iodobenzene (4) give 4-arylbromobenzenes 5a-b and 4-alkenylbromobenzenes 5c-e in excellent yields.
- Oh, Chang Ho,Lim, Young Mook,You, Choong Ho
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p. 4645 - 4648
(2007/10/03)
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