- Selenium-catalyzed reductive carbonylation of 2-nitrophenols to 2-benzoxazolones
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2-Benzoxazolones or 2-benzimidazolones are synthesized in moderate to good yields in the presence of a base (KOH, NaOH, KOAc, NEt3, DBU) at atmospheric pressure or under a high pressure of CO by one-pot reductive carbonylation of 2-nitrophenols or 2-nitroaniline in the presence of selenium as catalyst. Besides the effect of base, the effects of solvent and temperature on the reaction were investigated at high or atmospheric pressure. Contrasting results were obtained for 2-benzoxazolones or 2-benzimidazolone at high and atmospheric pressures. Moreover, phase-transfer catalysis was exhibited. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.
- Wang, Xiaofang,Ling, Gang,Xue, Yan,Lu, Shiwei
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- Selenium-catalyzed oxidative carbonylation of 2-aminobenzyl alcohol to give 1,4-dihydro-2 H -3,1-benzoxazin-2-one
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An efficient, economical, and phosgene-free approach was developed for the preparation of 1,4-dihydro-2H-3,1-benzoxazin-2-one from 2-aminobenzyl alcohol. In terms of its key features, this reaction uses the cheap and recyclable non-metal selenium as a catalyst instead of the noble metal palladium; carbon monoxide as a carbonylation agent instead of virulent phosgene or one of its derivatives; and oxygen as an oxidant. The selenium-catalyzed oxidative carbonylation reaction of 2-aminobenzyl alcohol proceeded efficiently in a single pot in the presence of triethylamine to afford 1,4-dihydro-2H-3,1-benzoxazin-2-one in 87% yield. Furthermore, the selenium catalyst was readily recovered and recycled, affording a product yield of 80% after five cycles.
- Zhang, Xiaopeng,Wang, Ping,Niu, Xueli,Li, Zhengwei,Fan, Xuesen,Zhang, Guisheng
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- Synthesis of 1,4-dihydro-benzo[d][1,3]oxazin-2-ones from phthalides via an aminolysis-Hofmann rearrangement protocol
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A simple two-step procedure for the conversion of readily available phthalides to the corresponding benzoxazinones was developed. Initial ring-opening aminolysis to form a primary 2-hydroxymethylbenzamide, followed by reaction with bis(trifluoroacetoxy)iodobenzene (BTI) conveniently, provided a variety of 4-substituted benzoxazinones.
- Hernández, Eliud,Vélez, Jessica M.,Vlaar, Cornelis P.
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- Synthesis of benzo-fused five- and six-membered heterocycles by palladium-catalyzed cyclocarbonylation
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A novel and simple synthetic methodology, based on palladium-catalyzed cyclocarbonylation reaction, is presented for preparing five- and six-membered benzo-fused heterocycles. A mechanism for the process is also proposed and discussed.
- Troisi, Luigino,Granito, Catia,Perrone, Serena,Rosato, Francesca
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- Synthesis of fullerotetrahydroquinolines by cycloaddition reaction of C60 with aza-ortho-xylylenes
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This paper reports on the successful synthesis of fullerotetrahydroquinolines by using in sire generated aza-ortho-xylylenes using a Diels-Alder reaction.
- Ohno, Masatomi,Sato, Haruhiko,Eguchi, Shoji
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- Metal catalyzed deoxygenation by carbon monoxide of o-substituted nitrobenzenes. Synthesis of 1,4-dihydro-2H-3,1-benzoxazin-2-one derivatives
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The reductive carbonylation of o-nitrobenzylalcohols, o-NO2C6H4CR1R2OH 1 = R2 = H (1); R1 = R2 = CH3 (2); R1 = H, R2 = CH3 (3); R1 = H, R2 = C6H5 (4)>, catalyzed by ruthenium and palladium-based catalytic systems gives the corresponding 1,4-dihydro-2H-3,1-benzoxazin-2-one derivatives, 1a-4a.Reaction conditions used were 20-60 atm of carbon monoxide and 100-170 deg C.The palladium catalyst has been shown to be far superior to the ruthenium catalyst in this reaction as far as selectivity is concerned.By carbonylation of o-nitrophenethylalcohol (5) with the palladium system as catalyst a mixture of the monomeric 5a and dimeric 5b cyclic carbamates has been obtained.
- Cenini, S.,Console, S.,Crotti, C.,Tollari, S.
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- A new synthetic method of 1,4-dihydro-2h-3,1-benzoxazin-2-ones: Selenium-catalyzed reductive carbonylation of aromatic nitro compounds with carbon monoxide
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It was confirmed that selenium catalyzed the reaction of 2-nitrobenzyl alcohols with carbon monoxide to afford 1,4-dihydro-2H-3,1-benzoxazin-2-ones in good yields. Similarly, seven-membered cyclic carbamate was prepared by the reaction of 2-(2-nitrophenyl)ethanol with carbon monoxide.
- Nishiyama, Yutaka,Naitoh, Yoshitaka,Sonoda, Noboru
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- Electrochemical access to benzimidazolone and quinazolinone derivatives: Via in situ generation of isocyanates
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Isocyanates are the key intermediates for several organic transformations towards the synthesis of diverse pharmaceutical targets. Herein, we report the development of an oxidant-free protocol for electrochemical in situ generation of isocyanates. This strategy highlights expedient access to benzimidazolones and quinazolinones and eliminates the need for exogenous oxidants. Furthermore, detailed mechanistic studies provide strong support towards our hypothesis of in situ isocyanate generation. This journal is
- Saha, Debarshi,Taily, Irshad Maajid,Naik, Sumitra,Banerjee, Prabal
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p. 631 - 634
(2021/01/29)
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- INHIBITORS OF PHOSPHOLIPID SYNTHESIS AND METHODS OF USE
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Inhibitors of Glycerol 3-Phosphate Acyltransferase (GPAT) are provided; and methods of use in the treatment of cancer; and treatment of conditions relating to metabolic syndrome, hyperlipidemia, infection and inflammation.
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Page/Page column 93
(2021/02/26)
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- Versatile Cp*Co(III)(LX) Catalyst System for Selective Intramolecular C-H Amidation Reactions
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Herein, we report the development of a tailored cobalt catalyst system of Cp*Co(III)(LX) toward intramolecular C-H nitrene insertion of azidoformates to afford cyclic carbamates. The cobalt complexes were easy to prepare and bench-stable, thus offering a convenient reaction protocol. The catalytic reactivity was significantly improved by the electronic tuning of the bidentate LX ligands, and the observed regioselectivity was rationalized by the conformational analysis and DFT calculations of the transition states. The superior performance of the newly developed cobalt catalyst system could be broadly applied to both C(sp2)-H and C(sp3)-H carbamation reactions under mild conditions.
- Chang, Sukbok,Jung, Hoimin,Kim, Dongwook,Lee, Jeonghyo,Lee, Jia,Park, Juhyeon
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supporting information
p. 12324 - 12332
(2020/08/06)
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- Concise and Additive-Free Click Reactions between Amines and CF3SO3CF3
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Trifluoromethyl trifluoromethanesulfonate has proved to be an excellent reservoir of difluorophosgene and a promising click ligation for amines in the preparation of urea derivatives, heterocycles, and carbamoyl fluorides under metal- and additive-free conditions. The reactions are rapid, efficient, selective, and versatile, and can be performed in benign solvents, giving products in excellent yields with minimal efforts for purification. The characteristics of the reactions meet the requirements of a click reaction. The use of trifluoromethyl trifluoromethanesulfonate as a click reagent is advantageous over other “CO” sources (e.g., TsOCF3, PhCO2CF3, CsOCF3, AgOCF3, and triphosgene) because this reagent is readily accessible; easy to scale up; and highly reactive, even under metal- and additive-free conditions. It is anticipated that CF3SO3CF3 will be increasingly as important as SO2F2 as a click agent in future drug design and development.
- Song, Hai-Xia,Han, Zhou-Zhou,Zhang, Cheng-Pan
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supporting information
p. 10907 - 10912
(2019/08/02)
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- The Reaction of o-Aminoacetophenone N-Tosylhydrazone and CO2 toward 1,4-Dihydro-2H-3,1-benzoxazin-2-ones
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A transition-metal-free reaction of o-aminoacetophenone N-tosylhydrazone and CO2 has been developed, leading to a series of 1,4-dihydro-2H-3,1-benzoxazin-2-ones in moderate to good yields. This procedure proceeds with the sequential fixation of CO2 by amino leading to carbamic acid and the intra- molecular insertion of hydroxyl to carbene. (Figure presented.).
- Xiong, Hao,Wu, Xiaopeng,Wang, Hepan,Sun, Song,Yu, Jin-Tao,Cheng, Jiang
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p. 3538 - 3542
(2019/07/10)
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- HIGH STRESS RESISTANT PLANT GROWTH REGULATOR AND PREPARATION METHOD AND USE THEREOF
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Disclosed are a high stress resistant plant growth regulator and a preparation and use thereof. In particular, the compound provided by the present invention is an ABA substitute for significantly improving the stress resistance of plants, and therefore has a very wide application prospect.
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Paragraph 0298-0300
(2019/01/15)
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- Carbon dioxide-based facile synthesis of cyclic carbamates from amino alcohols
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We report herein a straightforward general method for the synthesis of cyclic carbamates from amino alcohols and carbon dioxide in the presence of an external base and a hydroxyl group activating reagent. Utilizing p-toluenesulfonyl chloride (TsCl), the reaction proceeds under mild conditions, and the approach is fully applicable to the preparation of various high value-added 5- and 6-membered rings as well as bicyclic fused ring carbamates. DFT calculations and experimental results indicate a SN2-type reaction mechanism with high regio-, chemo-, and stereoselectivity.
- Niemi, Teemu,Fernández, Israel,Steadman, Bethany,Mannisto, Jere K.,Repo, Timo
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supporting information
p. 3166 - 3169
(2018/03/28)
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- CARBAMATE QUINABACTIN
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The present invention relates to novel sulfonamide derivatives, to processes and intermediates for preparing them, to plant growth regulator compositions comprising them and to methods of using them for controlling the growth of plants, improving plant tolerance to abiotic stress (including environmental and chemical stresses), inhibiting seed germination and/or safening a plant against phytotoxic effects of chemicals.
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- Continuous Flow Synthesis of Carbonylated Heterocycles via Pd-Catalyzed Oxidative Carbonylation Using CO and O2 at Elevated Temperatures and Pressures
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A continuous-flow Pd-catalyzed oxidative carbonylation protocol utilizing CO and O2 gas for the synthesis of carbonylated heterocycles is described. The optimization of temperature, pressure, CO/O2 ratio, catalyst loading, and reaction time resulted in process intensified conditions for this transformation. The optimized continuous flow conditions (120 °C, 20 bar pressure, 24 min residence time) were used to prepare a number of benzoxazolone, 2-benzoxazolidinone, and other biologically and synthetically important five- and six-membered carbonylated heterocycles in good overall yield and purity (14 examples). The continuous-flow process enables the safe and scalable oxidative carbonylation using CO/O2 under elevated pressures and temperatures.
- Chen, Yuesu,Hone, Christopher A.,Gutmann, Bernhard,Kappe, C. Oliver
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p. 1080 - 1087
(2017/07/26)
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- Sunlight-Driven Forging of Amide/Ester Bonds from Three Independent Components: An Approach to Carbamates
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A photoredox catalytic route to carbamates enabled by visible irradiation (or simply sunlight) has been developed. This process leads to a novel approach to the construction of heterocyclic rings wherein the amide or ester motifs of carbamates were assembled from three isolated components. Large-scale experiments were realized by employing continuous flow techniques, and reuse of photocatalyst demonstrated the green and sustainable aspects of this method.
- Zhao, Yating,Huang, Binbin,Yang, Chao,Chen, Qingqing,Xia, Wujiong
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supporting information
p. 5572 - 5575
(2016/11/17)
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- Pyruvate kinase activators for use for increasing lifetime of the red blood cells and treating anemia
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Described herein are methods for using compounds that activate pyruvate kinase.
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Page/Page column 75; 76
(2015/12/01)
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- PdCl2 catalyzed efficient assembly of organic azides, CO, and alcohols under mild conditions: A direct approach to synthesize carbamates
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A simple and readily available PdCl2 catalyzed carbamate synthesis method via isocyanate generation and application in situ has been developed. This chemistry provides an efficient and practical approach to synthesize carbamates from simple organic azides, CO atmosphere and alcohols. The broad scope, mild and neutral conditions, and only N2 as the byproduct make this transformation very useful. Moreover, simple examples of modification of bioactive molecules and construction of macrocycles were achieved through this protocol. This journal is the Partner Organisations 2014.
- Ren, Long,Jiao, Ning
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supporting information
p. 3706 - 3709
(2014/04/03)
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- BICYCLIC PKM2 ACTIVATORS
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Compounds and compositions comprising compounds including formula (I) that activate pyruvate kinase M2 (PKM2) are described herein. Also described herein are methods of using the compounds that activate PKM2 in the treatment of cancer.
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(2012/07/13)
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- Method for Making Carbamates, Ureas and Isocyanates
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The present invention provides methods of forming carbamates, ureas, and isocyanates. In certain embodiments these methods include the step of reacting an amine with an ester-substituted diaryl carbonate to form an activated carbamate which can be further derivitized to form non-activated carbamate or a urea. The urea or carbamate can be subjected to a pyrolysis reaction to form isocyanate.
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(2010/05/13)
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- PROCESS FOR THE SYNTHESIS OF CYCLIC CARBAMATES
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The invention is directed to a process for the preparation of cyclic carbamates of formula (I) and/or a salt thereof, from the corresponding o-aminobenzyl alcohol and/or a salt thereof.
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Page/Page column 7
(2010/11/03)
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- AlCl3-DMF Complex as Catalyst in the Fredel-Crafts Reaction. The Reactivity of Anhydrides and Chlorides of Dicarboxylic Acids.
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This paper reports different examples of Friedel-Crafts acylation of various substrates with dicarboxylic acid chlorides (phthalic, isophthalic, and malonyl synthons) in the presence of the AlCl3-DMF complex as catalyst.When we reacted 2(3H)-benzothiazolone with phthalic anhydride in the presence of the AlCl3-DMF complex as catalyst in addition to the product of 6-substitution, 4-(2-carboxybenzoyl) 2(3H)-benzothiazolone was obtained as a contaminant.This is the first product ever obtained with a 4-substitution in the acylation of 2(3H)-benzothiazolone.
- Taverne, Thierry,Depreux, Patrick,Lasieur, Daniel,Henichart, Jean-Pierre,Poupaert, Jacques H.
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p. 791 - 802
(2007/10/03)
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- Diels-Alder reactions of N-sulfonyl substituted aza-ortho-xylylenes generated from the corresponding 1,4-dihydro-2H-3,1-benzoxazin-2-one derivatives
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N-Tosyl- and N-alkylidene-sulfonyl substituted 1,4-dihydro-2A-3,1-benzoxazin-2-ones 2c-g easily undergo thermal carbon dioxide extrusion leading to the aza-ortho-xylylenes 3c-g. The intermediates 3c,d can be trapped by electron-poor ethylenic and acetylenic dienophiles, giving tetrahydroquinoline and quinoline derivatives. The reactions of 2c with non-symmetrical dienophiles are completely regioselective. N-Alkylidenesulfonyl substituted aza-orthro-xylylenes 3f-g undergo intramolecular Diels-Alder reactions leading to the tricyclic compounds 10 and 11, while the aza-ortho-xylylene generated from 4-(hex-5-enyl)-N-(4-methylphenylsulfonyl)-1,4-tetrahydro-2H-3,1-benzoxazin-2-one undergoes a [1,5] hydrogen shift leading to N-[2-(1E)-hepta-1,6-dien-1-ylphenyl]-4-methylbenzenesulfonamide.
- Consonni, Roberto,Dalla Croce, Piero,Ferraccioli, Raffaella,La Rosa, Concetta
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p. 1809 - 1814
(2007/10/03)
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- BENZOXAZINE DERIVATIVES AS INHIBITORS OF LEUKOTRIENES
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The invention concerns a bicyclic heterocyclic compound of the formula I wherein Q is an optionally substituted 10-membered bicyclic heterocyclic moiety containing 1 or 2 N's and a further O or S heteroatom; A1 is a direct link to X1 or (1-3C)alkylene; X1 is oxy, thio, sulphinyl, sulphonyl or imino; Ar is optionally substituted phenylene or pyridylene; R1 is (1-4C)alkyl, (3-4C)alkenyl or (3-4C)alkynyl; and R2 and R3 together form a group of the formula -A2-X2-A3- which, together with the carbon atom to which A2 and A3 are attached, defines a ring having 5 to 7 ring atoms, wherein each of A2 and A3 is (1-3C)alkylene and X2 is oxy, thio, sulphinyl or sulphonyl; or a pharmaceutically-acceptable salt thereof. The compounds of the invention are inhibitors of the enzyme 5-lipoxygenase
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- A novel and efficient synthesis of 4H-3,1-benzoxazines by a tandem aza-Wittig/heterocumulene-mediated annulation strategy
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2-[(Triphenylphosphoranylidene)amino]benzyl alcohol 2 reacts with isocyanates or isothiocyanates in refluxing toluene to give the corresponding 2-alkyl(aryl)amino-4H-3,1-benzoxazines 5. Iminophosphorane 2 also reacts with carbon dioxide and carbon disulfide to give 4H-3,1-benzoxazin-2(1H)-one (6) and -thione (7), respectively.
- Molina,Arques,Molina
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- Oxidative Cyclization of Diamides by Phenyliodoso Acetate
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Carboxamides containing a suitably situated nucleophilic group (carboxamide, N-substituted carboxamide, or hydroxymethyl) undergo oxidation by phenyliodoso acetate to afford heterocyclic products through internal attack on the initially formed isocyanate.N-Substituted carboxamido groups are the least effective of these internal traps.Phenyliodoso acetate is much superior to lead(IV) acetate for oxidative cyclization of maleamide and various substituted propanediamides, but is not suitable for butanediamide.
- Beckwith, Athelstan L. J.,Dyall, Leonard K.
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p. 451 - 461
(2007/10/02)
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- Benzimidazolyl-sulfinyl-tetrahydroquinolines
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A hydroquinoline compound of the formula (1): STR1 wherein R1, R2, R3, A, l, m and n are as defined or its pharmaceutically acceptable salt, composition containing the compound and processes for preparing same are disclosed. The compound is useful as an antiulcer agent.
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- A New Synthesis of Cyclic Ureas, Cyclic Urethanes, and a Quinazolinedione. Selenium-Assisted Carbonylation of Aromatic Amines with Carbon Monoxide
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Five-, six-, and seven-membered cyclic ureas were synthesized in excellent yields from various aromatic diamines by reaction with carbon monoxide and a stoichiometric or excess amount of selenium in the presence of an oxidizing agent such as oxygen or dimethyl sulfoxide producing selectively the five- and six-membered cyclic ureas.In the case of 2-(2-aminoethyl)aniline under the catalytic conditions, intra- and intermolecular carbonylation competed resulting in the formation of a mixture of the seven-membered cyclic urea, 1,3,4,5-tetrahydro-2H-1,3-benzodiazepin-2-one and the acyclic urea, 1,3-bisurea.The distribution ratio of these two products varied depending on the reaction conditions, but selective formation of the cyclic urea was attained only when a stoichiometric or excess amount of selenium was used.In addition to the above diamino compounds, 2-carbamoylaniline, 2-amino-3-pyridinol, and 2-(hydroxymethyl)-aniline also underwent similar carbonylation to give 2,4(1H,3H)-quinazolinedione, oxazolopyridin-2-(3H)-one, and 1,4-dihydro-2H-3,1-benzoxazin-2-one, respectively.
- Yoshida, Tohru,Kambe, Nobuaki,Murai, Shinji,Sonoda, Noboru
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p. 1793 - 1800
(2007/10/02)
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- IMPROVED PROCEDURE FOR LITHIUM BOROHYDRIDE REDUCTION OF CYCLIC ANHYDRIDES TO LACTONES IN TETRAHYDROFURAN
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The rate of reduction of several cyclic anhydrides by lithium borohydride in tetrahydrofuran at 25 deg C has been studied.The reaction has been utilized for the rapid and selective conversion of cyclic anhydrides to lactones.
- Narasimhan, Srinivasan
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p. 131 - 135
(2007/10/02)
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