- Cysteine-Activated Small-Molecule H2Se Donors Inspired by Synthetic H2S Donors
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The importance of selenium (Se) in biology and health has become increasingly clear. Hydrogen selenide (H2Se), the biologically available and active form of Se, is suggested to be an emerging nitric oxide (NO)-like signaling molecule. Nevertheless, the research on H2Se chemical biology has technique difficulties due to the lack of well-characterized and controllable H2Se donors under physiological conditions, as well as a robust assay for direct H2Se quantification. Motivated by these needs, here, we demonstrate that selenocyclopropenones and selenoamides are tunable donor motifs that release H2Se upon reaction with cysteine (Cys) at pH 7.4 and that structural modifications enable the rate of Cys-mediated H2Se release to be tuned. We monitored the reaction pathways for the H2Se release and confirmed H2Se generation qualitatively using different methods. We further developed a quantitative assay for direct H2Se trapping and quantitation in an aqueous solution, which should also be operative for investigating future H2Se donor motifs. In addition, we demonstrate that arylselenoamide has the capability of Cys-mediated H2Se release in cellular environments. Importantly, mechanistic investigations and density functional theory (DFT) calculations illustrate the plausible pathways of Cys-activated H2Se release from arylselenoamides in detail, which may help understand the mechanistic issues of the H2S release from pharmacologically important arylthioamides. We anticipate that the well-defined chemistries of Cys-activated H2Se donor motifs will be useful for studying Se biology and for development of new H2Se donors and bioconjugate techniques.
- Cai, Xuekang,Cheng, Longhuai,Dong, Yalun,Huang, Haojie,Jiang, Chenyang,Kang, Xueying,Sang, Yueqian,Sun, Lu,Wen, Xin,Xi, Zhen,Yi, Long
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supporting information
p. 3957 - 3967
(2022/03/08)
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- Visible-Light-Induced Cycloaddition of α-Ketoacylsilanes with Imines: Facile Access to β-Lactams
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We report the synthesis of β-lactams from α-ketoacylsilanes and imines, which proceeds via a formal [2+2] photochemical cycloaddition with in situ generation of siloxyketene. This mild and operationally simple reaction proceeds in an atom-economic fashion with broad substrate scope, including aldimines, ketimines, hydrazones, and fused nitrogen heterocycles, affording a variety of important β-lactams with satisfactory diastereoselectivities in most cases. This reaction also features good functional-group tolerance, facile scalability and product diversification. Experimental and computational studies suggest that α-ketoacylsilanes can serve as photochemical precursors by engaging in a 1,3 silicon shift to the distal carbonyl group.
- Ye, Jian-Heng,Bellotti, Peter,Paulisch, Tiffany O.,Daniliuc, Constantin G.,Glorius, Frank
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supporting information
p. 13671 - 13676
(2021/05/11)
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- Visible Light-Promoted Aryl Azoline Formation over Mesoporous Organosilica as Heterogeneous Photocatalyst
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N-heterocyclic compounds demonstrate wide applications ranging from natural compound production to coordination chemistry. Usually, the synthesis of N-heterocyclic compounds is conducted under thermal conditions, mostly by Lewis acids or metal-containing compounds as molecular catalysts. Here, we report a photocatalytic route for aryl azoline formation by mesoporous organosilica as visible light-active and heterogeneous photocatalyst. Via formation of aromatic aldehydes with various amines, 2-phenyl-2-imidazoline, 2-phenyl-2-oxazoline, 2-phenyl-2-thiazoline and their derivatives could be formed with high conversion and selectivity. Additionally, the organosilica photocatalyst showed high stability and reusability.
- Wei, Wenxin,Li, Run,Huber, Niklas,Kizilsavas, G?nül,Ferguson, Calum T. J.,Landfester, Katharina,Zhang, Kai A. I.
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p. 3410 - 3413
(2021/05/29)
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- Microwave-Assisted Synthesis of 2-Substituted 2-Thiazolines and 5,6-Dihydro-4 H -1,3-thiazines
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An efficient and general method for the synthesis of 2-substituted thiazolines and 5,6-dihydro-4 H -1,3-thiazines is developed via microwave-assisted ring closure of ω-thioamidoalcohols promoted by ethyl polyphosphate (PPE). The cyclization reaction involves an S N 2-type mechanism and features the advantages of very short reaction times, high yields and a predictable stereochemical outcome. The acyclic precursors are prepared in high overall yields by an improved diacylation-thionation-saponification sequence from commercially available ω-amino alcohols. The whole process is metal-free and operationally simple.
- Bisceglia, Juan A.,Kilimciler, Natalia B.,Mancinelli, Michele,Mollo, María C.,Orelli, Liliana R.
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p. 1666 - 1679
(2020/06/01)
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- Cu(II) immobilized on Fe3O4@Agarose nanomagnetic catalyst functionalized with ethanolamine phosphate–salicylaldehyde schiff base: A magnetically reusable nanocatalyst for preparation of 2-substituted imidazolines, oxazolines, and thiazolines
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Herein we synthesized Cu(II) immobilized on Fe 3 O 4 @Agarose functionalized with ethanolamine phosphate–salicylaldehyde Schiff base (Fe 3 O 4 @Agarose/SAEPH 2 /Cu(II)) as a new and cost-effective nanomagnetic catalyst. The nanomagnetic catalyst was characterized by FT- IR, XRD, VSM, SEM- EDX, TEM, TGA, and ICP techniques and it was found that the particles were about 9–25 nm in size and spherical with entrapment of the Fe 3 O 4 particles in the hollow pore structure of the agarose. The prepared nanomagnetic catalyst showed excellent activity for preparation of 2-substituted imidazolines, oxazolines, and thiazolines. The catalyst is easy to prepare and exhibits higher catalytic activity than some commercially available copper sources. More importantly, this nanomagnetic catalyst can be easily recovered by using a permanent magnet and reused for at least seven cycles without significant deactivation.
- Zarei, Zeinab,Akhlaghinia, Batool
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p. 170 - 191
(2018/02/17)
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- Additive-free pd-catalyzed α-allylation of imine-containing heterocycles
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An additive-free Pd-catalyzed α-allylation of different imino-group-ontaining heterocycles is reported. The activation of α-CH pronucleophiles (pKa (DMSO) > 25) occurs without the addition of strong bases or Lewis acids using only the Pd/Xantphos catalyst system. The reaction scope has been studied for various 5- and 6-membered nitrogen-containing heterocycles (yields up to 96%). Mechanistic investigations suggest an initial allylation of the imine-N followed by a Pd-catalyzed formal aza-Claisen rearrangement.
- Kljajic, Marko,Puschnig, Johannes G.,Weber, Hansj?rg,Breinbauer, Rolf
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supporting information
p. 126 - 129
(2017/11/27)
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- Selective thioacylation of amines in water: A convenient preparation of secondary thioamides and thiazolines
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Primary thioamides have been utilised directly in water, without any derivatisation, to selectively thioacylate primary amines. By employing 2-hydroxyethylamines, the reaction can be extended to the preparation of 2-thiazolines via formation of β-hydroxythioamides.
- Pathak, Uma,Bhattacharyya, Shubhankar,Mathur, Sweta
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p. 4484 - 4488
(2015/02/19)
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- A single-reagent-driven multistep one-pot preparation of thiazolines and 1,3-thiazines from aldoximes, nitriles, and carboxylic acids
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N-(ω-Bromoalkyl)dichlorothiophosphoramidates have been designed as a new class of reagent for the single-reagent-driven multistep preparation of 2-substituted thiazolines and 1,3-thiazines from ald-oximes, nitriles, or carboxylic acids. A wide range of substrates both aromatic as well as aliphatic were investigated and found suitable for the developed protocol.
- Bhattacharyya, Shubhankar,Pathak, Uma
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p. 3553 - 3560
(2015/11/17)
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- A straightforward metal-free synthesis of 2-substituted thiazolines in air
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A base-catalysed procedure for the synthesis of 2-substituted thiazolines from nitriles and cysteamine hydrochloride under solvent-free conditions is presented. This straightforward approach allows high conversion for a broad range of nitriles and an easy
- Trose, Michael,Lazreg, Fa?ma,Lesieur, Mathieu,Cazin, Catherine S. J.
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supporting information
p. 3090 - 3092
(2015/05/27)
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- Fluoroalkanosulfonyl fluorides-mediated cyclodehydration of β-hydroxy sulfonamides and β-hydroxy thioamides to the corresponding aziridines and thiazolines
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An efficient method for the fluoroalkanosulfonyl fluoride-induced cyclodehydration of β-hydroxy sulfonamides and β-hydroxy thioamides to the corresponding aziridines and thiazolines is reported. Mild reaction conditions, operational simplicity, and high y
- Yan, Zhaohua,Guan, Chengbo,Yu, Zhangxin,Tian, Weisheng
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supporting information
p. 5788 - 5790
(2013/10/01)
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- DDQ-induced dehydrogenation of heterocycles for c-c double bond formation: Synthesis of 2-thiazoles and 2-oxazoles
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Strong as an Ox: 2-Thiazoles and 2-oxazoles are formed by oxidation of 2-thiazolines and 2-oxazolines without requiring substituents at the C4 and C5 positions. DDQ plays an important role as the oxidant in this transformation and metal is unnecessary. This general procedure shows good functional group tolerance and provides a wide variety of 2-thiazoles and 2-oxazoles in moderate to excellent yields.
- Li, Xiangnan,Li, Cheng,Yin, Bing,Li, Cong,Liu, Ping,Li, Jianli,Shi, Zhen
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supporting information
p. 1408 - 1411
(2013/07/26)
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- Tribromomelamine: A novel and efficient catalyst for the synthesis 2-arylthiazolines under solvent-free conditions
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A novel procedure for the synthesis of 2-arylthiazolines through one-pot condensation of of nitriles with 2-aminoethanethiol in the presence of tribromomelamine as catalyst under solvent-free conditions is described.
- Wu, Liqiang
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experimental part
p. 1035 - 1041
(2012/06/30)
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- One-pot synthesis of 2-arylthiazolines with 1-butyl-3-methylimidazolium tribromide as a catalytic reagent
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A simple, inexpensive, and efficient one-pot synthesis of 2-arylthiazoline derivatives under solvent-free conditions using a catalytic amount of 1-butyl-3-methylimidazolium tribromide with excellent product yields is reported. This methodology provides ea
- Lu, Guangzhou,Yang, Limin,Wu, Liqiang
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experimental part
p. 403 - 408
(2012/04/04)
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- Trichloroisocyanuric acid as an efficient homogeneous catalyst for the chemoselective synthesis of 2-substituted oxazolines, imidazolines and thiazolines under solvent-free condition
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Trichloroisocyanuric acid, as a commercially available and inexpensive catalyst, was used in a new, facile and efficient procedure for the synthesis of 2-oxazolines, 2-imidazolines and 2-thiazolines through the reaction of nitriles with 2-aminoethanol, ethylenediamine or 2-aminoethanethiol under solvent-free conditions.
- Hojati, Seyedeh Fatemeh,Nezhadhoseiny, Seyede Atefe
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p. 1181 - 1189,9
(2020/09/14)
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- Easy access to 2-alkyl and 2-arylthiazolines using a modified heteropolyacid catalysis: Application to the synthesis of bacillamide A
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A straightforward access to 2-alkyl and 2-arylthiazolines by condensation of-aminothiols on nitriles, catalyzed by phosphotungstic acid (2%) under microwave irradiation, is described. This method has been directly applied to a short and efficient synthesi
- Fache,Cros,Piva,Lefebvre
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experimental part
p. 2098 - 2109
(2012/06/04)
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- Solvent-free tandem synthesis of 2-thiazolines and 2-oxazolines catalyzed by a copper catalyst
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Tandem reactions of nitriles with 2-aminoethanethiol hydrochloride or amino alcohols in the presence of a catalytic amount of cupric methacrylate (Cu II2L4, L = methacrylate) were employed to prepare 2-thiazolines and 2-ox
- Li, Xiangnan,Zhou, Baoyue,Zhang, Jin,She, Mengyao,An, Shujuan,Ge, Haixia,Li, Cong,Yin, Bing,Li, Jianli,Shi, Zhen
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experimental part
p. 1626 - 1632
(2012/05/04)
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- Easy access to thiazolines and thiazines via tandem S-alkylation- cyclodeamination of thioamides/haloamines
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This is the first report of a facile synthesis of thiazolines and thiazines from a self-catalyzed, water assisted tandem S-alkylation-cyclodeamination reaction of thioamides/haloamines. The reaction is clean and efficient with simple product work-up, and is applicable to a variety of substrates.
- Pathak, Uma,Bhattacharyya, Shubhankar,Dhruwansh, Vishwanath,Pandey, Lokesh Kumar,Tank, Rekha,Suryanarayana, Malladi V. S.
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supporting information; experimental part
p. 1648 - 1651
(2011/08/10)
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- 1,3-Dibromo-5,5-dimethylhydantoin as an efficient homogeneous catalyst for the synthesis of 2-arylthiazolines and 2-arylimidazolines
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A simple, facile, and efficient procedure for the synthesis of 2-arylthizolines and 2-arylimidazolines has been developed by the simple condensation of nitriles with 2-aminoethanethiol or ethylenediamine catalyzed by 1,3-dibromo-5,5-dimethylhydantoin under solvent-free conditions. Selective preparation of bisthiozolines and monoimidazolines from dinitriles and also selective conversion of arylnitriles to their corresponding 2-arylthiazolines or imidazolines in the presence of alkylnitriles can be considered as considerable advantages of this method.
- Hojati, Seyedeh Fatemeh,Mohammadpoor-Baltork, Iraj,Maleki, Behrooz,Gholizadeh, Mostafa,Shafiezadeh, Fatemeh,Haghdoust, Mahnaz
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experimental part
p. 135 - 141
(2010/04/04)
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- The use of phosphonium anhydrides for the synthesis of 2-oxazolines, 2-thiazolines and 2-dihydrooxazine under mild conditions
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β-Hydroxy amides 6 and 7 were treated with triphenylphosphonium anhydride trifluoromethane sulfonate (3), or the cyclic analogue 4, to generate 2-oxazolines 5 and 8 under mild conditions. The reaction was optimised by examining the number of equivalents of reagents 3 or 4, or diisopropylethyl amine required to best effect cyclisation. The effects of altering the reaction temperature, reaction time, concentration, solvent, and addition rate also were investigated. However, it was found that use of a trityl group to block reaction at the hydroxyl or thiol group of the starting amides, and subsequent in situ detritylation, in the absence of base, led to greatly improved yields. Reagent 4 offered significant advantages in the purification of products and was used to dehydrate a range of trityl derivatives to form simple oxazolines, thiazolines, and a dihydro-1,3-oxazine, in high yield (85-99%), as well as a tetrahydro-1,3-oxazepine (31%).
- Petersson, Maria J.,Jenkins, Ian D.,Loughlin, Wendy A.
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supporting information; experimental part
p. 739 - 746
(2009/06/20)
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- Straightforward microwave-assisted synthesis of 2-thiazolines using Lawesson's reagent under solvent-free conditions
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2-Thiazolines are synthesized from carboxylic acids and 1,2-aminoalcohols in the presence of Lawesson's reagent under solventless conditions. The developed method is valid for either substituted or unsubstituted aminoalcohols and a wide variety of aromatic, heteroaromatic and aliphatic carboxylic acids; thus it constitutes a general synthetic method for these kinds of compounds. The role of Lawesson's reagent is dual: to transform the 1,2-aminoalcohol into 1,2-aminothiol and to activate its reaction with the carboxylic acid leading to the formation of a thiazoline ring, all in one pot.
- Seijas, Julio A.,Vázquez-Tato, M. Pilar,Crecente-Campo, José
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p. 9280 - 9285
(2008/12/21)
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- Synthesis of thiazolines by the reaction of aryl ketonitriles with cysteamine via microwave irradiation
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(Chemical Equation Presented) Thiazolines were synthesized in a one-pot reaction in excellent yield using a newly developed methodology. Ketonitriles were directly condensed with cysteamine (2-amino-thioalcohol) via microwave irradiation at 210°C for 10 m
- Kamila, Sukanta,Biehl, Edward R.
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p. 407 - 409
(2008/03/29)
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- Synthesis of 2-oxazolines and 2-thiazolines using lanthanide amino alkoxide
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New 2-oxazolines and 2-thiazolines are prepared from phenacysulfonylacetic acid methyl ester using lanthanide amino alkoxide. Copyright Taylor & Francis Group, LLC.
- Padmavathi,Reddy, B. Chandra Obula,Thriveni,Mohan, A.V. Nagendra
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p. 3127 - 3142
(2008/02/13)
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- Thionation of N-(ω-halogenoalkyl)-substituted amides with Lawesson's reagent: Facile synthesis of 4,5-dihydro-1,3-thiazoles and 5,6-dihydro-4H-1,3- thiazines
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The thionation and cyclization of N-(ω-halogenoalkyl)-substituted amides (and related compounds) with Lawesson's reagent (LR = 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide) has been investigated. Treatment of the amides 1 with LR gav
- Kodama, Yasuhiro,Ori, Mayuko,Nishio, Takehiko
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p. 187 - 193
(2007/10/03)
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- Facile Syntheses of Oxazolines and Thiazolines with N-Acylbenzotriazoles under Microwave Irradiation
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Microwave reactions of 2-amino-2-methyl-1-propanol (2) or 2-aminoethanethiol hydrochloride (4) with readily available N-acylbenzotriazoles 1a-j in the presence of SOCl2 produced 2-substituted 2-oxazolines 3a-j in 84-98% yields and 2-substituted
- Katritzky, Alan R.,Cai, Chunming,Suzuki, Kazuyuki,Singh, Sandeep K.
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p. 811 - 814
(2007/10/03)
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- A new method for the preparation of nitrogen-containingheterocycles using diphenylsulfonium triflates
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Various nitrogen heterocycles were produced by the reactions of ω-bromoalkyldiphenylsulfonium or diphenylsyylsulfonium triflates with nitrogen nucleophiles. Further, the reactions of diphenylstyrylsulfonium triflates with N-metalated phthalimide and imida
- Yamanaka, Hiroyuki,Yamane, Yoshinobu,Mukaiyama, Teruaki
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p. 2813 - 2826
(2007/10/03)
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- Novel synthesis of 2-thiazolines
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The synthesis of a series of 2-thiazolines was carried out under mild conditions from the corresponding thiazolidines, by a Ru-catalyzed/TBHP oxidation reaction conditions. The reaction was chemoselective towards the amine-imine oxidation and was also regioselective, affording the unsaturation at the 2-position of the heterocycle, even with thiazolidine substrates bearing ester groups at the 4-position. (C) 2000 Elsevier Science Ltd.
- Fernandez, Xavier,Fellous, Roland,Du?ach, Elisabet
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p. 3381 - 3384
(2007/10/03)
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- Synthetic studies of thiazoline and thiazolidine-containing natural products - 1. Phosphorus pentachloride-mediated thiazoline construction reaction
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Phosphorus pentachloride effectively mediates the cyclization of N- acylcysteamine derivatives giving rise to thiazoline rings. Using this method, sterically hindered thiazoline analogs could be constructed and thus segment A (the left half) of micacocidin, a unique antimycoplasma antibiotic, was synthesized efficiently.
- Ino, Akira,Murabayashi, Akira
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p. 10271 - 10282
(2007/10/03)
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- A one step synthesis of thiazolines from esters
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Condensation of the triisobutylaluminum complex of cysteamine HCl with a variety of carboxylic esters furnishes thiazolines in one step. This new method has been applied to chiral α-aminoesters to give α-amino thiazolines of high optical purity, yet N-ben
- Busacca, Carl A.,Dong, Yong,Spinelli, Earl M.
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p. 2935 - 2938
(2007/10/03)
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- A simple synthesis of Δ2-oxazolines, Δ2-oxazines, Δ2-thiazolines and 2-substituted benzoxazoles
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Carboxylic acids react readily at 0° ← + 24°C with amino alcohols, amino mercaptans and o-aminophenols in the presence of triphenylphosphine- or tributylphosphine dichloride (generated in situ from the reaction of the phosphines with hexacholoroethane or CCl4) and triethylamine in acetonitrile to form the corresponding Δ2-oxazolines, Δ2-oxazines, Δ2-thiazolines and 2-substituted benzoxazoles in one reaction step in yields of up to 80%.
- Vorbruggen,Krolikiewicz
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p. 9353 - 9372
(2007/10/02)
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- CARBON TRANSFER REACTIONS OF Δ2-OXAZOLINIUM AND THIAZOLINIUM CATIONS
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Δ2-Oxazolinium and thiazolinium cations with or without an appendage at any of the heteroatoms transfer their C(2) units at the carboxylic acid oxidation level to binucleophiles and provide the corresponding heterocycles, thus mimicking carbon transfer reactions exhibited by THF models, N-methyl N'-tosyl/acetyl imidazolinium cations.However, these azolinium cations react with phenethylamine and tryptamine to furnish their N-acyl derivatives.
- Singh, Harjit,Sarin, Rakesh
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p. 1449 - 1460
(2007/10/02)
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- Heterocyclic Ring Interchange Reactions
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Δ2-Oxazolinium and thiazolinium cations transfer their C(2) units to acyclic binucleophiles to furnish ring interchange non-aromatic heterocycles.
- Singh, Harjit,Sarin, Rakesh
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- Research on radioprotective agents: Δ-2 Thiazolines and homologous derivatives
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Compounds derived from Δ-2 thiazoline, Δ-2 thiazolinium iodoalkylate and 4,5-dihydro-1,3 thiazine have been prepared and evaluated as potential antiradiation agents in mice. They generally have a low toxicity and significant radioprotective activity.
- Robbe,Fernandez,Chapat,et al.
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- A SIMPLE SYNTHESIS OF Δ2-OXAZOLINES, Δ2-OXAZINES, Δ2-THIAZOLINES AND Δ2-IMIDAZOLINES
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Carboxylic acids react with amino alcohols, amino mercaptans or diamines in the presence of triphenylphosphine, CCl4 and tert. bases to afford in 50-75percent yield the corresponding Δ2-oxazolines, Δ2-oxazines, Δ2-thiazolines and Δ2-imidazolines.
- Vorbrueggen, Helmut,Krolikiewicz, Konrad
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p. 4471 - 4474
(2007/10/02)
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