2722-34-1Relevant academic research and scientific papers
Cysteine-Activated Small-Molecule H2Se Donors Inspired by Synthetic H2S Donors
Cai, Xuekang,Cheng, Longhuai,Dong, Yalun,Huang, Haojie,Jiang, Chenyang,Kang, Xueying,Sang, Yueqian,Sun, Lu,Wen, Xin,Xi, Zhen,Yi, Long
supporting information, p. 3957 - 3967 (2022/03/08)
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.
Visible-Light-Induced Cycloaddition of α-Ketoacylsilanes with Imines: Facile Access to β-Lactams
Ye, Jian-Heng,Bellotti, Peter,Paulisch, Tiffany O.,Daniliuc, Constantin G.,Glorius, Frank
supporting information, p. 13671 - 13676 (2021/05/11)
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.
Visible Light-Promoted Aryl Azoline Formation over Mesoporous Organosilica as Heterogeneous Photocatalyst
Wei, Wenxin,Li, Run,Huber, Niklas,Kizilsavas, G?nül,Ferguson, Calum T. J.,Landfester, Katharina,Zhang, Kai A. I.
, p. 3410 - 3413 (2021/05/29)
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.
Microwave-Assisted Synthesis of 2-Substituted 2-Thiazolines and 5,6-Dihydro-4 H -1,3-thiazines
Bisceglia, Juan A.,Kilimciler, Natalia B.,Mancinelli, Michele,Mollo, María C.,Orelli, Liliana R.
, p. 1666 - 1679 (2020/06/01)
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.
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
Zarei, Zeinab,Akhlaghinia, Batool
, p. 170 - 191 (2018/02/17)
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.
Additive-free pd-catalyzed α-allylation of imine-containing heterocycles
Kljajic, Marko,Puschnig, Johannes G.,Weber, Hansj?rg,Breinbauer, Rolf
supporting information, p. 126 - 129 (2017/11/27)
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.
A single-reagent-driven multistep one-pot preparation of thiazolines and 1,3-thiazines from aldoximes, nitriles, and carboxylic acids
Bhattacharyya, Shubhankar,Pathak, Uma
, p. 3553 - 3560 (2015/11/17)
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.
Selective thioacylation of amines in water: A convenient preparation of secondary thioamides and thiazolines
Pathak, Uma,Bhattacharyya, Shubhankar,Mathur, Sweta
, p. 4484 - 4488 (2015/02/19)
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.
A straightforward metal-free synthesis of 2-substituted thiazolines in air
Trose, Michael,Lazreg, Fa?ma,Lesieur, Mathieu,Cazin, Catherine S. J.
supporting information, p. 3090 - 3092 (2015/05/27)
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
DDQ-induced dehydrogenation of heterocycles for c-c double bond formation: Synthesis of 2-thiazoles and 2-oxazoles
Li, Xiangnan,Li, Cheng,Yin, Bing,Li, Cong,Liu, Ping,Li, Jianli,Shi, Zhen
supporting information, p. 1408 - 1411 (2013/07/26)
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.
