苯过氧硒酸已被提出作为广泛使用的烯烃与苯硒酸和过氧化氢环氧化的关键中间体。然而,它与环辛烯反应缓慢,而是在溶液中迅速分解为混合的硒化硒酸硒酸盐,该盐通过X射线吸收和77 Se NMR光谱以及单晶X射线衍射鉴定。该方法包括通过释放氧气的亚硒酸消除过氧硒酸和其他氧化还原步骤。该盐在固态下相对稳定,但是在过氧化氢的存在下产生相应的亚硒酸。亚硒酸本身对环辛烯呈惰性;然而,当添加过氧化氢时,会发生快速的环氧化。这表明亚硒酸必须首先通过进一步的氧化活化,大概是迄今未知的苯过氧硒酸。后者是该环氧化反应中的主要氧化剂。
The polyhedral nature of selenium-catalysed reactions: Se(<scp>iv</scp>) species instead of Se(<scp>vi</scp>) species make the difference in the on water selenium-mediated oxidation of arylamines
Selenium-catalysed oxidations are highly sought after in organic synthesis and biology. Herein, we report our studies on the on water selenium mediated oxidation of anilines. In the presence of diphenyldiselenide or benzeneseleninic acid, anilines react with hydrogen peroxide, providing direct and selective access to nitroarenes. On the other hand, the use of selenium dioxide or sodium selenite leads
硒催化氧化在有机合成和生物学中备受追捧。在此,我们报告了我们对水硒介导的苯胺氧化的研究。在二苯基二硒化物或苯硒酸存在下,苯胺与过氧化氢反应,直接和选择性地获得硝基芳烃。另一方面,使用二氧化硒或亚硒酸钠会产生氧化偶氮芳烃。仔细的机理分析和77 Se NMR 研究表明,只有 Se( IV ) 物质,如苯过氧硒酸,是参与在水中运行并导致硝基芳烃的催化循环的活性氧化剂。虽然最近在有机溶剂中发生的其他硒催化氧化反应已被证明是通过 Se( VI) 关键中间体,苯胺在水中氧化成硝基芳烃没有。这些发现揭示了有机硒催化转化的多方面性质,并开辟了利用硒基催化的新方向。
One-Pot Synthesis of Aryl Selenonic Acids and Some Unexpected Byproducts
作者:Kai N. Sands、Benjamin S. Gelfand、Thomas G. Back
DOI:10.1021/acs.joc.1c01369
日期:2021.8.6
The synthesis of aryl selenonic acids was achieved from diverse aryl bromides via a one-pot method involving metalation, selenation, and oxidation with hydrogen peroxide followed by ion exchange to afford the pure products in 77–90% yield. An o-hydroxymethyl derivative was found to dehydrate readily, affording the first example of a cyclic selenonic ester, while two minor byproducts were isolated and
Modelling the Inhibition of Selenoproteins by Small Molecules Using Cysteine and Selenocysteine Derivatives
作者:Kishorkumar M. Reddy、Govindasamy Mugesh
DOI:10.1002/chem.201901363
日期:——
cysteine‐ and selenocysteine‐containing proteins. CDNB has been used extensively to determine the activity of glutathione S‐transferase and to deplete glutathione (GSH) in mammalian cells. Also, CDNB has been shown to irreversibly inhibit thioredoxinreductase (TrxR), a selenoenzyme that catalyses the reduction of thioredoxin (Trx). Mammalian TrxR has a C‐terminal activesite motif, Gly‐Cys‐Sec‐Gly, and
基于小分子的亲电子化合物,例如1-氯-2-,4-二硝基苯(CDNB)和1-氯-4-硝基苯(CNB)被用作半胱氨酸和硒代半胱氨酸蛋白的抑制剂。CDNB已被广泛用于确定谷胱甘肽S的活性转移酶并耗尽哺乳动物细胞中的谷胱甘肽(GSH)。而且,已证明CDNB不可逆地抑制硫氧还蛋白还原酶(TrxR),这是一种催化硫氧还蛋白(Trx)还原的硒酶。哺乳动物TrxR具有C端活性位点基序Gly-Cys-Sec-Gly,半胱氨酸和硒代半胱氨酸残基都可能是亲电子试剂的靶标。在本文中,我们报告了一系列半胱氨酸和硒代半胱氨酸衍生物的稳定性,这些衍生物可被视为硒代酶-抑制剂复合物的模型。我们证明这些衍生物与H 2 O 2反应生成相应的亚硒酸盐,将其自发消除以生成脱氢丙氨酸。相反,半胱氨酸衍生物对这种消除反应是稳定的。我们还首次证明了从硒代半胱氨酸衍生物中消除的芳基硒物种通过在GSH存在下催化H 2 O 2的还原而表现出
Benzeneperoxyseleninic acids-synthesis and properties
作者:Ludwik Syper、Jacek Młochowski
DOI:10.1016/s0040-4020(01)89946-4
日期:1987.1
Pyman, Journal of the Chemical Society, 1919, vol. 115, p. 163,165