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1.
A new diphenylphosphinite ionic liquid (IL-OPPh2) is introduced. This ionic liquid is used as both a reagent and a solvent to convert alcohols and trimethylsilyl and tetrahydropyranyl (THP) ethers into their corresponding alkyl bromides, thiocyanates or isothiocyanates in the presence of Br2 and SCN− at 80 °C. In this ionic liquid, bromination and thiocyanation of alcohols occurs highly selectively in the presence of trimethylsilyl and THP-ethers and also between different classes of alcohols. The use of this ionic liquid allows easy separation of the desired products from the phosphinate by-product. 相似文献
2.
M. Anil Kumar K. R. Kishore Kumar Reddy M. Veeranarayana Reddy C. Devendranath Reddy 《合成通讯》2013,43(13):2089-2095
An efficient and direct approach for the α-thiocyanation of ketones with α-hydrogens has been developed using ammonium thiocyanate as a thiocyanating agent and oxone as an oxidant in methanol. 相似文献
3.
A concise, two-step eco-friendly approach towards the synthesis of 5-sulfenyl tetrazole derivatives of indoles and pyrroles, is reported. The synthesis comprises the oxone-mediated thiocyanation of the starting heterocycles towards intermediate 3-thiocyanato indoles and 2-thiocyanato pyrroles, and their subsequent treatment with sodium azide in 2-propanol/water under zinc bromide promotion. 相似文献
4.
Dr. Jingjing Wu Dr. Chao Shu Zhihang Li Dr. Adam Noble Prof. Dr. Varinder K. Aggarwal 《Angewandte Chemie (International ed. in English)》2023,62(38):e202309684
Decarboxylative halogenation reactions of alkyl carboxylic acids are highly valuable reactions for the synthesis of structurally diverse alkyl halides. However, many reported protocols rely on stoichiometric strong oxidants or highly electrophilic halogenating agents. Herein, we describe visible-light photoredox-catalyzed decarboxylative halogenation reactions of N-hydroxyphthalimide-activated carboxylic acids that avoid stoichiometric oxidants and use inexpensive inorganic halide salts as the halogenating agents. Bromination with lithium bromide proceeds under simple, transition-metal-free conditions using an organic photoredox catalyst and no other additives, whereas dual photoredox-copper catalysis is required for chlorination with lithium chloride. The mild conditions display excellent functional-group tolerance, which is demonstrated through the transformation of a diverse range of structurally complex carboxylic acid containing natural products into the corresponding alkyl bromides and chlorides. In addition, we show the generality of the dual photoredox-copper-catalyzed decarboxylative functionalization with inorganic salts by extension to thiocyanation with potassium thiocyanide, which was applied to the synthesis of complex alkyl thiocyanates. 相似文献
5.
Ardeshir Khazaei Mohammad Ali Zolfigol Mohmmad Mokhlesi Fateme Derakhshan Panah Sami Sajjadifar 《Helvetica chimica acta》2012,95(1):106-114
Two simple, mild, and efficient procedures for the thiocyanation of N‐heterocycles, substituted anilines (electron‐rich and electron‐deficient), and N‐substituted aromatic amines at room temperature are reported (Table 3). The first uses H2O2 as pollution‐free oxidant and the second H5IO6; both with the reagent potassium thiocyanate in H2O as solvent. These procedures provided the target thiocyanates after a short reaction time in good to excellent yields and high regioselectivity. 相似文献
6.
A visible-light-mediated metal-free thiocyanate radical addition/ipso-cyclization/oxidation cascade reaction for the synthesis of thiocyanato-containing azaspirotrienediones from N-phenylpropynamides is described. Cheap and readily available ammonium thiocyanate was used as a precursor to the thiocyanate free radical, which undergoes a radical addition reaction with the alkyne, followed by selective ipso-cyclization and oxidation to afford the dearomatized products. No product of ortho-cyclization was detected. The reaction completes the synthesis of C–S, C–C, and CO bonds in one pot, with abundant and renewable air oxygen as the sole sacrificial reagent and oxygen source. 相似文献
7.
A combination of triphenylphosphine (PPh3) and 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) provides a safe and easily available mixed reagent system for the conversion of 1° and 2° alcohols, thiols, trimethylsilyl-, and tetrahydropyranyl ethers to their corresponding thiocyanates and the 3° ones to isothiocyanates in good to high yields. 相似文献
8.
Mohammad Ali R. Banihashemi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):1378-1390
9.
Ricaurte Rodríguez Patricia CamargoCésar A. Sierra Carlos Y. SotoJusto Cobo Manuel Nogueras 《Tetrahedron letters》2011,52(21):2652-2654
A new, safe, and efficient methodology for the thiocyanation of some aminopyrimidine derivatives has been implemented. The thiocyanation reactions proceeded at room temperature with high yields and selectivity. This route is a less toxic alternative to other common thiocyanation techniques because it uses molecular iodine as a halogen source, which is less reactive and easier to handle than chlorine or bromine. 相似文献
10.
《Tetrahedron》2019,75(22):3053-3061
A visible-light induced metal-free thiocyanate radical addition/intramolecular cyclization cascade reaction for the synthesis of thiocyanato-containing isoquinolinediones from N-alkyl-N-methacryloylbenzamides is described. The organic dye 9-mesityl-10-methylacridinium perchlorate (Acr+-Mes ClO4−) is used as a photocatalyst, and cheap and readily available ammonium thiocyanate is used to provide thiocyanate radical by single-electron transfer pathway. The reaction completes the synthesis of CS and CC bonds in one pot with abundant molecular oxygen as the sole sacrificial reagent. The method is easy to implement, and 25 new compounds have been prepared in moderate to good yields under mild conditions. This is the first time that a thiocyanate group has been introduced into isoquinoline-1,3(2H,4H)-diones to construct highly functional drug-like molecules. 相似文献