- Transition-metal-free decarboxylative thiolation of stable aliphatic carboxylates
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A transition-metal-free decarboxylative thiolation protocol is reported in which primary, secondary, tertiary (hetero)aryl acetates and α-CN substituted acetates undergo the decarboxylative thiolation smoothly, to deliver a variety of functionalized aryl alkyl sulfides in moderate to excellent yields. Aryl diselenides are also amenable substrates for construction of C-Se bonds under the simple and mild reaction conditions. Moreover, the protocol is successfully applied to the late-stage modification of pharmaceutical carboxylates with satisfactory chemoselectivity and functional-group compatibility. This journal is
- Xing, Wei-Long,Liu, De-Guang,Fu, Ming-Chen
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p. 4593 - 4597
(2021/02/03)
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- Transition metal-free coupling reactions of benzylic trimethylammonium salts with di(hetero)aryl disulfides and diselenides
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A new protocol was developed to synthesize (enantioenriched) thioethers and selenoethers from (chiral) benzylic trimethylammonium salts and di(hetero)aryl disulfides or diselenides. These syntheses were promoted by the presence of weak base and did not require the use of any transition metal, and resulted in the target products with good to excellent yields (72-94%). Using quaternary ammonium salts synthesized from enantiomerically enriched amines led to highly enantiopure benzylic thioethers and selenoethers (94-99% ee) with configurations reversed from those of their enantioenriched quaternary ammonium salts. This journal is
- Li, Fuhai,Wang, Dan,Chen, Hongyi,He, Ze,Zhou, Lihong,Zeng, Qingle
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supporting information
p. 13029 - 13032
(2020/11/07)
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- Alkyl Sulfides as Promising Sulfur Sources: Metal-Free Synthesis of Aryl Alkyl Sulfides and Dialkyl Sulfides by Transalkylation of Simple Sulfides with Alkyl Halides
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A site-selective metal-free dealkylative approach to synthesize aryl alkyl and symmetrical dialkyl sulfides has been developed. This procedure is convenient and has wide functional group tolerance giving rise to sulfides carrying various alkyl chains from simple alkyl sulfides and alkyl halides in good to excellent yields. This transalkylation proceeds by an ionic mechanism via sulfonium intermediates and it was proposed that dimethylacetamide (DMAC) may participate in part to promote the reaction.
- Liu, Ting,Qiu, Renhua,Zhu, Longzhi,Yin, Shuang-Feng,Au, Chak-Tong,Kambe, Nobuaki
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supporting information
p. 3833 - 3837
(2018/12/05)
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- An aryl alkyl thioether compound and its synthetic method
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The invention discloses a synthetic method of an aryl alkyl thioether compound shown as formula (II), and the synthetic method is as follows: at room temperature and in a water phase, using triazene and haloalkane as reaction raw materials, using Na2S2O3 as a vulcanization reagent for reaction under the promotion effect of a copper catalyst and a Lewis acid to obtain the aryl alkyl thioether compound. The advantages of the synthetic method are as follows: reaction is efficient and yield is high; the vulcanization reagent is cheap, easy to obtain, stable, and free of irritating smell; the reaction is carried out in the solvent green water, the reaction is free of addition of a phase transfer catalyst and a volatile organic solvent, and is environmentally friendly; the reaction is carried out at room temperature, is mild in condition; the catalyst copper sulfate used in the reaction is cheap and economic reaction; the reaction substrate is easy in preparation; after amplification, the reaction efficiency is higher.
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Paragraph 0182-0185
(2019/02/04)
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- Sulfide synthesis through copper-catalyzed C-S bond formation under biomolecule-compatible conditions
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We report here an efficient and mild method for constructing C-S bonds. The reactions were carried out with Na2S2O3 as a sulfurating reagent, CuSO4 as a catalyst, and water as solvent without any surfactant. The products were achieved in moderate to excellent yields at room temperature under air. Notably, this reaction is compatible with various biomolecules including amino acids, oligosaccharides, nucleosides, proteins, and cell lysates. This journal is
- Zhang, Yonghong,Li, Yiming,Zhang, Xiaomei,Jiang, Xuefeng
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p. 941 - 944
(2015/01/09)
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- Neutral sulfur nucleophiles: Synthesis of thioethers and thioesters by substitution reactions of N-heterocyclic carbene boryl sulfides and thioamides
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Newly discovered boryl sulfides and N-borylthioamides are shown to serve as neutral sources of sulfur nucleophiles in substitutions reactions. For example, heating of diMe-Imd-BH(SPh)2 with benzyl bromides, primary bromides, or acid chlorides provides the corresponding thioethers or thioesters in high yields. Likewise, N-phenyltetrazole thioethers/esters are made from a readily available N-borylthionotetrazole. The formation of the boryl sulfide and its onward nucleophilic substitution can be telescoped down to a one-pot reaction whose components are an NHC-borane (NHC-BH3), a disulfide, and an electrophile.
- Pan, Xiangcheng,Curran, Dennis P.
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supporting information
p. 2728 - 2731
(2014/06/09)
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- A novel approach to the practical synthesis of sulfides: An InBr 3-Et3SiH catalytic system promoted the direct reductive sulfidation of acetais with disulfides
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We have demonstrated a facile and direct synthesis of sulfide derivatives using acetais and ketals, derived, from aromatic/ conjugated, aldehydes and aromatic ketones, with disulfides and the InBr3-Et3SiH reducing system., We also succeeded in developing an unprecedented one-pot preparation of an aliphatic sulfide from a disulfide and an aliphatic acetal. (Wiley-VCH Verlag GmbH & Co. KGaA.
- Sakai, Norio,Moritaka, Kohei,Konakahara, Takeo
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supporting information; experimental part
p. 4123 - 4127
(2009/12/09)
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- Mild and efficient deoxygenation of sulfoxides to sulfides with triflic anhydride/potassium iodide reagent system
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It was found that the combination of triflic anhydride/potassium iodide was an effective promoter for the deoxygenation of sulfoxides and gave the corresponding sulfides in excellent yield in acetonitrile at room temperature. It is worth mentioning that this reagent system is chemoselective and tolerates various functional groups, such as alkene, ketone, ester, aldehyde, acid, and oxime. Georg Thieme Verlag Stuttgart.
- Bahrami, Kiumars,Khodaei, Mohammad Mehdi,Karimi, Ahmad
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experimental part
p. 2543 - 2546
(2009/04/04)
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- Inhibition of human O6-alkylguanine-DNA alkyltransferase and potentiation of the cytotoxicity of chloroethylnitrosourea by 4(6)- (benzyloxy)-2,6(4)-diamino-5-(nitro or nitroso)pyrimidine derivatives and analogues
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A series of 4(6)-(benzyloxy)-2,6(4)-diamino-5-(nitro or nitroso)pyrimidine derivatives and analogues of which 4(6)-benzyloxy groups were replaced with a (2-, 3-, or 4-fluorobenzyl)oxy or (2-, 3-, or 4- pyridylmethyl)oxy group, was synthesized. The abilities of these compounds to inhibit human O6-alkylguanine-DNA alkyltransferase (AGAT) in vitro and to potentiate the cytotoxicity of 1-[(4-amino-2-methyl-5-pyrimidinyl)methyl]-3- (2-chloroethyl)-3-nitrosourea (ACNU) toward HeLa S3 cells were evaluated. 2,4-Diamino-6-[(2-fluorobenzyl)oxy]-5-nitropyrimidine (3) and 2,4-diamino-5- nitro-6-(2-pyridylmethoxy)pyrimidine (6), whose ortho positions of the 6- substituent are modified, were much weaker in terms of these abilities than the corresponding meta- or para-modified compounds. These results are consistent with those of our previous study using a series of O6- benzylguanine derivatives. All 5-nitrosopyrimidine derivatives examined exerted both stronger AGAT-inhibition and ACNU-enhancement abilities than the corresponding 5-nitro derivatives. Among a variety of compounds that we have examined to date, 2,4-diamino-6-[(4-fluorobenzyl)oxy]-5-nitrosopyrimidine (10) exhibited the strongest ability to inhibit AGAT, and its magnitude was 2.5 and 50 times those of 4-(benzyloxy)-2,6-diamino-5-nitrosopyrimidine (9) and O6-benzylguanine (1), respectively. A strong positive correlation was observed between the ability to inhibit AGAT and to potentiate the cytotoxicity of ACNU. This strongly indicates that 4(6)-(benzyloxy)pyrimidine derivatives and their analogues potentiate ACNU cytotoxicity by inhibiting AGAT activity. To characterize the reactivity of test compounds, alkyl- transfer reactions were also carried out using the biomimetic alkyl-transfer system.
- Terashima, Isamu,Kohda, Kohfuku
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p. 503 - 508
(2007/10/03)
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- Potentiation of the cytotoxicity of chloroethylnitrosourea by O6-arylmethylguanines
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It was reported recently that monomeric O6-benzylguanine (1) acts as an alternative substrate for a DNA repair enzyme, O6-alkylguanine-DNA alkyltransferase (AGT), and that therefore pretreatment of cells with 1 induces depletion of AGT resulting in an enhanced cytotoxic response to alkylating antitumor agents. In order to study the interaction of O6-benzylguanine derivatives with AGT and to obtain greater AGT depletion, me synthesized the following O6-arylmethylguanine derivatives and related compounds: O6-(4-, 3- and 2-fluorobenzyl)guanines (2, 3, 4), O6-(4-,3- and 2-trifluoromethylbenzyl)guanines (5, 6, 7), O6-(4-, 3- and 2-pyridylmethyl)guanines (8, 9, 10), O6-(2- and 1-naphthylmethyl)guanines (11, 12), O6-biphenylmethylguanine (13), S and Se analogues of O6-benzylguanine (14, 15) and O6-phenylguanine (16). Ten of these are new compounds. All these compounds were tested for their potentiation of N'-[(4-amino-2-methyl-5-pyrimidinyl)methyl] (ACNU) cytotoxicity using HeLa S3 and C6-1 cells. Compounds 2, 3, 5, 8, 9, 11 and 13 were active, as was 1. Compounds 7 and 12, with a substituent at the a position of the benzyl group, and compound 10, the a-nitrogen analogue of 1, were almost completely devoid of potentiating activity. These results suggest that the a-position of the O6-benzyl group plays an important role in the interaction of O6-benzylguanines with AGT. Of the other compounds, 4 and 6 exhibited very weak activity and 14, 15 and 16 were inactive. Possible reasons for these differences in activity are discussed in relation to the biomimetic dealkylation rates of O6-benzylguanine derivatives and the chemical characteristics of their substituents.
- Kohda,Terashima,Koyama,Watanabe,Mineura
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p. 424 - 430
(2007/10/03)
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