共查询到20条相似文献,搜索用时 15 毫秒
1.
Benjamin D. Reeves Jonathan K. HilmerLisa Mellmann Myra HartzheimKevin Poffenberger Keith JohnsonNeelambari Joshi David J. SingelPaul A. Grieco 《Tetrahedron letters》2013
The conversion of S-nitrosothiols to thiosulfonates by reaction with the sodium salt of benzenesulfinic acid (PhSO2Na) has been examined in detail with the exemplary substrates S-nitrosoglutathione (GSNO) and S-nitrosylated bovine serum albumin (SNO-BSA). The reaction stoichiometry (2:1, PhSO2Na:RSNO) and the rate law (first order in both PhSO2Na and RSNO) have been determined under mild acidic conditions (pH 4.0). The products have been identified as the corresponding thiosulfonates (GSSO2Ph and BSA-SSO2Ph) along with PhSO2NHOH obtained in a 1:1 ratio. GSH, GSSG, and BSA were unreactive to PhSO2Na. 相似文献
2.
Visible light induced decomposition of sulfonyl hydrazides using Pd/ZrO2 nanocomposite photocatalyst
A new approach to synthesis of thiosulfonates has been developed under mild conditions without any oxidants and promoting reagents through a Pd/ZrO2 nanocomposite photocatalyst catalyzed decomposition of sulfonyl hydrazides. This protocol gave the products in moderate yields, comparable to the best results reported so far. Finally, a plausible reaction mechanism was proposed. 相似文献
3.
Satish R. Lanke 《合成通讯》2014,44(3):399-407
This work reports an efficient protocol for the coupling reaction of aryl iodides/boronic acids with sodium azide to aryl azides/amines in the presence of copper bis(2,2,6,6-tetramethyl-3,5-heptanedionate) Cu(TMHD)2 catalyst. The Cu(TMHD)2 catalyst is a structurally well-defined, O-containing, air- and moisture-stable, transition-metal complex and works at mild reaction conditions. It was observed that aryl azides can be reduced further to corresponding aniline derivatives using the same catalyst under basic reaction conditions for a prolonged period.
[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.] 相似文献
4.
Amino acids are firstly employed in transition-metal free heterocyclization reaction of 1,3-diynes in the presence of K3PO4 and DMSO at 120 °C. This method produces 2,3,6-trisubstituted pyridines with up to 86% yield. The –CO2H group on the amino acids is crucial for this heterocyclization reaction. The mechanism of such a heterocyclization reaction is discussed, as well. 相似文献
5.
Jiaqi Ma Chao Hong Yan Wan Meichao Li Xinquan Hu Weimin Mo Baoxiang Hu Nan Sun Liqun Jin Zhenlu Shen 《Tetrahedron letters》2017,58(7):652-657
A green and efficient transition-metal free ABNO/tert-butyl nitrite/KPF6-catalyzed aerobic oxidation of secondary alcohols in water has been achieved. Under the optimal reaction conditions, a number of secondary aliphatic alcohols and secondary benzylic alcohols can be converted to their corresponding ketones in excellent yields (up to 99%). 相似文献
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7.
Alexander Kremsmair Henrik R. Wilke Matthias M. Simon Quirin Schmidt Konstantin Karaghiosoff Paul Knochel 《Chemical science》2021,13(1):44
A general preparation of enantiomerically and diastereomerically enriched secondary alkylmagnesium reagents was reported as well as their use for performing highly stereoselective transition-metal free electrophilic aminations leading to α-chiral amines in up to 97% ee. Thus, the reaction of t-BuLi (2.2 equiv.) with a mixture of chiral secondary alkyl iodides and the commercially available magnesium reagent Me3SiCH2MgCl in a 2 : 1 mixture of pentane and diethyl ether at up to −50 °C provided optically enriched secondary mixed alkylmagnesium species of the type alkyl(Me)CHMgCH2SiMe3 with high retention of configuration (up to 99% ee). The resulting enantiomerically enriched dialkylmagnesium reagents were trapped with electrophiles such as non-enolizable ketones, aldehydes, acid chlorides, isocyanates, chlorophosphines and O-benzoyl hydroxylamines providing α-chiral tertiary alcohols, ketones, amides, phosphines and tertiary amines in up to 89% yield (over three reaction steps) and up to 99% ee.We report a general method for the preparation of enantiomerically enriched secondary alkylmagnesium reagents, which undergo highly stereoselective transition-metal free electrophilic aminations, leading to α-chiral amines in up to 97% ee. 相似文献
8.
Masayuki Kirihara Sayuri NaitoYuki Nishimura Yuki IshizukaToshiaki Iwai Haruka TakeuchiTomomi Ogata Honoka HanaiYukari Kinoshita Mari KishidaKento Yamazaki Takuya NoguchiShiro Yamashoji 《Tetrahedron》2014
The reaction of aromatic or benzylic disulfides with 2.5 equiv of Selectfluor™ in acetonitrile/water (10:1) at room temperature efficiently produced the corresponding thiosulfonates. Conversely, the reaction of disulfides with 6.5 equiv of Selectfluor™ or thiosulfonates with 4.5 equiv of Selectfluor™ in refluxing acetonitrile/water (10:1) provided sulfonyl fluorides in high yields. Accufluor™ and FP-T300™ are also effective in preparing sulfonyl fluorides from disulfides under the similar reaction conditions. Sulfonyl chlorides or sulfonyl bromides were effectively obtained from the reaction of disulfides with 6 equiv of either N-chlorosuccinimide or N-bromosuccinimide in acetonitrile/water (10:1) at room temperature. Some other electrophilic chlorinating or brominating reagents are also able to be used instead of N-chlorosuccinimide or N-bromosuccinimide for the syntheses of sulfonyl halides from disulfides. These reactions of disulfides with electrophilic halogenating reagents are convenient methods to prepare thiosulfonates and sulfonyl halides. 相似文献
9.
Olga M. Lezina Svetlana N. Subbotina Larisa L. Frolova Svetlana A. Rubtsova Denis V. Sudarikov 《Molecules (Basel, Switzerland)》2021,26(17)
Chiral γ-ketothiols, thioacetates, thiobenzoate, disulfides, sulfones, thiosulfonates, and sulfonic acids were obtained from β-pinene for the first time. New compounds open up prospects for the synthesis of other polyfunctional compounds combining a biologically active pinane fragment with various pharmacophore groups. It was shown that the syntheses of sulfanyl and sulfonyl derivatives based on 2-norpinanone are characterized by high stereoselectivity in comparison with similar reactions of pinocarvone. The conditions for the preparation of diastereomerically pure thioacetyl and thiobenzoyl derivatives based on pinocarvone, as well as for the chemoselective oxidation of γ-ketothiols with chlorine dioxide to the corresponding thiolsulfonates and sulfonic acids, were selected. The effect of the VO(acac)2 catalyst on the increase in the yields of thiosulfonates was shown. A new direction of the transformation of thiosulfonates with the formation of sulfones was revealed. In the case of pinocarvone-based sulfones, the configuration is inversed at the C2 atom. An epimerization scheme is proposed. 相似文献
10.
《中国化学快报》2021,32(12):4033-4037
A visible-light-induced chemoselective reactions of quinoxalin-2(1H)-ones with alkylboronic acids in the presence of air (O2) and N2 atmosphere was developed under transition-metal free conditions, providing 3-alkylquinoxalin-2(1H)-ones and 3,4-dihydroquinoxalin-2(1H)-ones, respectively. The overall strategy accommodates a broad scope of substituted quinoxalin-2(1H)-ones and alkylboronic acids with good to excellent product yields. 相似文献
11.
A method for the facile synthesis of tetraaryl-trimethylsilylmethyl-hydro[60]fullerenes, C60Ar4(CH2SiMeR)H, has been developed in which readily prepared anionic mono(silylmethyl) fullerene is subjected to reaction conditions for organocopper-mediated multiple addition. Penta(organo)fullerene derivatives bearing different substituents and diverse functionality were synthesized in moderate to good yield under simple and mild reaction conditions. Further organic and organometallic transformations of these fullerenes allowed us to synthesize transition-metal complexes and a new methanofullerene derivative, 1,9-methano-6,12,15,18-tetraphenyl[60]fullerene, C60Ph4(CH2). 相似文献
12.
Fillmore Freeman Lisa G. Bartosik Nghe Van Bui Monica C. Keindl Eric L. Nelson 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3-4):375-386
Abstract Arenesulfinyl chlorides (4-XC6H4S(O)Cl); × = H, CH3, F, Cl, Br) react with activated zerovalent zinc in benzene at 6 to 8°C to give symmetrical S-aryl arenesulfonothioates (thiosulfonates) in good to excellent yields. 2-and 3-Substituted arenesulfinyl chlorides (X = Cl, CH3) give a mixture of products (disulfide, thiosulfinate, and/or thiosulfonate). 2,4,6-Triisopropylbenzenesulfinyl chloride reacts with zinc in 1,2-dimethoxyethane to give S-(2,4,6-triisopropylphenyl) 2,4,6-triisopropylbenzenesulfinothioate and bis(2,4,6-triisopropylphenyl) disulfide. Possible mechanisms for the reactions, the 1H and 13C NMR spectra, and the chemical ionization and electron impact mass spectra of the thiosulfonates are discussed. The para carbon substituent chemical shifts (Cp-SCS) for the thiosulfonates and for symmetrical diaryl disulfides have been subjected to several dual substituent parameter (DSP) correlations. 相似文献
13.
以水为反应介质,水合肼为还原剂,研究了痕量铜催化3-甲基蒽醌-[1,2-c]-异噁唑还原开环反应以清洁高效合成1-氨基-2-乙酰基蒽醌,考察了不同种类过渡金属硝酸盐的催化性能,发现Cu(NO3)2性能最好. 加入 2.6% 的催化剂和1.3倍的水合肼,在室温反应 2 h,底物转化率和目标产物选择性分别可达到 97.2%和 95%,TON达到38. 产品结构经氢核磁谱和质谱得以确证,主要副产为羟基取代的1-氨基-2-乙酰基蒽醌. 此外,提出了铜催化 3-甲基蒽醌-[1,2-c]-异噁唑还原开环反应合成 1-氨基-2-乙酰基蒽醌的可能反应机理. 相似文献
14.
The chemical ionization and electron impact mass spectra of some thiosulfinates, thiosulfonates and sulfinyl sulfones have been studied. The electron impact mass spectra of four of the six thiosulfonates show molecular ions of less than 1%. Inconclusive evidence was obtained for sulfenyl sulfinate type intermediates in the electron impact spectra of thiosulfonates. The electron impact spectra of thiosulfonates were similar to those of thiosulfonates. The chemical ionization (isobutane) mass spectra of thiosulfinates and thiosulfonates generally show protonated molecular ions [MH]+ as base peaks and [MH+1]+ and [MH+2]+ peaks. 相似文献
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16.
A polyol-mediated synthesis is presented as a general access to nanoscaled transition-metal tungstates MWO4 (M = Mn, Fe, Co, Ni, Cu, Zn). Using simple inorganic salts as starting materials, uniform and readily crystalline nanoparticles are prepared under mild conditions (T < 220 °C). The nanoparticles are of high quality in terms of small diameter (<20 nm), high surface area (up to 200 m2 g−1), phase purity and yield (>85%). Size, morphology and composition can be adjusted by precise variation of the reaction parameters, including type of starting material, duration and temperature of reaction. The transition-metal tungstate nanoparticles are fully functional, exhibiting typical properties of this class of materials, for instance, superparamagnetism (CoWO4), luminescence (ZnWO4) and photocatalytic activity (CuWO4). 相似文献
17.
Unsymmetric S-aryl thiosulfonates can be generated through a novel way for the reaction of potassium thiosulfonates with diaryliodonium salts in good yields under mild conditions. 相似文献
18.
Sarita Mishra 《合成通讯》2013,43(15):2229-2244
An efficient one-pot, multicomponent synthesis of 3,5-dicyanopyridines has been developed from the reaction of malononitrile and different thiophenol or thiols with a variety of aldehydes (aromatic including hindered ones, heteroaromatic, and aliphatic) in the presence of 20 mol% of K2CO3 in refluxing 50% aqeuous ethanol. KMnO4 has been utilized as a readily available, inexpensive oxidant for the in situ transformation of the initially formed dihydropyridine intermediate. K2CO3 also mediates the one-pot formation of chromeno[2,3-b]pyridines from reaction of salicylaldehyde or its analogs with malononitrile and thiol or thiophenols. Both of these conditions also work equally well under 50-fold scale-up conditions. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file. 相似文献
19.
Zhen Zhou Miaochang Liu Song Sun En Yao Suqin Liu Zhiwen Wu Jin-Tao Yu Yan Jiang Jiang Cheng 《Tetrahedron letters》2017,58(26):2571-2573
A base-promoted three-component reaction between arylmethyl bromides, arylamidines and elemental sulfur was developed, leading to unsymmetric 3,5-diaryl-1,2,4-thiadiazoles in moderate to good yields with chemical diversity and complexity. This procedure shows broad substrates scope by employing elemental sulfur and commercially available starting materials under transition-metal free conditions. 相似文献
20.
Feng Zhang Xing Liu Jian Zhou Xian-Hong Yin Jun He 《Monatshefte für Chemie / Chemical Monthly》2011,22(1):763-768