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钐试剂在有机合成中应用的若干新进展 总被引:1,自引:0,他引:1
综述了本课题组最近几年关于钐试剂在有机合成中应用的研究进展. 主要包括以下几部分内容: (1) 二碘化钐促进的有机反应研究; (2) 金属钐直接应用于有机合成的研究; (3) 其它钐试剂 (三碘化钐, 烯丙基溴化钐) 促进的有机反应研究. 相似文献
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N,N'-二取代一硫代草酰胺的合成及其与二元胺反应的研究陆忠娥,邹建平,袁于人,陈克潜(苏州大学化学系,苏州,215006)关键词N,N'-二取代一硫代草酰胺,咪唑啉,四氢嘧啶N,N'-二硫代草酰胺可与多种金属络合,而N,N'-二取代一硫代草酰胺的合... 相似文献
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以N,N'-二芳基二硫代草酰胺与1,2-二溴乙烷进行S烷基化反应,合成了一系列2,3-双芳基亚氨基-1,4-二硫杂环己烷,反应在4h内完成,产率52%~62%.产物结构经元素分析,IR,1HNMR及MS表征,并以单晶X射线衍射分析进一步确证. 相似文献
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在SmI_2-HMPA-THF-t-BuOH体系中,硫代碳酸酯的酰硫键发生还原断裂反应,得到相应的二硫醚产物。 相似文献
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Sm(ClO4)3与N,N‘—二安替比林—1,6—己二酰胺(BAPHDCA)配合行为的相平衡 总被引:2,自引:0,他引:2
Sm(ClO4)3与N,N┐二安替比林┐1,6┐己二酰胺(BAPHDCA)配合行为的相平衡崔斌*唐宗薰张逢星郭志箴(西北大学化学系西安710069)关键词二安替比林-己二酰胺,高氯酸钐,相平衡,三元体系1997-08-06收稿,1998-01-05... 相似文献
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二碘化钐作为易得的路易斯酸型预催化剂,可有效催化芳胺和碳二亚胺的反应,在温和条件下以高收率得到一系列胍。 相似文献
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Chernov'yants MS Khohlov EV Bondarenko GI Burykin IV 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,81(1):640-644
The charge-transfer complexes (CTC) of few thioamide: 1-methylimidazoline-2-thione (MMI), 3-methyl-1-ethoxycarbonilimidazoline-2-thione (Carb), 5-methylbenzimidazoline-2-thione (BIZ), benzothiazoline-2-thione (BTZ), benzoxazoline-2-thione (BOZ) as σ-donors and diiodine as σ-acceptor were studied by spectroscopic methods (UV/Vis, (1)H NMR). CTC formation constants of thioamides with diiodine were determined using the function of the average-iodine number. The charge-transfer complexes of thioamides as π-donors with tetracyanoethylene (TCNE) as π-electron acceptor, were studied by UV-spectroscopy in dichloromethane and chloroform solutions. The mechanism of interaction MMI and Carb with TCNE have been studied by EPR spectroscopy. Spectral characteristics and formation constants are discussed in the terms of electron donor affinity of thioamides and the nature of the organic solvent used. The ionization potentials of donors were estimated from the CT transition energies of their complexes. The photolytic equilibrium constants of five thioamides are determined using pH-metric titrations. 相似文献
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Jing Du Shi-Yi Zhao Zhi-Chao Hu Jun-Xia Yu Zhi-Bing Dong 《European journal of organic chemistry》2023,26(35):e202300717
A copper-catalyzed efficient synthesis of alkynyl thioamides starting from tetraalkyl thiuram compounds (TMTM: tetramethyl thiuram monosulfide, TIBTM: tetraisobutyl thiuram monosulfide) and alkynes was reported. Thus, tetraalkyl thiurams reacted with alkynes smoothly, giving a variety of alkynyl thioamides promoted by CuI/Cs2CO3 system. This protocol features easy operation, inexpensive starting materials and good yields, illustrating its potential synthetic value for the synthesis of thioamides and their derivatives. 相似文献
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Bin Rong Lei Ding Hailei Yu Qin Yang Xuliang Liu Dongfang Xu Guisheng Li Baoguo Zhao 《Tetrahedron letters》2013
This work describes the first Pd-catalyzed allylic alkylation of thioamides. Various thioamides were efficiently α-allylated in high yields and with excellent selectivity for monoallylation under mild reaction conditions. The process not only provides a facile method for the synthesis of functionalized thioamides, but also presents a useful transformation for synthetically important thioamides. 相似文献
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A facile and direct synthetic method was developed for the construction of fully substituted dihydrothiophenes, which via a copper-catalyzed Michael addition/intramolecular cyclization/protonation cascade reaction of readily available thioamides with enynones under air atmosphere. This approach provides 2,3-dihydrothiophenes with up to 92% yield in a one-pot process. In addition, several fully substituted thiophenes could also be synthesized by changing the substituents of thioamides. 相似文献
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Zelong Wang Silin Chen Prof. Dr. Chao Chen Dr. Yunhui Yang Prof. Dr. Congyang Wang 《Angewandte Chemie (International ed. in English)》2023,62(6):e202215963
Earth-abundant transition metal catalysis has emerged as an important alternative to noble transition metal catalysis in hydrogenation reactions. However, there has been no Earth-abundant transition metal catalyzed hydrogenation of thioamides reported so far, presumably due to the poisoning of catalysts by sulfur-containing molecules. Herein, we described the first manganese-catalyzed hydrogenative desulfurization of thioamides to amines or imines. The key to success is the use of MnBr(CO)5 instead of commonly-employed pincer-manganese catalysts, together with simple NEt3 and CuBr. This protocol features excellent selectivity on sole cleavage of the C=S bond of thioamides, in contrast to the only known Ru-catalyzed hydrogenation of thioamides, and unprecedented chemo-selectivity tolerating vulnerable functional groups such as nitrile, ketone, aldehyde, ester, sulfone, nitro, olefin, alkyne and heterocycle, which are usually susceptible to common hydride-type reductive protocols. 相似文献
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Wei Min ZHU Zhi Fang LI Yong Min ZHANG 《中国化学快报》2006,17(1):1-4
Since 1977 samarium diiodide has been widely used to promote a lot of reductive and coupling reactions1. Utilizing the samarium/samarium diiodide mixed reagent, Ogawa performed the intermolecular reductive deoxygenative coupling of amides2. Our group has … 相似文献
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The methyl rotational barriers for a series of N-methyl-substituted amides and thioamides have been calculated at the MP2/6-311+G** level. A comparison of the N-methylformamide and methyl formate barriers indicates that the H [bond] C(Me) [bond] N [bond] H eclipsed torsional arrangement destabilizes an amide by about 0.8 kcal/mol. A comparison of thioamides and amides showed the importance of steric repulsion between the sulfur and a methyl hydrogen in the Z-forms of the thioamides. The C [bond] N bond rotation transition states of the N,N-dimethyl amides have much larger methyl rotational barriers than found in the ground states. They can be attributed to the smaller CH(3)(-)N [bond] CH(3) bond angles in the transition states. 相似文献
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Arpal Pal Naga D. Koduri Zhiguo Wang Erika Lopez Quiroz Alexandra Chong Matthew Vuong Nisha Rajagopal Michael Nguyen Kenneth P. Roberts Syed R. Hussaini 《Tetrahedron letters》2017,58(6):586-589
The development of operationally simple and cost-effective methods for CC bond formation reactions are highly important in pharmaceutical, agrochemical and material research. In this article we describe the first copper-catalyzed cross-coupling reaction of thioamides with acceptor/acceptor-substituted and acceptor-only substituted α-diazocarbonyl compounds to yield enaminones. The reaction shows broad substrate scope in terms of thioamides and diazocarbonyl compounds. Primary, secondary and tertiary thioamides all give enanminones when reacted with α-diazodiesters, α-diazoketoesters, α-diazodiketones, α-diazoketoamides, α-diazoesteramides, α-diazoketosulfones and α-diazomonoketones. 相似文献
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Summary. Several enantiomerically pure 3,5-disubstituted isothiazol-5-ylideneamine hydrobromides were prepared by oxidation of chiral
3-amino-2,3-unsaturated thioamides. The starting thioamides derived from natural L-α-amino acids represent a novel group of synthetically useful chiral reactants. 相似文献
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Alexander B. Rozhenko Sergiy S. Mykhaylychenko Nadiya V. Pikun Yuriy G. Shermolovich Jerzy Leszczynski 《International journal of quantum chemistry》2014,114(4):241-248
The reactions of perfluoroalkyl thioamides with trimethyl phosphine, trimethyl phosphite, and tris(dimethylamino)phosphine have been analyzed by means of quantum chemical (DFT and MP2) calculations. The reaction seems to proceed via the nucleophilic attack of the electrophilic carbon atom by the phosphorus lone pair with the formation of cyclic or acyclic adducts. The latter releases the thiophosphate molecule forming perfluoroalkylaminocarbene as the short‐lived intermediate. The reaction of the carbene with the second molecule of trialkyl phosphite yields phosphorus ylide. The ylide undergoes a migration of fluorine from carbon to phosphorus. The reactions of perfluoroalkyl thioamides with phosphines and tris(dimethylamino)phosphine probably proceeds differently. Using alkyl thioamides or amides instead of perfluoroalkyl thioamides also makes the reaction less favorable. The only combination of perfluoroalkyl thioamides with trialkyl phosphite fulfills both the kinetic requirements (moderate activation energies and relative energies for intermediates) and the thermodynamic aspects (higher stabilities of the reaction products compared with the starting materials). © 2013 Wiley Periodicals, Inc. 相似文献