3-芳硫基-4-羟基香豆素及其类似物的制备

4-羟基香豆素类化合物与4-羟基喹啉酮类化合物是一类重要的有机杂环化合物,因为其良好的生理活性,被广泛应用于抗菌、抗炎、抗HIV、抗肿瘤等药物结构中。 本文用4-羟基香豆素类化合物或4-羟基喹啉酮类化合物作为底物、以硫磺粉(S)为硫源、以碘苯类衍生物作为芳基源,在氯化铜催化作用下合成了3-芳硫基-4-羟基香豆素类化合物和3-芳硫基-4-羟基喹啉酮类化合物。 该方法使用环境友好的硫磺粉为硫源替代有机硫,操作简单、无污染、成本低廉,为该类化合物的绿色合成提供了新的方案。     

N—甲基—N—芳基—2—（4‘—硝基苯硫基）乙酰胺类化合物的合成

先由芳胺合成N-甲基芳胺,再由氯乙酰氯酰化后与对硝基硫酚在相转移催化条件下反应,生成2-(4＇-硝基苯硫基)乙酰芳胺.该法具有操作简便,产率高的优点.     

N-甲基-N-芳基-2-(4''''-硝基苯硫基)乙酰胺类化合物的合成

先由芳胺合成 N-甲基芳胺 ,再由氯乙酰氯酰化后与对硝基硫酚在相转移催化条件下反应 ,生成 2 -(4 -硝基苯硫基 )乙酰芳胺。该法具有操作简便 ,产率高的优点。     

芳硫基乙酸酯及其氧化产物的色谱行为(Ⅲ)──在反相高效液相色谱中的行为

芳硫基乙酸酯及其氧化产物的色谱行为（Ⅲ）──在反相高效液相色谱中的行为练鸿振,茅力,苗进,徐小青,张正（南京大学现代分析中心,化学系,南京,２１００９３）关键词芳硫基乙酸酯;芳亚磺酰基乙酸酯;芳磺酰基乙酸酯;反相高效液相色谱在现代有机合成中,含硫有机...     

N-甲基-N-芳基-2-(4＇-硝基苯硫基)乙酰胺类化合物的合成

先由芳胺合成N-甲基芳胺,再由氯乙酰氯酰化后与对硝基硫酚在相转移催化条件下反应,生成2-(4＇-硝基苯硫基)乙酰芳胺.该法具有操作简便,产率高的优点.     

α-羰基烯酮环二硫代缩醛化学(Ⅵ)——β,β-1,3-亚丙二硫基-α,β-不饱和芳酮与烯丙基Grignard试剂加成物脱水反应的研究

提出了由β,β-1,3-亚丙二硫基-α,β-不饱和芳酮类化合物(1)与苄基氯化镁及烯丙基溴化镁加成所得的醇(2)在BF_3·Et_2O催化下脱水生成共轭烯烃(3)新的合成途径,合成了13种新化合物,结构经~1H N-MR、IR、UV及元素分析等确证.并对这一新合成途径的反应机制进行了讨论.     

α-羰基烯酮环二硫代缩醛化学(XXXVI)──β,β-1,3-亚丙二流基-α,β-不饱和芳酮与Grignard试剂加成物的硅胶催化分解反应

以β，β-1，3-亚丙二硫基-α，β-不饱和芳酮2与烯丙基或等基Grfenard试剂可选择性地进行1，2-加成得醇3、4，在硅胶G的催化下，醇3、4可分解生成β，γ-不饱和芳酮5、6．并对该分解反应的机制进行了初步探讨．     

高立体、区域选择性合成(Z)-1-芳硫基-2-芳硒基烯

氢氧化铯催化下,四氢呋喃作溶剂,室温、氮气保护下,炔基硫醚与硒酚发生亲核加成反应,立体选择性合成一系列(Z)-1-芳硫基-2-芳硒基烯,收率70%～93%.反应机理为氢氧化铯与硒酚反应产生的芳硒化铯,随后对炔硫醚进行亲核加成,形成的烯基负离子水解得到产物.     

α-芳甲酰基-α-肉桂酰基烯(酮-1,4-亚丁二硫缩醛的合(英)

以乙醇钠为碱，由 ２－ （１，４－ 亚丁二硫基）亚甲基芳甲酰丙酮与芳醛的缩合反应得到标题化合物，其立体化学经１ Ｈ Ｎ Ｍ Ｒ 验证为 Ｅ－ 构型。     

2-(5-芳氧基-4-苯基-1,2,4-三唑-3-硫基)乙酰芳胺的水相合成、 晶体结构及生物活性

在无催化剂存在下, 以水为溶剂通过5-芳氧基-4-苯基-1,2,4-三唑-3-硫酮与氯乙酰芳胺的硫烷基化反应, 合成了14个未见文献报道的2-(5-芳氧基-4-苯基-1,2,4-三唑-3-硫基)乙酰芳胺. 其结构经元素分析, IR和1H NMR进行了表征, 利用单晶X射线衍射法测定了化合物5n的单晶结构. 该化合物通过分子间氢键自组装成三维网状结构的超分子. 生物活性试验表明部分化合物对小麦的根有促进作用而对所有的茎都有抑制活性.     

Solid supported palladium(0) nano/microparticle: a ligand-free efficient recyclable heterogeneous catalyst for mono- and β,β-double-Heck reaction

Solid supported palladium nano/microparticles were found to be active catalysts to perform mono- and β,β-double-Heck reactions. Different β-unsubstituted and substituted alkenes including acrylate, methacrylate, crotonate, styrene, acrylonitrile, and acrylamide were investigated successfully for mono- and β,β-double-Heck reactions with aryl iodide under milder reaction condition. One-pot β,β-double-Heck reaction of aryl iodides with α,β-unsaturated ester, amide, nitrile, and styrene derivatives were also performed under standard reaction conditions. Wide functional group tolerance, easy catalyst recovery, and recyclability up to twelve times without significant loss of catalytic activity added extra importance to the present process.     

Four-Component Borocarbonylation of Vinylarenes Enabled by Cooperative Cu/Pd Catalysis: Access to β-Boryl Ketones and β-Boryl Vinyl Esters

We report here a general four-component synthetic procedure for the preparation of β-boryl ketones and β-boryl vinyl esters. Joint catalyzed by palladium and copper catalysts, borocarbonylative reaction between vinylarenes, aryl halides/triflates, B₂Pin₂, and carbon monoxide proceed successfully. A variety of synthetically useful β-boryl ketones were synthesized in good to high yields by using aryl iodides as the substrates. It is noteworthy that when aryl triflates were applied as the starting materials, β-boryl vinyl esters were synthesized in a similar manner and with broad functional group tolerance. A rational mechanism for this reaction was also proposed.     

UTILIZTION OF THE SUZUKI COUPLING TO ENHANCE THE ANTITUBERCULOSIS ACTIVITY OF ARYL OXAZOLES

Potent antituberculosis aryl oxazoles can be made in an efficient three step process--formation of β-hydroxy amides with serine benzyl ester; cyclization to afford oxazolines; and then dehydration to give the corresponding oxazoles. Furthermore, incorporation of an appropriate aryl halide allows utilization of the Suzuki cross coupling reaction to access new chemical space and more elaborate analogs. The compounds prepared by this method were shown to possess improved activity against M. tuberculosis, extremely low toxicity toward VERO cells and, as a result, high therapeutic indexes.     

Photochemical reactions of β-aminovinyl aryl thioketones

Irradiation of β-aminovinyl aryl thioketones ( 1a-b ) afforded β-aminovinyl aryl ketones ( 2a-b ). 2H-Thiopyran derivatives ( 4a-b ) were obtained when β-aminovinyl phenyl thioketone ( 1a ) was irradiated with methyl acrylate and acrylonitrile. 4H-Thiopyran derivatives ( 6,8 ) were also obtained thermally in the reaction of β-aminovinyl phenyl thioketone ( 1a ) and methyl propiolate and maleic anhydride.     

An efficient synthesis of α-aryl β-(N-tosyl)amino phosphonate derivatives from α-diazophosphonate

The α-diazophosphonate was added to aryl (N-tosyl)imine to give β-aryl β-(N-tosyl)amino α-diazophosphonates, which were further subjected to TsOH-catalyzed diazo decomposition to yield α-aryl β-(N-tosyl)enaminophosphonates through 1,2 aryl migration. The α-aryl β-(N-tosyl)enamino phosphonates were hydrogenated to give α-aryl β-(N-tosyl)amino phosphonates.     

无溶剂条件下煤基活性炭负载硫酸作为固体酸催化合成 14-烷基(芳基)-14H-二苯并[a,j]氧杂蒽类化合物

以自制的煤基活性炭负载硫酸为催化剂, β-萘酚、醛和脂肪醛为原料, 用一锅法成功合成了11个14-烷基(芳基)-14H-二苯并[a,j]氧杂蒽类化合物, 反应时间0.1～1 h, 收率71%～96%. 该方法不仅反应时间短, 产率高, 而且催化剂价廉易得, 对环境友好, 可重复利用5次, 活性没有明显降低, 并测得催化剂的酸值为3.06 mmol/g.     

Palladium-catalyzed redox cascade for direct β-arylation of ketones

Herein we report a full article about the detailed design and development of two palladium-catalyzed redox cascade methods that enable direct β-arylation of ketones. Palladium-catalyzed ketone dehydrogenation, aryl-X bond activation and conjugate addition were merged into a redox-neutral catalytic cycle. Non-metal-based aryl electrophiles were used as both the oxidant and the aryl source. The β-arylation with aryl iodides was achieved site-selectively with Pd(TFA)₂/P(i-Pr)₃ as the precatalyst and AgTFA as the iodide scavenger. Both cyclic and linear ketones can react to give β-aryl ketones with excellent functional group tolerance. The β-arylation with diaryliodonium salts was realized without stoichiometric heavy metal additives, and proved to be redox-neutral. A wider substrate scope regarding aryl groups and ketones was obtained for the arylation with diaryliodonium salts, and the possible involvement of palladium nanoparticles as the active catalyst was examined and discussed.     

Highly enantioselective synthesis of anti aryl β-hydroxy α-amino esters via DKR transfer hydrogenation

An efficient preparation of highly enantiomerically enriched aryl β-hydroxy α-amino esters via dynamic kinetic resolution (DKR), asymmetric transfer hydrogenation of α-amino β-keto esters is described. The anti β-hydroxyl α-amino esters were obtained both in high yields and high diasteroselectivity. The observed high anti selectivity is inconsistent with the previous results in literature. The absolute stereochemistry of the aryl β-hydroxy α-amino esters was unambiguously confirmed via chemical derivatization as well as Vibrational Circular Dichroism (VCD) techniques.     

Heck reactions of 2-substituted enol ethers with aryl bromides catalysed by a tetraphosphine/palladium complex

cis,cis,cis-1,2,3,4-Tetrakis(diphenylphosphinomethyl)cyclopentane/[PdCl(C₃H₅)]₂ efficiently catalyses the Heck reaction of β-substituted enol ethers with aryl bromides. Employing β-methoxystyrene, 3-ethoxyacrylonitrile or methyl 3-methoxyacrylate, the regioselective α-arylation of these enol ethers was observed in all cases, and mixtures of Z and E isomers were generally obtained, which in many cases yielded a single ketone product after acid treatment. The stereoselectivity of this reaction depends on steric and electronic factors, and better stereoselectivities in favour of Z isomers were observed with electron-rich or sterically congested aryl bromides. Better yields were obtained for this reaction with electron-rich or sterically congested aryl bromides than with electron-poor aryl bromides. This observation suggests that with these β-substituted enol ethers the rate-limiting step of the catalytic cycle is not the oxidative addition of the aryl bromide to the palladium complex.     

An efficient one-step chemoselective reduction of alkyl ketones over aryl ketones in β-diketones using LiHMDS and lithium aluminium hydride

β-Hydroxy ketones were synthesized in one-pot from β-diketones by reducing alkyl ketones chemoselectively by keeping aryl ketone intact. Initially, β-diketones were enolized using LiHMDS and later alkyl ketone was chemoselectively reduced efficiently by lithium aluminium hydride. This method produces β- hydroxyl ketones from the corresponding β-diketones in high yield.