共查询到19条相似文献,搜索用时 78 毫秒
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微波辐射和加热条件下的无催化剂无溶剂Knoevenagel缩合反应 总被引:12,自引:0,他引:12
芳香醛和丙二腈在无催化剂无溶剂存在下在微波辐射或加热条件下可以发生Knoevenagel缩合反应,反应产率良好. 相似文献
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发展了一种合成3,3-二氟-2-氧化吲哚及其衍生物的新方法。 以简单的芳香胺和溴二氟乙酸乙酯为起始原料,在无溶剂和N2气保护下搅拌5 h,得到含二氟的氮乙酰苯胺衍生物中间体,产率85%~93%。 该中间体与碘甲烷反应,得到N-甲基保护的乙酰苯胺衍生物,产率75%~90%。 该衍生物在3.0化学计量促进剂次硫酸氢钠甲醛的存在下,以N,N-二甲基甲酰胺/H2O为溶剂,发生分子内自由基关环反应,得到3,3-二氟-2-氧化吲哚及其衍生物,产率53%~72%。 该方法原料便宜,不使用任何金属化合物,最后一步以水相为溶剂,较为环保,具有潜在的工业应用价值。 相似文献
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为了发展有效合成α-腺嘌呤阿拉伯糖苷的方法,以1,2,3,5-四-O-乙酰基-β-D-阿拉伯糖和6-氯嘌呤为原料,在微波辐射和无溶剂、无催化剂条件下反应得到中间体9-α-D-(2',3',5'-三-O-乙酰基)阿拉伯呋喃糖基-6-氯嘌呤,收率85%。 该中间体物在Na2CO3催化下脱除乙酰基,然后“一锅”加入饱和的NH3/CH3OH溶液氨解,以90%的收率得到α-腺嘌呤阿拉伯糖苷。 关键中间体9-α-D-(2',3',5'-三-O-乙酰基)阿拉伯呋喃糖基-6-氯嘌呤的合成反应规模可以扩大到100 g。 类似地合成α-2-氟腺嘌呤阿拉伯糖苷和α-2-氨基腺嘌呤阿拉伯糖苷。 相似文献
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以20 mol%Et3N作为催化剂,3-羟基氧化吲哚与β-芳基丙烯二腈为原料,经Michael加成/环化串联反应合成了13个新型螺[二氢呋喃-2,3′-氧化吲哚]衍生物(3a~3m),分离收率51%~99%, dr值1:1~4:1,产物结构经1H NMR, 13C NMR和HR-MS(ESI-TOF)表征。考察了化合物对LPS激活巨噬细胞RAW264.7的抑制作用。结果表明:化合物3g的细胞抑制活性最强(IC50: 18.59 μM),化合物3d对炎症因子NO释放的抑制活性最强(IC50: 50.87 μM)。 相似文献
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Greice Tabarelli Marcelo Godoi Rômulo F. S. Canto José R. Mora Faruk Nome 《合成通讯》2014,44(23):3441-3449
We present herein a new catalyst-free and solvent-free approach for the synthesis of allylic thioethers directly from allylic alcohols and thiols. The methodology allows the synthesis of different allylic thioethers in good to excellent yields under microwave irradiation. Theoretical calculations for the allylic carbocation helped to explain the regioselectivity observed when nonsymmetric substrates are used in the reaction. 相似文献
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A green and efficient method for the synthesis of 2,4,5-triarylimidazoles by one-step condensation reaction of benzil, aromatic aldehyde, and ammonium acetate under catalyst-free, solvent-free, and microwave-irradiation conditions is reported. This method had many dramatic advantages, such as the short reaction time (3–5 min), good yields (80–99%), environmental friendliness, and convenient operation. 相似文献
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A highly efficient method for the synthesis of 1,4-phenylenedithioureas promoted by microwave irridiation is reported. It is based on the nucleophilic addition reaction of 1,4-phenylenediisothiocyanate to aromatic amines under solvent- and catalyst-free conditions. The reaction has the advantages of short reaction time, good yields, and environmental acceptability. 相似文献
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Thanasekaran Ponpandian 《合成通讯》2014,44(6):868-874
The synthesis of biologically valuable spirooxindoles and 4H-pyrans is described under catalyst-free conditions through sequential Knoevenagel–Michael–cyclization reactions from isatin or aromatic aldehyde, malononitrile, and 1,3-dicarbonyl compounds. The reaction conditions are very simple, providing excellent yield.
[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
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Solvent-free oxidative synthesis of benzimidazoles from arylmethylamines and o-phenylenediamine has been achieved under catalyst-free conditions. This reaction can use tert-butyl hydroperoxide (TBHP) as the oxidant, and a wide variety of derivatives were obtained in good yields. The reaction mechanism was proposed and this method provides a direct and practical approach for the preparation of substituted benzimidazoles. 相似文献
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A one-pot, three-component, Mannich condensation of electron-rich aromatic compounds such as 5-methyl-2-hydroxyphenyl sulfide, 2-aminopyrimidine, and various aromatic aldehydes were used to prepare a series of new unsymmetrical multidentate aminophenol ligands. These compounds were synthesized in solvent-free conditions as a fast, simple, convenient, and uncatalyzed method. Details of the reaction conditions are discussed. 相似文献
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A green and efficient procedure for the synthesis of quinoxalines is reported starting from benzil and 1,2-diaminobenzene. The reactions were carried out under catalyst-free, solvent-free, and microwave-irradiation conditions, affording the corresponding quinoxalines. This method had many dramatic advantages, such as the short reaction time (2–6 min), high yields (71–98%), and environmental friendliness, as well as convenient operation. 相似文献
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Sara Sobhani Soodabeh Rezazadeh 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2076-2084
A new and convenient procedure has been developed for the Michael addition reaction of thioacetic acid (AcSH) to a variety of conjugated alkenes under solvent- and catalyst-free conditions. These reactions proceeded in 5–60 min and produced the desired products in good to high yields. 相似文献