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Multi-substituted dihydrofurans are valuable intermediates for the synthesis of natural products and pharmaceuticals. Considerable attention has been focused on the development of efficient and regioselective methods for their preparation. Using K2CO3 as a base, with the reaction of fur-2-oylmethyltriphenylarsonium bromide 1 and ethyl 2-acetyl-3-arylacrylate 2 in tetrahydrofuran at room temperature, we found an efficient protocol was achieved to synthesize trans-3-aryl-4-carbethoxy-2,3-dihydro-2-fur-2'-oyl-5-methylfurans 3 in good yield with high stereoselectivity. The structure of compound 3 was confirmed by IR, ^1H NMR, MS and HRMS. The mechanism for the formation of 3 was proposed. 相似文献
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溴化(a-噻吩甲酰基)甲基三苯鉮1与3-取代苯甲叉基-2,4-戊二酮 2以碳酸钾为碱,在苯中55℃条件下反应,可以较好的收率、高立体选择性地生成反-2-(a-噻吩甲酰基)-3-取代苯基-4-乙氧羰基-5-甲基-2,3-二氢呋喃3。产物结构均经波谱予以确定。本文还提出了生成产物的可能机理。 相似文献
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Phosphonium or arsonium salt 1 can undergo the tandem reaction of deprotonation -oxidation-Wittig reaction with alcohol 2 in the presence of sodium hydroxide and manganese dioxide,which affords a general simplified method for the stereoselective synthesis of (E)- α-β-unsaturated esters 3. 相似文献
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研究了3种合成2甲氧羰基3芳基4乙酰基5甲基顺2,3二氢呋喃(7)的方法.方法1:用甲氧羰基亚甲基三苯基胂(5)与3(取代苯甲叉)2,4戊二酮(6)反应;方法2:用溴化甲氧羰基甲基三苯基胂(4)在碳酸钾存在下与戊二酮6反应;方法3(分步一锅法):三苯基胂(2)与溴代乙酸甲酯(3)加热反应,生成的产物不经分离,冷却至室温,加入碳酸钾和6继续反应. 相似文献
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Novel β-C-disaccharides containing a three carbon linkage using exo-glycal as the precursor were prepared stereoselectively. The synthesis was achieved by the tandem reactions of the stereoselective hydroboration of exo-glycal and Suzuki cross-coupling reaction with an iodovinyl sugar, and followed by hydrogenated deprotection under the catalysis of Pd(OH)2/C. 相似文献
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An efficient method for the preparation of 1,3-dioxolanes via the coupling of epoxides with ketones catalyzed by heteropolyacids at ambient temperature has been described. 相似文献
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WeiZHANG YanPingGUO LiYANG ZhongLiLIU 《中国化学快报》2005,16(5):575-578
Photochemically promoted Diels-Alder reactions of 1, 4-diaryl-1-azabutadienes with 2,3-dihydrofuran were achieved by using 2, 4, 6-triphenylpyrylium tetrafluoroborate as catalyst to produce corresponding styrylfuroquinolines in high yield. 相似文献
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LI Wei HUANG Hai JIN Xiaodong LIU Yujian XU Chaohang ZHU Hongjun 《高等学校化学研究》2014,30(5):770-773
The authors described a short and highly enantioselective route to (R)-salmeterol involving asymmetric synthesis of cyanohydrin followed by nucleophilic substitution with 6-(4-phenylbutoxy) hexyl methanesulfonate. 相似文献
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MeiHuaXIE LuLingWU XianHUANG 《中国化学快报》2003,14(9):887-888
Phenylseleno and sulfonyl substituted allyl alcohols were synthesized stereoselectively by the three-componem reaction of acetylenic sulfone, phenylselenomagnesium bromide and ketones in one-pot. 相似文献
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A facile and highly stereoselective methodology for the preparation of highly functionalized trans-1,2-cyclopropanes containing benzoimidazolyl, cyano, aryl, and carbonyl groups 3 is described. Arsonium bromides 2 reacted with electron-deficient olefins 1 in the presence of KF·2H2O to provide 3 exclusively with high stereoselectivity in moderate to good yields. 相似文献
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为获得含氮芥和蒽环的α,β-不饱和酮衍生物及其体外抗肿瘤效果,结合Vilsmeier-Haack反应和羟醛缩合反应合成了两种新型含氮芥和蒽环的α,β-不饱和酮(1a和1b),其结构经1H NMR、13C NMR、 MS(ESI)和紫外和荧光光谱表征。采用MTT法检测了1a和1b对肺癌细胞A549、肾癌细胞786-O、宫颈癌细胞Hela和乳腺癌细胞MDA-MB-231增殖的抑制活性;采用细胞划痕实验检测了1a对Hela细胞转移的影响;采用流式细胞仪(PI染色)检测了1a对Hela细胞周期的影响。结果表明:1a和1b对4种肿瘤细胞均有良好的抗增殖活性,其中1a的活性略高于1b;1a能有效抑制Hela细胞转移,并使Hela细胞周期阻滞在S期。 相似文献
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介孔分子筛MCM-41 依次与3-氯丙基三乙氧基硅烷、环己二胺和三唑醛反应, 得到席夫碱修饰的新型介孔分子筛MCM-41 催化剂. 通过傅里叶变换红外光谱(FTIR)和X 射线多晶衍射(XRD)等方法对所得催化剂进行表征. 以过氧化氢为氧源, 介孔分子筛MCM-41 负载的席夫碱为催化剂, 研究了α,β-不饱和酮的环氧化反应, 考察了金属盐、溶剂、催化剂用量、反应时间等因素对环氧化反应的影响. 结果表明, 在室温下乙腈溶剂中, α,β-不饱和酮的环氧化反应在短时间内均以很高的产率(高达99%)得到了相应的产物. 同时, 对催化剂的重复利用进行了研究, 发现重复使用四次, 仍能以较高产率得到环氧化产物. 相似文献
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将介孔分子筛MCM-41依次与3-氯丙基三乙氧基硅烷、二氨基硫脲和水杨醛反应,得到席夫碱修饰的介孔分子筛MCM-41催化剂,以过氧化氢为氧源,研究了其与K2CO3共同催化α,β-不饱和酮的环氧化反应。 化合物的结构经1H NMR和IR分析确认。 考察了金属盐、溶剂、催化剂用量、反应时间等因素对环氧化反应的影响。 结果表明,室温下α,β-不饱和酮的环氧化反应在短时间内均以较高的产率(最高达93%)得到了相应的产物。 同时,对催化剂的重复利用进行了研究,发现重复使用4次,仍能以较高产率得到环氧化产物。 相似文献
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The reaction of β,β-dicyanostyrene derivatives(1) with 1,3-dibromo-5,5-dimethylhydantoin(DBDMH) was systematicly studied. The reaction could generate different products when promoted by different mild bases. When the reaction was promoted by NaOAc(100%, molar ratio to compound 1), β,β-dicyanostyrene derivatives could be directly converted into corresponding α,β-dehydroamino derivatives in good to excellent yields in one-pot. When the reaction was promoted by K3PO4(80%, molar ratio to compound 1), the corresponding α,β-dehydroamino and double-α,β-dehydroamino compounds were simultaneously obtained and the total conversion of β,β-dicyanostyrene derivatives was up to 90% or higher. 相似文献
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3-甲基-2-丁烯酸乙酯4经SeO2反式氧化、还原、溴化得到关键中间体4-溴-3-甲基-(2E)-丁烯酸乙酯7.7与三苯基胂反应生成季8.二氢香茅醛与8在K_2CO_3-乙醇-微量水的存在下反应,得到(2E,4E)-3,7,11-三甲基-2,4-十二碳二烯酸乙酯1a及其(2Z,4E)-异构体1b,产率74%。该反应具有(4E)-立体选择性,同时C-2双键发生部分构型转化。 相似文献
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以2-吲哚酮衍生物(1a~1c)与醛(2a~2n)为原料,通过克脑文格尔反应和酰化反应得到17个(E)-1-乙酰基亚苄基吲哚酮衍生物(1~17),其结构经1HNMR、 13CNMR和MS(ESI)进行表征。采用CTG法评价了目标化合物1~17对人非小细胞肺癌细胞(A-549),人乳腺癌细胞(MCF-7)和人胃腺癌细胞(BGC-823)3种肿瘤细胞增殖的抑制活性。结果表明:化合物16对三种肿瘤细胞具有显著的抑制活性,IC50值分别为0.50±0.03(A549)、 0.20±0.02(MCF-7)和0.34±0.04μM(BGC-823),尤其是对MCF-7的抗增殖活性与阳性对照阿霉素相当。
相似文献
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The reaction of electron-deficient cyclopropane derivatives, cis-1-methoxycarbonyl-2-aryl-6,6-dimethyl-5,7dioxospiro[2,5]octa-4,8-diones with benzoylmethylenetriphenylarsorane (2) and methoxycarbonylmethylenetriphenylarsorane (4) was found to form cis,trans-l-methoxycarbonyl-2-aryl-3-benzoyl-7,7-dimethyl-6,8-dioxospiro[3,5]nona-5,9-dione (3a-3e) and trans,cis,trans-5-[2‘-methoxycarbonyl-2‘-(triphenylarsoranylidene)acetyl]-6oxo-3-aryl-tetrahydro-pyran-2,4-dicarboxylic acid dimethyl esters (5a-5c) respectively with high stereoselectivity. The possible reaction mechanisms for the formation of the different products were also orooosed. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(33):10000-10003
The first highly enantioselective, diastereoselective, and regioselective [2,3]‐rearrangement of iodonium ylides has been developed as a general solution to catalytic onium ylide rearrangements. In the presence of a chiral copper catalyst, substituted allylic iodides couple with α‐diazoesters to generate metal‐coordinated iodonium ylides, which undergo [2,3]‐rearrangements with high selectivities (up to >95:5 r.r., up to >95:5 d.r., and up to 97 % ee ). The enantioenriched iodoester products can be converted stereospecifically into a variety of onium ylide rearrangement products, as well as compounds that are not accessible by classical onium ylide rearrangements. 相似文献