端位炔酮与有机锌试剂的自缩合反应

端位炔酮与有机锌试剂CF3CO2ZnEt作用发生自缩合反应,得到较高产率的β取代的Morita-Bayllis-Hillman产物,提供了三取代烯烃化合物的合成方法;而与有机锌试剂CF3CO2ZnCH2I作用时,烷基炔酮不发生反应,只有活性较高的芳基炔酮才能进行反应,得到中等产率的2,5-二氢呋喃衍生物。     

水中全氟烷基醚类羧酸的超高效液相色谱-串联质谱检测方法研究

电喷雾离子源条件下全氟烷基醚类羧酸(PFECA)发生源内裂解和CO2中性丢失,导致其准分子离子峰的丰度降低,影响该类化合物的检测灵敏度.该文选择[CF3(CF2)nO]或[M-H-CO2]作为母离子,其他次级氟化烷氧基和烷基片段作为子离子,可将全氟烷基醚类羧酸的质谱响应最大提高4个数量级.结合液液萃取,对水样中4种全氟...     

可见光诱导的共轭磺酰胺串联脱砜/环化反应

发展了一种可见光诱导的共轭磺酰胺串联脱砜/环化,合成全氟烷基化吲哚酮或α-芳基酰胺的方法。此反应以多氟烷基碘或溴为氟源,在发光二极管蓝光灯照射下,利用面式-三(2-苯基吡啶)合铱催化N-烷基-N-甲基丙烯酰基苯磺酰胺经过串联自由基加成/β-芳基迁移/脱砜环化过程,一步构筑两重碳-碳键,以41%~78%的产率合成了一系列含氟吲哚酮或α-芳基酰胺。此方法底物适用范围广,反应条件温和(室温),催化体系绿色,为具有潜在生理活性的含氟吲哚酮及α-芳基酰胺的合成提供了一条高效、快捷的新途径。     

二茂钛含氟有机酸衍生物的质谱研究

本文研究了二茂钛含氟长链有机酸衍生物(1～3)和具有环状结构的新型二茂钛全氟有机酸(4～7)的电子轰击质谱(EIMS)和负离子化学电离质谱(NICIMS)。在EI谱中出现弱的或不出现M~+,1～7均以CpTiF_2离子为基峰。高质量区的主要特征碎片离子有[M-·cp]~+、[M-R]~+(1～3)和氟重排离子。在低质量区出现一系列二茂钛及茂钛氟重排离子。 1、4～7的NICI(CH_4)质谱中,4、5出现强的M~-离子峰,1出现[M-1]-离子峰,有两个钛的环状结构化合物6和7出现双电荷M~=离子峰,而不出现M~-。     

全氟烷基卤化物作为含氟砌块在构建氟烷基取代杂环化合物中的研究进展

有机氟化学和杂环化学的研究对药物研发、新材料制备等方面具有重要意义.过去几年中,利用高度商业化、低毒性、廉价、稳定、易操作的全氟烷基卤化物为含氟砌块构建氟烷基取代杂环化合物取得了重要进展.本综述将全氟烷基卤化物作为含氟砌块参与构建杂环化合物的报道进行总结:(1)通过全氟烷基卤化物的单个碳卤键官能化构建杂环化合物;(2)...     

第五 六族元素的有机化合物在有机合成中应用的研究 XXX。苯甲酰基亚甲基三苯基膦、胂与2-全氟炔酸甲酯的反应以及4-全氟烷基-6-苯基-2-吡喃酮的合成

苯甲酰基亚甲基三苯基膦、胂(1)与2-全氟炔酸甲酯(2)反应,生成主要产物3和少量4,总产率在95%左右,证明了3和4的结构,并推测了反应机理,胂化合物的3d～3f在含水甲醇中加热,发生砷-碳键断裂,生成4-全氟烷基-6-苯基-2-吡喃酮(7),产率40～83%。     

第五、六族元素的有机化合物在有机合成中应用的研究 ⅩⅩⅩ.苯甲酰基亚甲基三苯基膦、胂与2-全氟炔酸甲酯的反应以及4-全氟烷基-6-苯基-2-吡喃酮的合成

苯甲酰基亚甲基三苯基膦、胂(1)与2-全氟炔酸甲酯(2)反应,生成主要产物3和少量4,总产率在95％左右.证明了3和4的结构,并推测了反应机理.胂化合物3d～3f在含水甲醇中加热,发生砷—碳键断裂,生成4-全氟烷基-6-苯基-2-吡喃酮(7),产率40～83％.     

全氟烷基碘化物化学的新进展

本文讨论了全氟烷基碘化物在金属有机化学、自由基化学以及有机合成上的新进展与应用。近来对全氟烷基腆化物的研究兴趣日增,主要因为由R班(全氟烷基碘化物)可以方便地获得各种全氟烷基的金属有机化合物和各种全氟烷基自由基.R班也是一个重要的中间体,由它出发可以得到有各种官能团的含氟有机化合物,如一50:CI;一C00H;一poaH;一CF=CF:;一NO:;一Mgl;一X(X表示碘以外的其它卤素);一H;一SR等。另外,虽然在碳氟和碳氢碘化物中,碳     

无催化剂条件下的全氟烷基取代的1H-苯并[b][1,4]二氮-2(3H)-酮的简易合成

1,5-苯并二氮-2-酮作为一个独特的骨架广泛存在于很多具有生理活性的化合物中,而全氟烷基的引入影响到有机化合物的理化性质以及生理活性的改变.因此将全氟代烷基引入1,5-苯并二氮-2-酮的方法的研究正变得日趋重要.发展了一个制备全氟代烷基取代的1,5-苯并二氮-2-酮的简易方法.采用全氟代炔酸甲酯为含氟砌块,与邻芳基二胺,以无水甲苯为溶剂,在无催化剂存在条件下,80℃反应24 h,以较好的收率顺利得到4-全氟烷基-1,3-二氢-1,5-苯并二氮-2-酮类化合物.     

钯催化下全氟碳负离子的产生及其反应

2-三氟甲基-3-氧杂-八氟己酸烯丙酯或2,5-二(三氟甲基)-3,6-二氧杂-十二氟壬酸烯丙酯可在钯的作用下产生相应的全氟碳负离子. 这些碳负离子能够质子化或者对取代苯甲酰氯发生亲核进攻, 后者为芳基氟烷基酮的合成提供了一条简捷途径. 另一方面,上述含氟酸的甲酯和取代苯甲酰氯在钯的作用下同样能发生反应而生成相应的芳基氟烷基酮.     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.