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1.
合成了一系列新型的芘标记含溴亲核阴离子的氮杂环卡宾前驱体化合物,接枝卤化锌后获得具有CO2捕获能力以及路易斯酸碱位点的NHC-PDBI-ZnX2(X=Cl、Br、I)催化剂,通过1H NMR、13C NMR 、XPS、FT-IR、13C CP-MAS NMR和ICP-AES表征技术对该类催化剂结构和化学性质进行了表征。氮杂卡宾锌配合物被证明是有效的单组分多功能催化剂,对环氧丙烷和CO2的环加成反应显示出较高的催化活性和选择性。最佳活性的NHC-PDBI-ZnI2催化剂在120℃、3.0MPa、2.0h较温和条件下,取得98%以上碳酸丙烯酯收率。该催化剂还具有优异的底物普适性和循环使用稳定性,归因于路易斯酸性Zn 2 与NHC-PBDI主链形成的强共价键。此外,结合FTIR等表征推测了反应机理,其中NHC-PDBI-ZnX2的卡宾位吸附活化CO2以及路易斯酸碱位点开环的协同效应促进了环加成反应在无溶剂和助催化剂的条件下有效地进行。  相似文献   

2.
江鹏  刘云龙  王艳  王飞军 《合成化学》2021,29(8):644-649
以噁唑啉和苄溴为原料,合成了一种卡宾前体盐中间化合物。该前体盐与Pt(COD)Cl2在乙腈中回流反应,合成了一种具有轴手性的噁唑啉-铂卡宾络合物,其结构经1H NMR, 13C NMR和X-ray表征。结果表明:反应只能得到(aS,S)构型的轴手性噁唑啉-铂卡宾络合物。   相似文献   

3.
以环庚酮及环己(庚)胺为起始原料,经溴代、环化、脱硫等反应,以良好的收率合成了环烷基取代的新型噻唑骨架的氮杂环卡宾催化剂。结果表明,在该催化剂催化下成功地实现了烯烃的自由基氟烷基酰化反应,以中等的收率完成了三种类型的γ-氟烷基取代酮的高效合成。所得化合物通过1H NMR, 13C NMR, 19F NMR和HR-MS(ESI-TOF)进行表征。  相似文献   

4.
以5 mol%布朗斯特酸(±)-BNPA为催化剂,含CF3氮杂对亚甲基苯醌与吲哚为原料,通过1,6-共轭加成反应合成了7个结构新颖的含CF3的吲哚类化合物,收率80%~87%,其结构经1H NMR, 13C NMR, 19F NMR和HR-MS(ESI)表征,并对反应机理进行了探讨。  相似文献   

5.
邵莺  潘乐昊  田世杰  吴锦 《合成化学》2020,28(11):955-962
发展了一种铑催化的3-乙烯基吲哚与芳基三氮唑的环合反应。通过优化催化剂、反应温度、时间和eq.比等反应条件,最终在氩气保护下,以2.5 mol% Rh2(OAc)4为催化剂,1,2-二氯乙烷为溶剂,3-乙烯基吲哚和芳基三氮唑的eq.比为1/2时,60 ℃反应6~12h,一步合成了15个新型的3-(2,3-二氢吡咯)吲哚衍生物(3aa~3al, 3ba~3da),其结构经1H NMR,13C NMR和HR-MS(ESI)表征。   相似文献   

6.
以2-氧硫叶立德芳乙酮类化合物为原料,通过弱配位辅助的Ru催化C-H活化过程简捷高效地构建了异香豆素类化合物,并推测了反应机理。以[RuCl2(p-cymene)]2为催化剂,HFIP为溶剂,AgNTf2为添加剂,KOAc为碱,以33%~91%收率合成了14个目标产物,其中3个化合物未见文献报道,其结构经1H NMR, 13C NMR和HR-MS(ESI)表征。反应条件温和,反应位点选择性高,底物普适性好,耐受多种官能团。  相似文献   

7.
陈筱诚  余辉  郭娟  贺鹤勇  傅正文  龙英才 《化学学报》2010,68(21):2161-2166
以甲胺水溶液为改性剂, 高硅Y型沸石可在常温下吸附甲胺(MA)制备有机-无机杂化酸碱双功能高硅Y型沸石材料. X 射线粉末衍射(XRD), 固体29Si魔角核磁共振(13C及29Si MAS NMR)表征表明甲胺分子与高硅Y型沸石骨架相互作用导致沸石结构发生变化, 骨架上生成新的Si—N键及Si—OH. 以热重分析(TG/DTG), NH3, CO2程序升温脱附(NH3-TPD和CO2-TPD)研究杂化Y型沸石的酸碱性质及其经不同温度焙烧后的变化, 结果表明, 杂化后沸石的酸/碱量, 尤其是后者明显增大, 其原因是骨架上生成了新的Si—OH及Si—N键.  相似文献   

8.
在可见光促进下,以介孔氮化碳(mpg-C3N4)作为可回收的光催化剂,Na2CO3作为添加剂,室温O2氛围中,苄基卤化物氧化合成相应的芳基醛或酮及其衍生物(2a~2u),其结构经1H NMR,13C NMR和MS(ESI)表征。mpg-C3N4的结构经XRD, BET和紫外-可见漫反射光谱表征。以4-甲基氯苄(1a)作为模板反应,探究了催化剂、溶剂、反应时间和催化剂用量对反应的影响。在最优反应条件下, 2a~2u收率可达63%~87%。通过催化剂稳定性实验发现催化剂可以稳定循环5次。   相似文献   

9.
以3-氯氧化吲哚为原料,在无催化剂条件下发生SN1反应,合成了18个新型的3-吲哚-四取代氧化吲哚,产率34%~77%,其结构经1H NMR, 13C NMR和HR-MS(ESI-TOF)表征。  相似文献   

10.
以苯乙酮类化合物为原料,三氟甲磺酸铁[Fe(OTf)3]为催化剂,经自身三聚缩合反应合成了18个1,3,5-三苯基苯类化合物(2a~2r),其中2o~2r为新化合物,其结构经1H NMR, 13C NMR和HR-MS(ESI)表征。研究了催化剂种类及其用量、溶剂、温度和反应时间对2a产率的影响。结果表明:在最佳反应条件[Fe(OTf)3 0.02 eq.,甲苯为溶剂,于100 ℃反应4 h]下,2a产率91%。  相似文献   

11.
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%.  相似文献   

12.
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.  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
Zhanhui Yang  Shiyi Yang  Jiaxi Xu 《Tetrahedron》2017,73(23):3240-3248
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.  相似文献   

18.
19.
《Tetrahedron》2014,70(21):3377-3384
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.  相似文献   

20.
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.  相似文献   

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