具有共轭体系的酮类烯醇硅醚与全氟碘代烷的反应

应用连二亚硫酸钠的引发，通过全氟碘代烷与醛类，酮类烯醇硅醚的反应，合成α－全氟烷基羰基类化合物的方法。利用该方法，还可以用“一锅法”合成含氟β－二酮类化合物。本文报道了在类似的反应条件下，与苯环或双键共轭的烯醇硅醚和全氟碘代反应的结果。     

含萘并呋喃基团冠醚的合成及离子选择性研究

以2-羟基-1-萘甲醛和2-羟甲基冠醚为原料,合成3种新的含萘并呋喃基团冠醚(3a-3c),并经1 H NMR,13C NMR,MS及元素分析确证.碱金属和碱土金属离子的加入对体系的最大吸收波长影响不大.Li+使3b摩尔吸光度变大,Ca2+和Ba2+引起3a-3c最大发射波长λem发生相对较大红移,同时使其荧光强度降低.     

Reaktionen von elektronenreichen heterocyclen mit orthocarbonsäure-derivaten. I. Zum reaktionsverhalten von acyclischen orthoestern mit indolen unter säurekatalyse

By kinetic controlled reaction of alkoxycarbenium-ions 1a-1d , generated in the medium, with the indoles 2a-2c the methanes 3 , 4 or the ketones 5 and 6 are the single products. In the reaction with 1d the minimum of reactivity is achieved. The experimental condition of the reactions allow an estimation of the reactivity of 1a-1d and 2a-2c .     

Cu(II) acetate- and Mn(III) acetate-mediated radical reactions of [60]fullerene with ketonic compounds

The copper(II) acetate monohydrate- or manganese(III) acetate dihydrate-mediated reaction of [60]fullerene with beta-keto esters 1a-1c or with beta-diketones 1d,1e in the presence of 4-dimethylaminopyridine afforded only dihydrofuran-fused C60 derivatives 2a-2e. However, aromatic methyl ketones 3a-3c gave two kinds of products: methanofullerenes 4a-4c and dihydrofuran-fused C60 derivatives 5a,5b. Possible reaction mechanisms are proposed.     

Synthesis of N-Substituted Azetidin-3-ones

Addition of RC(0)Cl (R = OEt, Me, or Ph) across the highly strained N-C(3) o-bond in 3-bromomethyl-l-azabicyclo[1.1.0]butane (1) afforded the corresponding N-acyl-3-bromomethyl-3-chloroazetidines (2a-2c, respectively). Subsequent zinc promoted eliminative dehalogenation of 2a-2c produced the corresponding N-acyl-3-methyleneazetidines (3a-3c, respectively). Finally, ozonolysis of 3a-3c afforded the corresopnding N-acylazetidin-3-ones (4a-4c, respectively).     

Spiropentane mimics of nucleosides: analogues of 2'-deoxyadenosine and 2'-deoxyguanosine. Synthesis of all stereoisomers, isomeric assignment, and biological activity

Synthesis of spirocyclic analogues of 2'-deoxyadenosine and 2'-deoxyguanosine (12a-15a and 12b-15b) is described. Rhodium-catalyzed reaction of ethyl diazoacetate with methylenecyclopropane 19, obtained from 2-bromo-2-bromomethylcyclopropane 17 via debromination (16), reduction (18), and acetylation (19), gave a mixture of all four isomeric spiropentanes 20a-20d. Hydrolysis afforded hydroxy carboxylic acids 21a-21d. Acetylation of separated proximal + medial-syn isomers 21a + 21b and medial anti + distal isomers 21c + 21d furnished acetates 22a + 22b and 22c + 22d. Curtius rearrangement effected by diphenylphosphoryl azide in tert-butyl alcohol performed separately with mixtures 22a + 22b and 22c + 22d led to BOC-amino spiropentanes 23a + 23b and 23c + 23d. After deacetylation all isomers 24a-24d were separated and deprotected to give aminospiropentane hydrochlorides 25a-25d. Free bases were of limited stability. The heterocyclic moieties were introduced into individual isomers 25a-25d via 6-chloropurine derivatives 26a-26d or 30a-30d. Ammonolysis of 26a-26d furnished the adenine isomeric series 12a-15a, whereas guanine derivatives 12b-15b were obtained by hydrolysis of 30a-30d with formic acid. The isomeric assignments followed from IR spectra of BOC-aminospiropentanes 24a-24d and NMR spectra of 12a-15a including NOE and (H,H) COSY. The proximal and medial-syn isomers 12a and 12b were modest inhibitors of human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) in culture, whereas the medial-anti isomer 12c was a substrate for adenosine deaminase. The distal isomer 15b was an anti-EBV agent. The medial-syn phosphoralaninate 34 was an effective inhibitor of HCMV replication in vitro. It was also active against herpes simplex virus type 1 (HSV-1), varicella zoster virus (VZV), human immunodeficiency virus (HIV-1), hepatitis B virus (HBV), and EBV with a varying degree of cytotoxicity.     

Synthesis of Conformationally Locked 2＇-Deoxy-2＇-nucleobase-5＇- Isonucleosides: 2＇-Deoxy-2＇-nucleobase-5＇ deoxy-1＇, 4＇ :3＇, 6＇-dianhydro-D-mannitol

Novel bicyclic isonucleosides, 2＇ -deoxy- 2＇ -nucleobase- 5＇ -deoxy- 1＇ , 4＇ : 3＇ , 6＇ -dianhydro D-mannitol 10a-10c, were synthesized from D-glucose. The computer-assisted molecular simu lation indicated that the sugar conformations of compounds 10a-10c were restricted to N-con formation.     

Asymmetric Photocatalyzed Addition of Cyclic Ammes to the Chiral 5-(l)-Menthyloxy-2(5H)-furanone

Inrecentyears,considerableattentionhasbeenfocusedonthesynthesisandpropertiesofchiralbutenolidesbecauseoftheirmultifunctionalnatureandversatilityonenantioselectivetransformationreactionsl'2.Despiteextensivestudiesofthisresearchworkonasymmetricreactionsbutlittleefforthasbeendevotedtowardsphotochemicalsynthesisofsomechiraly-substituted2-(SH)-furanones'.Amongthepreviouswork,thetertiaryammesusedinthephotocatalysedconjugateadditionsto5-substituted2(5H)foranoneswerethefirstexamples",andthesecondaryc…     

The reactions of perfluoro- and α,α-dichloropolyfluoroalkanesulfinates

Sodium perfluoroalkanesulfinate, R_FSO₂Na [R_F?Cl(CF₂)₄, 1a; CF₃(CF₂)₅, 1b; Cl(CF₃)₆, 1c] reacted with bromine in aqueous solution to give the corresponding sulfonyl bromide R_FSO₂Br (2a-2c) and in acetonitrile or acetic acid, to form perfluoroalkyl bromide R_FBr (3a-3c). Heating in acetonitrile at 80°C, 2a-2c were converted smoothly into 3a-3c. However, reaction of sodium α,α-dichloropolyfluoroalkanesulfinate RCCl₂SO₂Na (R?CF₃, Cl(CF₂)n, n=2, 4, 6, 5a-5d) with bromine in aqueous solution gave directly the corresponding bromoalkanes 1-bromo-1,1-dichloropolyfluoroalkane RCCl₂Br (6a-6d). In aqueous potassium iodide solution, 1a-1c, 5a and 5b also reacted with iodine to form the corresponding iodo-polyfluoroalkane 4a-4c, 7a and 7b directly. 6a and 7a underwent free radical addition to alkene readily in the presence of free radical initiator and reacted with Na₂S₂O₄ in the usual way to form α,α-dichloropolyfluoroethane sulfinate (5a). 5a was stable in strong acid, but reacted with strong base to yield 10. 5a was oxidised by hydrogen peroxide to the sulfonate 11 and reduced by zinc in dilute acid to from the α-chloro sulfinate 12.     

Synthesis of methyl-substituted lariat ethers containing a 13-crown-4 ring

Convenient synthetic procedures for preparing two kinds of methyl-substituted lariat ethers containing a 13-crown-4 ring, 1 and 2 , are described. Compounds 1a-1c were obtained from the reaction of 2-bromomethyl-2-methyl-13-crown-4 ( 5 ) with the appropriate alkoxide. Compound 5 was prepared without the need for prior protection of the bromomethyl group. For the synthesis of compounds 2a-2c , which possess an electron-donating group on the central carbon of the trimethyl moiety of the 13-crown-4 ring, the substituents were introduced before cyclization.     

新型1,2,3-三唑类化合物的合成及抗菌构效关系

根据活性基团拼接原理, 以4-取代-苯胺为原料, 经重氮化、 关环和缩合反应合成了17个化合物1-(4-取代苯基)-5-取代苯基亚氨基-4-取代-1,2,3-三唑(7a~7c和13a~13d)和1-(4-取代苯基)-5-取代苄基氨基-4-取代-1,2,3-三唑(5a~5c, 10a~10c和14a~14d), 其中化合物5a~5c, 7b, 7c, 10a, 10c, 13b~13d和14b~14c为新化合物, 对所制备化合物的结构进行了表征. 生物活性测试结果表明, 所有化合物均表现出一定的抑菌活性, 对大肠杆菌的抑菌活性均优于氟康唑; 化合物7a和10c对金黄色葡萄球菌的抑制活性明显优于氟康唑; 而化合物13a和13d则对白色念球菌表现出良好的抑制活性, 与三氯生相当.     

9,10-2H-9-氧杂-10-磷杂菲-10-氧化物基1,3-苯并噁嗪树脂的合成与表征

以水杨醛、对甲基苯胺(或对氟苯胺,对甲氧基苯胺)、9,10-2H-9-氧-10-磷杂菲-10-氧化物(DOPO)及甲醛为原料,通过三步反应合成了三个含DOPO基的1,3-苯并噁嗪化合物3a-3c.第一步,水杨醛与对位取代苯胺进行缩合反应生成亚胺(1a-1c);第二步,DOPO对亚胺进行加成反应得到仲胺(2a-2c);第三步,仲胺与甲醛在强酸性离子交换树脂催化下进行关环反应形成含DOPO的1,3-苯并噁嗪树脂.采用红外光谱、核磁共振谱和质谱等表征了化合物3a-3c,同时采用热失重分析技术测定了其热稳定性.结果表明,3a-3c由两对对映体组成,质谱条件下2a-2c和3a-3c均经裂解失去稳定的DOPO基团;3a-3c热降解反应包含两个热失重过程,分别在250和400℃下出现最大热释放速率.     

4-Cyano-2-oxo-1,2,4-oxadiazolo[2,3-a]quinoxaline 5-N-oxides. New synthetic method and reaction with alcohols. Potential cytotoxic activity

Several quinoxaline 1,4-di-N-oxides have been shown to be efficient and selective cytotoxins for hypoxic cells. We present now a series of 4-cyano-2-oxo-1,2,4-oxadiazolo[2,3-a]quinoxaline 5-N-oxides 2a-2k . They were prepared starting from 3-amino-2-quinoxalinecarbonitrile 1,4-di-N-oxides 1a-1k and 2-chloroethyl isocyanate in dry dioxane at 100–110°. A reaction mechanism is proposed. The treatment of 1a with phenyl isocyanate afforded 2a . Reaction of 2c with silica gel yielded 1c . Compounds 2a-2g were heated in the presence of ethanol and 2-propanol giving the corresponding carbamates 3a-3g and 4a-4g . Compound 2d was already obtained by heating a mixture of 1d and ethyl chloroformiate. Compound 2b was prepared when the carbamate 3b was heated at 150°. Quinoxalines were tested as cytotoxic agents both in oxic and hypoxic cells. The most interesting compounds were 3g and 4g .     

金刚烷负载高价碘试剂的合成及氧化反应活性

以1,3,5,7-四氨基金刚烷与4-碘苯基酰氯为原料,经酰化、氧化反应,制备了新型金刚烷负载的高价碘试剂(1a-1c)。 酰化反应以CH₂Cl₂为溶剂,首先,0 ℃,反应4 h,然后室温反应2 h,投料比n(1,3,5,7-四氨基金刚烷)∶n(4-碘苯基酰氯)∶n(三乙胺)=1∶4.4∶5.2。 氧化反应以CH₂Cl₂/醋酸(体积比1∶1)为溶剂,间氯过氧苯甲酸(m-CPBA)为氧化剂,室温反应12 h,投料比n(2)∶n(m-CPBA)=1∶12。 化合物1a,1b和1c的总收率分别为86.4%、85.4%和85.3%。 以化合物1a-1c为氧化剂,在四甲基哌啶氮氧化物(TEMPO)催化下各类醇被氧化成相应的醛或酮,产物收率87%~100%。 负载碘苯2a-2c可以被方便地分离和回收,平均回收率98%,可再经氧化,高收率转化成化合物1a-1c,循环利用。     

New n-type organic semiconductors: synthesis, single crystal structures, cyclic voltammetry, photophysics, electron transport, and electroluminescence of a series of diphenylanthrazolines

The synthesis, properties, and electroluminescent device applications of a series of five new diphenylanthrazoline molecules 1a-1e are reported. Compounds 1b, 1c, and 1d crystallized in the monoclinic system with the space groups P2(1)/c, C2/c, and P2(1)/c, respectively, revealing highly planar molecules. Diphenylanthrazolines 1a-1e have a formal reduction potential in the range -1.39 to -1.58 V (versus SCE) and estimated electron affinities (LUMO levels) of 2.90-3.10 eV. Compounds 1a-1e emit blue light with fluorescence quantum yields of 58-76% in dilute solution, whereas they emit yellow-green light as thin films. The diphenylanthrazoline molecules as the emissive layers in light-emitting diodes gave yellow light with a maximum brightness of 133 cd/m(2) and an external quantum efficiency of up to 0.07% in ambient air. Bilayer light-emitting diodes using compounds 1a-1e as the electron-transport layer and poly(2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene) as the emissive layer had a maximum external efficiency of 3.1% and 2.0 lm/W and a brightness of up to 965 cd/m(2) in ambient air. These results represent enhancements of up to 50 times in external quantum efficiency and 17 times in brightness when using 1a-1e as the electron-transport materials in polymer light-emitting diodes. These results demonstrate that the new diphenylanthrazolines are promising n-type semiconductors for organic electronics.     

Stereoselective synthesis and conformational study of novel 2',3'-Didehydro-2',3'-dideoxy-4'-selenonucleosides

Stereoselective synthesis of novel 2',3'-didehydro-2',3'-dideoxy-4'-selenonucleosides (4'-seleno-d4Ns) 4a- c was accomplished via 4'-selenoribofuranosyl pyrimidines 11a- c, as key intermediates. 4'-Selenoribofuranosyl pyrimidines 11a- c were efficiently synthesized from d-ribose or d-gulonic gamma-lactone using a Pummerer-type condensation as a key step. Introduction of 2',3'-double bond was achieved by treating cyclic 2',3'-thiocarbonate with 1,3-dimethyl-2-phenyl-1,3,2-diazaphospholidine.     

Microwave-Assisted Synthesis of Some Bi- and Tricyclic Pyrimidine Derivatives

Pyrimidine derivatives 4a-4c was prepared by a Biginelli cyclocondensation of g -ketoesters, aryl aldehydes, and thiourea derivatives under microwave irradiation. A simple and fast synthesis of bicyclic pyrimidine derivatives 6a-6c was performed by microwave-assisted reaction of 4a-4c with bromomalononitrile ( 5 ). Reaction of bicyclic pyrimidines 6a-6c with HCO 2 H and HONH 3 Cl under microwave irradiation gave tricyclic pyrimidines 7a-7c and 8a-8c respectively.     

Polyimides from dianhydrides and bis(p-aminophenyl) alkane diamines. I

Polyimides were synthesized from pyromellitic dianhydride (PMDA), 3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA), and three different diamines with the following general structure: where R is ethyl, propyl, or isobutyl. The poly(amic acids) obtained had inherent viscosities ranging from 0.30 to 0.93 and were thermally/chemically converted to polyimides. The thermal stability of the polyimides was evaluated by using dynamic thermogravimetric analysis in air. Physical and thermal properties of these polyimides were compared with that obtained by reacting 2,2-bis(4-aminophenyl) propane and PMDA/BTDA.     

Isostructural potassium and thallium salts of sterically crowded triazenes: a structural and computational study

Because of their similar cationic radii, potassium and thallium(I) compounds are usually regarded as closely related. Homologous molecular species containing either K(+) or Tl(+) are very rare, however. We have synthesized potassium and thallium salts MN3RR' derived from the biphenyl- or terphenyl-substituted triazenes Tph2N3H (1a), Dmp(Mph)N3H (1b), Dmp(Tph)N3H (1c), and (Me4Ter)2N3H (1d) (Dmp=2,6-Mes 2C6H3 with Mes=2,4,6-Me3C6H2; Me4Ter=2,6-(3,5-Me2C6H3)2C6H3; Mph=2-MesC6H4; Tph=2-TripC6H4 with Trip=2,4,6-(i)Pr3C6H2). The potassium complexes 2a- d were obtained in almost quantitative yield from the reaction of 1a- d with potassium metal in n-heptane. Metalation of 1a- d with TlOEt afforded the thallium triazenides 3a- d in high yields. All new compounds have been characterized by (1)H and (13)C NMR spectroscopy, elemental analysis, and X-ray crystallography and for selected species by melting point (not 3b), IR spectroscopy (2a, 2d, 3a, 3c, 3d), and mass spectrometry (2a, 3c). In the solid-state structures of monomeric 2a and 3a, quasi-monomeric 2b, 3b, 2c, and 3c, and dimeric 2d and 3d additional metal-eta (n)-pi-arene-interactions to the flanking arms of the biphenyl- and terphenyl groups in the triazenide ligands of decreasing hapticity n are observed. Remarkably, all homologous potassium and thallium complexes crystallize in isomorphous cells. For 2a and 3a, the nature of the M-N and M...C(arene) bonding was studied by density functional theory calculations.     

Novel derivatives of the benzo[b][1,6]naphthyridine system

An efficient synthesis of 2‐hydroxy‐6‐methylbenzo[b][1,6]naphthyridin‐1(2H)‐one was devised. The hydroxy group was alkylated, acylated and replaced by hydrogen. Electrophilic nitration, bromination and chlorosulfonation occurred readily in the 4‐position. From the last, various sulfonamide derivatives were prepared. A selection of the products was screened by the National Cancer Institute. Cytotoxicities were generally low.