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文章名     作者     期刊名     摘要     卷     期         如果没有找到您所需要的文献，请点击 ——此处申请     共20条记录   Ligand Effects on the Mechanisms of Thermal Bond Activation in the Gas-Phase Reactions NiX+/CH4 -> Ni(CH3)(+)/HX (X = H, CH3, OH, F) [作者：Schlangen, M; Schwarz, H,期刊：Helvetica Chimica Acta, 页码：2203-2210 , 文章类型： Article，,卷期：2008年91-12] The thermal ion-molecule reactions NiX+ + CH4 -> Ni(CH3)(+) + HX (X = H, CH3, OH, F) have been studied by mass spectrometric methods, and the experimental data are complemented by density functional theory (DFT)-based co... Photocyclodimerization of 5-Methyl-2H-pyran-3(6H)-one [作者：Groesch, L; Kopf, J; Margaretha, P,期刊：Helvetica Chimica Acta, 页码：2211-2215 , 文章类型： Article，,卷期：2008年91-12] The structures of the main products resulting from photocyclodimerization of the title compound 2 and of other 3-methyl-substituted 'oxacyclohex-2-en-1-ones' (=dihydropyranones) were determined by X-ray crystallography. ... Photocycloaddition Reactions of 2-(Alk-3-en-1-ynyl)cyclohex-2-enones [作者：Moebius, J; Margaretha, P,期刊：Helvetica Chimica Acta, 页码：2216-2221 , 文章类型： Article，,卷期：2008年91-12] The newly synthesized 2-(alk-3-en-1-ynyl)cyclohex-2-enones 4 undergo photodimerization (chemo- and regio-)selectively at the exocyclic C=C bond to give diastereoisomeric mixtures of 1,2-dialkynyl-1,2dimethylcyclobutanes.... Six New C-21 Steroidal Glycosides from Cynanchum bungei DECNE [作者：Gan, H; Xiang, WJ; Ma, L; Hu, LH,期刊：Helvetica Chimica Acta, 页码：2222-2234 , 文章类型： Article，,卷期：2008年91-12] Six new C-21 steroidal glycosides 1-6 were isolated from the stem parts of Cynanchum bungei DECNE. The structures of the new glycosides were determined on file basis of spectroscopic analysis, including 1D- and 2D-NMR an... A Concise Total Synthesis of Diospongins A and B [作者：Sabitha, G; Padmaja, P; Yadav, JS,期刊：Helvetica Chimica Acta, 页码：2235-2239 , 文章类型： Article，,卷期：2008年91-12] The total synthesis of the diarylheptanoids (-)-diospongin A (1) and 13 (2) was achieved stereoselectively via the delta-lactone intermediate 6. The key reactions involved are a stereoselective reduction of beta-keto est... Formal Synthesis of Natural 1,3-Polyol/alpha-Pyrone Diastereoisomers [作者：Sabitha, G; Gopal, P; Yadav, JS,期刊：Helvetica Chimica Acta, 页码：2240-2246 , 文章类型： Article，,卷期：2008年91-12] A stereoselective formal synthesis of diastereoisomers of 1,3-polyol/alpha-pyrone artifungal natural products isolated from Ravensara anisata has been achieved involving epoxide opening and asymmetric allylation as key s... Iridoids from the Bark of Alstonia scholaris [作者：Feng, T; Cai, XL; Du, ZZ; Luo, XD,期刊：Helvetica Chimica Acta, 页码：2247-2251 , 文章类型： Article，,卷期：2008年91-12] Four new 11-noriridoids named scholareins A-D (1-4), along with three known derivatives, isoboonein (5). alyxialactone (6). and loganin (7), were isolated from EtOH extracts of the bark of Alstonia scholaris bv chromatog... One-Pot Diastereoselective Synthesis of Densely Functionalized 2H-Indeno[2,1-b]furans. Single-Crystal X-Ray Structure of Dimethyl 8,8a-Dihydro-8-oxo-8a-(2,2,2-trichloroethoxy)-2H-indeno[2,1-b]furan-2,3-dicarboxylate [作者：Ramazani, A; Noshiranzadeh, N; Ghamkhari, A; Slepokura, K; Lis, T,期刊：Helvetica Chimica Acta, 页码：2252-2261 , 文章类型： Article，,卷期：2008年91-12] Highly reactive 1:1 intermediates were produced in the reaction of Ph3P and dialkyl acctylenedicarboxylates (=dialkyl but-2-ynedioates). Protonation of these intermediates by alcohols (2,2,2-trichloroethanol, propargyl a... Furostane-Type Steroidal Saponins from the Roots of Chlorophytum borivilianum [作者：Acharya, D; Mitaine-Offer, AC; Kaushik, N; Miyamoto, T; Paululat, T; Lacaille-Dubois, MA,期刊：Helvetica Chimica Acta, 页码：2262-2269 , 文章类型： Article，,卷期：2008年91-12] Four new furostanol steroid saponins, borivilianosides A - D (1-4, resp.), corresponding to (3 beta,5 alpha,22R,25R)-26-(beta-D-glucopyranosyloxy)-22-hydroxyfurostan-3-yl O-beta-D-xylopyranosyl-(1 -> 3)-O-beta-D-glucopyr... A New Insight into the Catalytic Decomposition of Ethyl Diazoacetate in the Presence of meso-Tetraarylporphyrin (=5,10,15,20-Tetraaryl-21H,23H-porphine) Complexes [作者：Gomes, ATPC; Leao, RAC; Alonso, CMA; Neves, MGPMS; Faustino, MAF; Tome, AC; Silva, AMS; Pinheiro, S; de Souza, MCBV; Ferreira, VF; Cavaleiro, JAS,期刊：Helvetica Chimica Acta, 页码：2270-2283 , 文章类型： Article，,卷期：2008年91-12] The decomposition of ethyl diazoacetate by several catalysts in the presence of meso-tetraarylporphyrin complexes with different electronic features was evaluated. The distribution of the obtained products (chlorins, bac... Withanolides from Physalis alkekengi var. francheti [作者：Li, YZ; Pan, YM; Huang, XY; Wang, HS,期刊：Helvetica Chimica Acta, 页码：2284-2291 , 文章类型： Article，,卷期：2008年91-12] Two new withanolides, namely (20S,27R)-15 alpha-acetoxy-5 alpha-chloro-6 beta,14 beta-dihydroxy-1oxowitha-2,24-dienolide (1) and (22R)-5 beta,6 beta:14 alpha,17:14 beta,26-triepoxy-2 alpha-ethoxy-13,20,22-trihydroxy-1,15... Dimeric Diterpenes from the Roots of the Mangrove Plant Ceriops tagal [作者：Chen, JD; Qiu, Y; Yang, ZW; Lin, P; Lin, YM,期刊：Helvetica Chimica Acta, 页码：2292-2298 , 文章类型： Article，,卷期：2008年91-12] Three new dimeric diterpenses. tagalsin L (1), tagalsin NI (2), and tagalsin N (3) were isolated front the roots of the mangrove plant Ceriops tagal. Their structures and relative configurations were elucidated by means ... Reductions of Benzene Derivatives Whose Benzylic Positions Bear Oxygen Atoms under Mild Conditions [作者：Menzek, A; Karakaya, MG; Kaya, AA,期刊：Helvetica Chimica Acta, 页码：2299-2307 , 文章类型： Article，,卷期：2008年91-12] Reductions of compounds whose benzylic positions bear O-atoms, such as benzyl alcohol, dibenzylether, styrene oxide, benzaldehyde, acetophenone, and benzophenone, to the corresponding non-conjugated dienes were performed... New Verticillane-Type Diterpenoids from the Taiwanese Soft Coral Cespitularia hypotentaculata [作者：Cheng, YB; Lo, KL; Chen, CY; Khalil, AT; Shen, YC,期刊：Helvetica Chimica Acta, 页码：2308-2315 , 文章类型： Article，,卷期：2008年91-12] Investigation of the MeOH/CH2Cl2 extract of the soft coral Cespitularia hypotentaculata collected in Taiwan has resulted in the isolation of four new verticillane-type diterpenoids, cespihypotins M-P (1-4). Compounds 2 a... Three New Arylnaphthalide Lignans from the Aerial Parts of Bupleurum marginatum WALL. ex DC. [作者：Liu, Y; Zhang, TT; Zhon, JS; Wang, Q,期刊：Helvetica Chimica Acta, 页码：2316-2320 , 文章类型： Article，,卷期：2008年91-12] Three new arylnaphthalide lignans, 5-(4-hydroxy-3-methoxyphenyl)furo[3',4':6,7]naphtho[2,3-d]-1,3-dioxol-6(8H)-one (1), 10-(4-hydroxy-3-methoxyphenyl)furo[3',4':6,7]naphtho[1,2-d]-1,3-dioxol-9(7H)-one (2), and 10-(3,4-di... Liquid-Crystalline Thiol- and Disulfide-Based Dendrimers for the Functionalization of Gold Nanoparticles [作者：Frein, S; Boudon, J; Vonlanthen, M; Scharf, T; Barbera, J; Suss-Fink, G; Burgi, T; Deschenaux, R,期刊：Helvetica Chimica Acta, 页码：2321-2337 , 文章类型： Article，,卷期：2008年91-12] Liquid-crystalline dendrons carrying either a thiol or disulfide function which display nematic, smectic A, columnar, or chiral nematic phases have been synthesized. Their mesomorphic properties are in agreement with the...