个性化文献订阅>文章检索

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74条记录   Total Synthesis Without Protecting Groups: Pyrrolidines and Cyclic Carbamates. [作者：Dangerfield, Emma M.;Timmer, Mattie S. M.;Stocker, Bridget L.;,期刊：Organic Letters, 页码：535-538 , 文章类型： 研究论文，,卷期：2009年11-3] A protecting group free synthesis of 2,3-cis substituted hydroxypyrrolidines, e.g. I, is reported. Two novel reaction methodologies allow for the stereoselective formation of cyclic carbamates from olefinic amines, and ... Photoswitchable Sexithiophene-Based Molecular Wires. [作者：Areephong, Jetsuda;Hurenkamp, Johannes H.;Milder, Maaike T. W.;Meetsma, Auke;Herek, Jennifer L.;Browne, Wesley R.;Feringa, Ben L.;,期刊：Organic Letters, 页码：721-724 , 文章类型： 研究论文，,卷期：2009年11-3] Photochromic sexithiophenes were prepd. by oxidative electrochem. coupling of terthiophenes. The redox properties in the open state are typical of sexithiophenes. Ring closure of both photochromic units leads to a decr... "Click, click, cyclize": a DOS approach to sultams utilizing vinyl sulfonamide linchpins. [作者：Zhou, Aihua;Rayabarapu, Dinesh;Hanson, Paul R.;,期刊：Organic Letters, 页码：531-534 , 文章类型： 研究论文，,卷期：2009年11-3] A diversity-oriented synthesis (DOS) strategy termed "Click, Click, Cyclize" is reported. This approach relies on functional group pairing between a vinyl sulfonamide and an array of functional groups to synthesize skel... Efficient Method for the Synthesis of 2,3-Unsubstituted Nitro Containing Indoles from o-Fluoronitrobenzenes. [作者：Liu, Kai;Yin, Dali;,期刊：Organic Letters, 页码：637-639 , 文章类型： 研究论文，,卷期：2009年11-3] A methodol. was developed for the efficient synthesis of 2,3-unsubstituted nitro contg. indoles via acid catalyzed intramol. electrophilic cyclization. Subsequent redn. of nitro groups allows the construction of some in... Substitution on the A-Ring Confers to Bryopyran Analogues the Unique Biological Activity Characteristic of Bryostatins and Distinct From That of the Phorbol Esters. [作者：Keck, Gary E.;Poudel, Yam B.;Welch, Dennie S.;Kraft, Matthew B.;Truong, Anh P.;Stephens, Jeffrey C.;Kedei, Noemi;Lewin, Nancy E.;Blumberg, Peter M.;,期刊：Organic Letters, 页码：593-596 , 文章类型： 研究论文，,卷期：2009年11-3] A close structural analog of bryostatin 1, which differs from bryostatin 1 only by the absence of the C30 carbomethoxy group (on the C13 enoate of the B-ring), has been prepd. by total synthesis. Biol. assays reveal a c... Enantioselective Sequential Conjugate Addition-Allylation Reactions: A Concise Total Synthesis of (+)-Podophyllotoxin. [作者：Wu, Yingming;Zhao, Jingfeng;Chen, Jingbo;Pan, Chengxue;Li, Liang;Zhang, Hongbin;,期刊：Organic Letters, 页码：597-600 , 文章类型： 研究论文，,卷期：2009年11-3] A highly flexible and concise total synthesis of (+)-podophyllotoxin (I) featured with an enantioselective sequential conjugate addn.-allylation reactions was reported. Starting from com. available 3,4,5-trimethoxycinna... First Total Synthesis of a Polyunsaturated Chromone Metabolite Isolated from the Brown Algae Zonaria tournefortii. [作者：Anwar, Hany F.;Hansen, Trond Vidar;,期刊：Organic Letters, 页码：587-588 , 文章类型： 研究论文，,卷期：2009年11-3] The first total synthesis of the marine natural product (all-Z)-5,7-dihydroxy-2-(4,7,10,13,16-nonadecapentaenyl)chromone (I) was achieved in six steps and in 14% overall yield starting from the Et ester of (all-Z)-eicosa... The p-Bromodienone Route to Nucleophilic Functionalization of Calixarene Exo Rim. [作者：Troisi, Francesco;Pierro, Teresa;Gaeta, Carmine;Neri, Placido;,期刊：Organic Letters, 页码：697-700 , 文章类型： 研究论文，,卷期：2009年11-3] Easily accessible calixarene p-bromodienone derivs. undergo a silver-mediated nucleophilic substitution and a subsequent re-aromatization with a range of different O-nucleophiles (alcs. and carboxylates) to give p-alkoxy... Highly cis-Selective Cyclopropanations with Ethyl Diazoacetate Using a Novel Rh(I) Catalyst with a Chelating N-Heterocyclic Iminocarbene Ligand. [作者：Lenes Rosenberg, Marianne;Krivokapic, Alexander;Tilset, Mats;,期刊：Organic Letters, 页码：547-550 , 文章类型： 研究论文，,卷期：2009年11-3] A structurally characterized Rh(I) iminocarbene complex (N,C)Rh(CO)Cl is activated with AgOTf to act as a highly cis-selective catalyst for the cyclopropanation of substituted styrenes and other alkenes with Et diazoacet... Enantioselective organocatalytic Michael addition of malonates to a,b-unsaturated ketones. [作者：Li, Pengfei;Wen, Shigang;Yu, Feng;Liu, Qiaoxia;Li, Wenjun;Wang, Yongcan;Liang, Xinmiao;Ye, Jinxing;,期刊：Organic Letters, 页码：753-756 , 文章类型： 研究论文，,卷期：2009年11-3] A type of primary amine thiourea organocatalysts derived from 1,2-diaminocyclohexane and 9-amino (9-deoxy) cinchona alkaloid was developed into asym. Michael addn. of malonates to enones. A series of cyclic and acyclic ... Nickel-catalyzed oxidative coupling reactions of two different terminal alkynes using O2 as the oxidant at room temperature: facile syntheses of unsymmetric 1,3-diynes. [作者：Yin, Weiyan;He, Chuan;Chen, Mao;Zhang, Heng;Lei, Aiwen;,期刊：Organic Letters, 页码：709-712 , 文章类型： 研究论文，,卷期：2009年11-3] Two different terminal alkynes now can be coupled together in the presence of NiCl2?H2O/CuI by using an excess of one of the terminal alkyne substrates. This method employed 20 mol % TMEDA as the ligand and environmenta... Low Barrier Hydrogenolysis of the Carbon-Heteroatom Bond As Catalyzed by HAlF4. [作者：Zhong, George;Chan, Bun;Radom, Leo;,期刊：Organic Letters, 页码：749-751 , 文章类型： 研究论文，,卷期：2009年11-3] substantially compared with those for the uncatalyzed reactions. For example, the condensed-phase free-energy barrier for the HAlF4-catalyzed hydrogenolysis of CH3-F is about 130 kJ mol-1, compared with 373 kJ mol-1 for... High Ortho Preference in Ni-Catalyzed Cross-Coupling of Halophenols with Alkyl Grignard Reagents. [作者：Wang, Jia-Rui;Manabe, Kei;,期刊：Organic Letters, 页码：741-744 , 文章类型： 研究论文，,卷期：2009年11-3] High preference of substitution at the position ortho to the hydroxy group was obsd. for Ni-catalyzed cross-coupling reactions of dihalophenols with alkyl Grignard reagents. Reactions of 2,4-dihalophenols, with various ... Synthesis and Triplex Formation of Oligonucleotides Containing 8-Thioxodeoxyadenosine. [作者：Miyata, Ken-ichi;Tamamushi, Ryuji;Tsunoda, Hirosuke;Ohkubo, Akihiro;Seio, Kohji;Sekine, Mitsuo;,期刊：Organic Letters, 页码：605-608 , 文章类型： 研究论文，,卷期：2009年11-3] For more effective DNA triplex formation under neutral conditions, we synthesized triplex-forming oligonucleotides contg. 8-thioxodeoxyadenosine (s8dA) residues in place of the protonated deoxycytidines required for the ... Generation of DNA Interstrand Cross-Links by Post-Synthetic Reductive Amination. [作者：Angelov, Todor;Guainazzi, Angelo;Scharer, Orlando D.;,期刊：Organic Letters, 页码：661-664 , 文章类型： 研究论文，,卷期：2009年11-3] DNA interstrand crosslinks (ICLs) are the clin. most relevant adducts formed by many antitumor agents. To facilitate the study of biol. responses triggered by ICLs, we developed a new approach toward the synthesis of mi... Imidazolium-functionalized BINOL as a multifunctional receptor for chromogenic and chiral anion recognition. [作者：Lu, Qiao-Sen;Dong, Liang;Zhang, Ji;Li, Jing;Jiang, Lu;Huang, Yu;Qin, Song;Hu, Chang-Wei;Yu, Xiao-Qi;,期刊：Organic Letters, 页码：669-672 , 文章类型： 研究论文，,卷期：2009年11-3] A novel imidazolium-functionalized BINOL fluorescent receptor I was developed as a multifunctional receptor for both chromogenic and chiral anion recognition. The different fluorescent responses and color changes of I c...