- Asymmetric Total Synthesis of (-)-Leuconoxine via Chiral Phosphoric Acid Catalyzed Desymmetrization of a Prochiral Diester
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The asymmetric total synthesis of (-)-leuconoxine has been achieved. The desymmetrization of a prochiral diester using a chiral phosphoric acid catalyst produced a highly enantioenriched lactam with excellent yield. The ring construction featuring an intr
- Higuchi, Kazuhiro,Suzuki, Shin,Ueda, Reeko,Oshima, Norifumi,Kobayashi, Emiko,Tayu, Masanori,Kawasaki, Tomomi
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- Identification of Diketopiperazine-Containing 2-Anilinobenzamides as Potent Sirtuin 2 (SIRT2)-Selective Inhibitors Targeting the "selectivity Pocket", Substrate-Binding Site, and NAD+-Binding Site
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The NAD+-dependent deacetylase SIRT2 represents an attractive target for drug development. Here, we designed and synthesized drug-like SIRT2-selective inhibitors based on an analysis of the putative binding modes of recently reported SIRT2-selective inhibitors and evaluated their SIRT2-inhibitory activity. This led us to develop a more drug-like diketopiperazine structure as a "hydrogen bond (H-bond) hunter" to target the substrate-binding site of SIRT2. Thioamide 53, a conjugate of diketopiperazine and 2-anilinobenzamide which is expected to occupy the "selectivity pocket" of SIRT2, exhibited potent SIRT2-selective inhibition. Inhibition of SIRT2 by 53 was mediated by the formation of a 53-ADP-ribose conjugate, suggesting that 53 is a mechanism-based inhibitor targeting the "selectivity pocket", substrate-binding site, and NAD+-binding site. Furthermore, 53 showed potent antiproliferative activity toward breast cancer cells and promoted neurite outgrowth of Neuro-2a cells. These findings should pave the way for the discovery of novel therapeutic agents for cancer and neurological disorders.
- Mellini, Paolo,Itoh, Yukihiro,Elboray, Elghareeb E.,Tsumoto, Hiroki,Li, Ying,Suzuki, Miki,Takahashi, Yukari,Tojo, Toshifumi,Kurohara, Takashi,Miyake, Yuka,Miura, Yuri,Kitao, Yuki,Kotoku, Masayuki,Iida, Tetsuya,Suzuki, Takayoshi
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- Exploring of indole derivatives for ESIPT emission: A new ESIPT-based fluorescence skeleton and TD-DFT calculations
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Appropriate synthesis methods gave six different indole derivatives substituted at the C-2 or C-3 position. ESIPT emission capacities of these derivatives were investigated. It was concluded that the indole derivative containing the 1,2-dicarbonyl group at the C-2 position has ESIPT emission. Although adding water to the DMSO solution of the ESIPT-based molecule (9:1) resulted in ESIPT quenching, steady-state measurements in MeOH did not occur ESIPT quenching. TD-DFT calculation for uncovering the ESIPT mechanism emerged that the ESIPT mechanism occurred as a barrierless process. The X-ray analysis and DFT conformational analysis revealed that NH and CO groups involving proton transfer mechanisms are in the cis position. A mono-exponential decay was observed in DMSO and MeOH solutions, in which lifetimes were measured as 6.1 and 5.5 ns, respectively. pH studies revealed that acidic and basic solutions of molecule 7 did not influence ESIPT emission.
- Ayd?n, Hatice Gülten,Ekmekci, Zeynep,Kaya, Serdal,Keskin, Selbi,Menges, Nurettin
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- Visible-Light-Mediated Strategies to Assemble Alkyl 2-Carboxylate-2,3,3-Trisubstituted β-Lactams and 5-Alkoxy-2,2,4-Trisubstituted Furan-3(2H)-ones Using Aryldiazoacetates and Aryldiazoketones
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Two new visible-light-mediated strategies are described starting from aryldiazoacetates. The first approach describes their reaction with azides to afford the corresponding imines, and then reaction with aryldiazoketones produces alkyl 2-carboxylate-2,3,3
- Deflon, Victor M.,Dos Santos, Caio Y.,Gallo, Rafael D. C.,Jurberg, Igor D.,Munaretto, Laiéli S.,Okada, Celso Y.
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supporting information
p. 9292 - 9296
(2021/12/06)
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- N-monoarylacetothioureas as potent urease inhibitors: synthesis, SAR, and biological evaluation
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A urease inhibitor with good in vivo profile is considered as an alternative agent for treating infections caused by urease-producing bacteria such as Helicobacter pylori. Here, we report a series of N-monosubstituted thioureas, which act as effective urease inhibitors with very low cytotoxicity. One compound (b19) was evaluated in detail and shows promising features for further development as an agent to treat H. pylori caused diseases. Excellent values for the inhibition of b19 against both extracted urease and urease in intact cell were observed, which shows IC50 values of 0.16 ± 0.05 and 3.86 ± 0.10 μM, being 170- and 44-fold more potent than the clinically used drug AHA, respectively. Docking simulations suggested that the monosubstituted thiourea moiety penetrates urea binding site. In addition, b19 is a rapid and reversible urease inhibitor, and displays nM affinity to urease with very slow dissociation (koff=1.60 × 10?3 s?1) from the catalytic domain.
- Fang, Hai-Lian,He, Jie-Ling,Li, Wei-Yi,Liu, Shan-Shan,Ni, Wei-Wei,Pan, Xing-Ming,Xiao, Zhu-Ping,Ye, Ya-Xi,Yi, Juan,Zhou, Mi,Zhou, Tian-Li,Zhu, Hai-Liang
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p. 404 - 413
(2020/01/03)
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- Synthesis and SAR of Tetracyclic Inhibitors of Protein Kinase CK2 Derived from Furocarbazole W16
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The serine/threonine kinase CK2 modulates the activity of more than 300 proteins and thus plays a crucial role in various physiological and pathophysiological processes including neurodegenerative disorders of the central nervous system and cancer. The enzymatic activity of CK2 is controlled by the equilibrium between the heterotetrameric holoenzyme CK2α2β2 and its monomeric subunits CK2α and CK2β. A series of analogues of W16 ((3aR,4S,10S,10aS)-4-{[(S)-4-benzyl-2-oxo-1,3-oxazolidin-3-yl]carbonyl}-10-(3,4,5-trimethoxyphenyl)-4,5,10,10a-tetrahydrofuro[3,4-b]carbazole-1,3(3aH)-dione ((+)-3 a)) was prepared in an one-pot, three-component Levy reaction. The stereochemistry of the tetracyclic compounds was analyzed. Additionally, the chemically labile anhydride structure of the furocarbazoles 3 was replaced by a more stable imide (9) and N-methylimide (10) substructure. The enantiomer (?)-3 a (Ki=4.9 μM) of the lead compound (+)-3 a (Ki=31 μM) showed a more than sixfold increased inhibition of the CK2α/CK2β interaction (protein-protein interaction inhibition, PPII) in a microscale thermophoresis (MST) assay. However, (?)-3 a did not show an increased enzyme inhibition of the CK2α2β2 holoenzyme, the CK2α subunit or the mutated CK2α′ C336S subunit in the capillary electrophoresis assay. In the pyrrolocarbazole series, the imide (?)-9 a (Ki=3.6 μM) and the N-methylimide (+)-10 a (Ki=2.8 μM) represent the most promising inhibitors of the CK2α/CK2β interaction. However, neither compound could inhibit enzymatic activity. Unexpectedly, the racemic tetracyclic pyrrolocarbazole (±)-12, with a carboxy moiety in the 4-position, displays the highest CK2α/CK2β interaction inhibition (Ki=1.8 μM) of this series of compounds.
- Borgert, Sebastian,Daniliuc, Constantin G.,Ensan, Deeba,Jose, Joachim,Kr?ger, Lukas,Lauwers, Miriam,Nienberg, Christian,Pietsch, Markus,Steinkrüger, Michaela,Wünsch, Bernhard
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supporting information
p. 871 - 881
(2020/05/06)
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- Novel total syntheses of oxoaporphine alkaloids enabled by mild Cu-catalyzed tandem oxidation/aromatization of 1-Bn-DHIQs
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Novel total syntheses of oxoaporphine alkaloids such as liriodenine, dicentrinone, cassameridine, lysicamine, oxoglaucine and O-methylmoschatoline were developed. The key step of these total syntheses is Cu-catalyzed conversion of 1-benzyl-3,4-dihydro-isoquinolines (1-Bn-DHIQs) to 1-benzoyl-isoquinolines (1-Bz-IQs) via tandem oxidation/aromatization. This novel Cu-catalyzed conversion has been studied in detail, and was successfully used for constructing the 1-Bz-IQ core.
- Zheng, Bo,Qu, Hui-Ya,Meng, Tian-Zhuo,Lu, Xia,Zheng, Jie,He, Yun-Gang,Fan, Qi-Qi,Shi, Xiao-Xin
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p. 28997 - 29007
(2018/08/29)
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- Environmentally Friendly Synthesis of Indoline Derivatives using Flow-Chemistry Techniques
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Flow chemistry proved to be a valuable technique to improve the synthesis route to melanin-concentrating hormone receptor 1 (MCHr1) antagonists with the 1H,2H,3H,4H,5H-[1,4]diazepino[1,7-a]indole scaffold. A one-step route for the heterogeneous catalytic hydrogenation of ethyl 4-(2-nitrophenyl)-3-oxobutanoate for the synthesis of ethyl 2-(2,3-dihydro-1H-indol-2-yl)acetate was developed, and the use of common reducing chemicals was avoided. N-Alkylation of the indoline nitrogen atom was also optimized by using a purpose-built flow reactor and by design of experiment (DoE). Applying an optimal set of parameters allowed us to decrease the amount of carcinogenic 1,2-dibromoethane used by a factor of 10. Additionally, nearly complete conversion was achieved in a fraction of the original reaction time (30 min vs. 4 d); therefore, the productivity (space-time yield) of the flow-reactor system was proven to be ca. 200 times higher than that of the batch process.
- ?rkényi, Róbert,Beke, Gyula,Riethmüller, Eszter,Szakács, Zoltán,Kóti, János,Faigl, Ferenc,éles, János,Greiner, István
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supporting information
p. 6525 - 6532
(2017/12/02)
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- Palladium(II)-catalyzed intramolecular tandem aminoalkylation via divergent C(sp3)-H functionalization
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(Chemical Equation Presented) We have developed a Pd(II)-catalyzed oxidative tandem aminoalkylation via divergent C(sp3)-H functionalization, a ffording three- and five-membered-ring fused indolines in good yields under two optimized conditions, respectively. The mechanism studies have indicated that the benzylic C - H cleavage involved in the former transformation is the rate-determining step, while the cleavage of amide α-C - H in the latter is not. This is the first example of a Pd-catalyzed tandem reaction involving C(sp3)-H activation without the employment of prefunctionalized reagents (e.g., halogenated and boron reagents) and directing groups, representing a green and economic protocol for the construction of N-containing heterocycles.
- Du, Wei,Gu, Qiangshuai,Li, Zhongliang,Yang, Dan
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supporting information
p. 1130 - 1135
(2015/02/05)
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- A new class of "electro-acid/base"-induced reversible methyl ketone colour switches
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Methyl ketone has been designed as a switching unit for electrically addressable molecular colour switches. A newly proposed mechanism of "electro-acid/base" (radical ions)-induced intermolecular proton transfer for the colour switch is proven clearly by cyclic voltammetry (CV), X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (IR) and in situ UV-Vis spectroscopy. A dramatic spectral absorption shift (about 291 nm) is observed during the switching, and blue, yellow and green colours are obtained by adjusting the substituents on the methyl ketone-bridged unit. The in situ "electro-acid/base" is far more convenient than the conventional chemical stimulus of acids or bases for the manipulation of the molecular switching properties. This new switching method and molecular structure manipulation will inspire and accelerate the further development of broad switching materials and applications in ultrathin flexible displays, etc.
- Zhang, Yu-Mo,Li, Minjie,Li, Wen,Huang, Zhiyuan,Zhu, Shaoyin,Yang, Bing,Wang, Xiao-Chun,Zhang, Sean Xiao-An
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p. 5309 - 5314
(2013/09/23)
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- Synthesis and evaluation of boronic acids as inhibitors of Penicillin Binding Proteins of classes A, B and C
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In response to the widespread use of β-lactam antibiotics bacteria have evolved drug resistance mechanisms that include the production of resistant Penicillin Binding Proteins (PBPs). Boronic acids are potent β-lactamase inhibitors and have been shown to display some specificity for soluble transpeptidases and PBPs, but their potential as inhibitors of the latter enzymes is yet to be widely explored. Recently, a (2,6-dimethoxybenzamido) methylboronic acid was identified as being a potent inhibitor of Actinomadura sp. R39 transpeptidase (IC50: 1.3 μM). In this work, we synthesized and studied the potential of a number of acylaminomethylboronic acids as inhibitors of PBPs from different classes. Several derivatives inhibited PBPs of classes A, B and C from penicillin sensitive strains. The (2-nitrobenzamido)methylboronic acid was identified as a good inhibitor of a class A PBP (PBP1b from Streptococcus pneumoniae, IC50 = 26 μM), a class B PBP (PBP2xR6 from Streptococcus pneumoniae, IC50 = 138 μM) and a class C PBP (R39 from Actinomadura sp., IC50 = 0.6 μM). This work opens new avenues towards the development of molecules that inhibit PBPs, and eventually display bactericidal effects, on distinct bacterial species.
- Zervosen, Astrid,Bouillez, Andre,Herman, Alexandre,Amoroso, Ana,Joris, Bernard,Sauvage, Eric,Charlier, Paulette,Luxen, Andre
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experimental part
p. 3915 - 3924
(2012/08/28)
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- Ionic diamine rhodium complex catalyzed reductive N-heterocyclization of 2-nitrovinylarenes
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Ionic diamine rhodium complex (1) catalyzes the reductive N-cyclization of 2-vinylnitroarenes using carbon monoxide as a reducing agent to afford functionalized indoles. The catalytic system allows direct access to indoles with ester and ketone groups at the 2- or 3-position, in good yields.
- Okuro, Kazumi,Gurnham, Joanna,Alper, Howard
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experimental part
p. 4715 - 4720
(2011/07/08)
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- Total synthesis of (±)- and (-)-actinophyllic acid
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Development of efficient sequences for the total syntheses of (±)-actinophyllic acid (rac-1) and (-)-actinophyllic acid (1) are described. The central step in these syntheses is the aza-Cope/Mannich reaction, which constructs the previously unknown hexacyclic ring system of actinophyllic acid in one step from much simpler tetracyclic precursors. The tetracyclic hexahydro-1,5-methano-1H-azocino[4,3-b]indole ketone rac-37 is assembled from o-nitrophenylacetic acid in four steps, with oxidative cyclization of a dienolate derivative of tricyclic precursor rac-35 being the central step. In the first-generation synthesis, this intermediate is transformed in two steps to homoallyl amine rac-43, whose formaldiminium derivative undergoes efficient aza-Cope/Mannich reaction to give pentacyclic ketone rac-44. In four additional steps, this intermediate is advanced to (±)-actinophyllic acid. The synthesis is streamlined by elaborating ketone rac-37 to β-hydroxyester intermediate rac-53, which is directly transformed to (±)-actinophyllic acid upon exposure to HCl and paraformaldehyde. This concise second-generation total synthesis of (±)-actinophyllic acid is realized in 22% overall yield from commercially available di-tert-butyl malonate and o-nitrophenylacetic acid by a sequence that proceeds by way of only six isolated intermediates. The first enantioselective total synthesis of (-)-actinophyllic acid (1) is accomplished by this direct sequence from tricyclic keto malonate (S)-35. Catalytic enantioselective reduction of α,β-unsaturated ketone 66 is the key step in the preparation of intermediate (S)-35 from the commercially available Boc-amino acid 65. Discussed also is the possibility that the aza-Cope/Mannich reaction might be involved in the biosynthesis of (-)-actinophyllic acid.
- Martin, Connor L.,Overman, Larry E.,Rohde, Jason M.
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supporting information; experimental part
p. 4894 - 4906
(2010/06/18)
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- Efficient approaches to S-alkyl-N-alkylisothioureas: Syntheses of histamine H3 antagonist clobenpropit and its analogues
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(Chemical Equation Presented) S-Alkyl-N-alkylisothioureas were efficiently synthesized via synthetic approach (A) using 3-phenylpro-pionyl isothiocyanate (PPI). The utility of the approach was proved by the syntheses of clobenpropit, a potent histamine H3 antagonist, and its analogues. Alternatively, clobenpropit could be prepared via intramolecular amide cleavage (B) with use of 2-nitrophenylacetyl isothiocyanate (NPAI).
- Yoneyama, Hiroki,Shimoda, Ayako,Araki, Lisa,Hatano, Kouta,Sakamoto, Yasuhiko,Kurihara, Takushi,Yamatodani, Atsushi,Harusawa, Shinya
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p. 2096 - 2104
(2008/09/19)
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- Diastereodivergence and appendage diversity in the multicomponent synthesis of aryl-pyrrolo-tetrahydrocarbazoles
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A one-pot approach using a subsequent Cu(II)/Cu(I) catalysis and a highly diastereodivergent three-component reaction allow an easy access to various aryl-pyrrolo-tetrahydrocarbazoles with the control of up to four variable fragments and two different diastereoselectivities.
- Royer, Daniel,Wong, Yung-Sing,Plé, Sophie,Chiaroni, Angèle,Diker, Khalid,Lévy, Jean
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p. 9607 - 9618
(2008/12/22)
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- Total synthesis of (±)-actinophyllic acid
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The first total synthesis of (±)-actinophyllic acid (1) is reported. Key steps of this synthesis include an intramolecular oxidative coupling of ketone and malonic ester enolates and an aza-Cope-Mannich rearrangement that assembled the core structure of t
- Martin, Connor L.,Overman, Larry E.,Rohde, Jason M.
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p. 7568 - 7569
(2008/12/22)
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- PYRAZOLO[3,4-c]QUINOLINES, PYRAZOLO[3,4-c]NAPHTHYRIDINES, ANALOGS THEREOF, AND METHODS
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Pyrazolo[3,4-c]quinolines, pyrazolo[4,5-c]naphthyridines, and analogs thereof, eg., 6,7,8,9-tetrahydro pyrazolo[3,4-c]quinolines, and, pharmaceutical compositions containing the compounds, intermediates, methods of making these compounds, and methods of use of these compounds as immunomodulators, for inhibiting cytokine biosynthesis in animals and in the therapeutic or prophylactic treatment of diseases by inhibiting cytokine biosynthesis are disclosed.
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Page/Page column 64-65
(2008/06/13)
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- Light-activated hydrogel formation via the triggered folding and self-assembly of a designed peptide
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Photopolymerization can be used to construct materials with precise temporal and spatial resolution. Applications such as tissue engineering, drug delivery, the fabrication of microfluidic devices and the preparation of high-density cell arrays employ hyd
- Haines, Lisa A.,Rajagopal, Karthikan,Ozbas, Bulent,Salick, Daphne A.,Pochan, Darrin J.,Schneider, Joel P.
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p. 17025 - 17029
(2007/10/03)
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- FUNGICIDES
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The invention relates to compounds of general formula I, where A, R, Rand Y are as defined in the description; and to their use as phytopathogenic fungicides.
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- Synthesis of pyrazole derivatives 4(1H)-quinolone and 4-chloroquinoline by thermolysis of arylaminomethylene Meldrum's acid derivative
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Efficient syntheses of 4(1H)-quinolone 1 and 4-chloroquinoline 2 by thermolysis of arylaminomethylene Meldrum's acid derivative starting from 2-nitrophenyl acetic acid.
- Peng, Lizeng,Zhang, Tao,Li, Ying,Li, Yulin
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p. 785 - 791
(2007/10/03)
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- New synthetic applications of phenylacetylphenylacetic acids: A divergent synthesis of benzo[a]carbazoles and indolo[2,1-a]isoquinolines
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Here we describe a common access to benzo[a]carbazoles and indolo[2,1- a]isoquinolines from 2'(2'-nitrophenylacetyl)phenylacetic acids.
- Cruces, Jacobo,Estévez, Juan C.,Estévez, Ramón J.,Castedo, Luis
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p. 1041 - 1050
(2007/10/03)
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- Synthesis of aminobenzo[b]pyrrolizinone and aminobenzo[b]indolizinone derivatives
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The fused tricyclic indole derivatives (4a and 4b-1~4b-7) possessing an amino function on the benzo[b]pyrrolizinone or the benzo[b]-indolizinone skeleton were synthesized via intramolecular reductive cyclization and Curtius rearrangement, and these compou
- Taga, Masanao,Ohtsuka, Hisao,Inoue, Isao,Kawaguchi, Takayuki,Nomura, Sumihiro,Yamada, Koichiro,Date, Tadamasa,Hiramatsu, Hajime,Sato, Yasuhiko
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p. 251 - 263
(2007/10/02)
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- SYNTHESE ET REACTIVITE D'OXAZOLOPIPERIDINES ET D'OXAZOLOPIPERIDONES
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The reaction of the oxazolopiperidones 8, 10 (or the oxazolopiperidine 12) which the mixture TMSOTf-TMSCN (or TBDMSOTf-TMSCN) in the presence of ZnBr2, did not lead by irreversible ring opening to the corresponding α-cyanoamides (or α-cyanoamine) as expec
- Alazard. Jean-Pierre,Terrier, Corinne,Mary, Aude,Thal, Claude
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p. 6287 - 6298
(2007/10/02)
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- Intramolecular Diels-Alder Reactions of Pyranoindol-3-ones. Preparation of -Annelated Carbazoles
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The pyranoindol-3-ones (5), readily prepared from t-butyl indole-2-acetate (2) in three steps, undergo facile intramolecular Diels-Alder reaction on heating to give, after loss of carbon dioxide, the -annelated carbazoles (6).
- Moody, Christopher J.,Mprrell, Andrew I.
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p. 309 - 314
(2007/10/02)
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- Orally Active β-Lactam Inhibitors of Leukocyte Elastase-1. Activity of 3,3-Diethyl-2-azetidinones
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A thorough analysis of the mechanism of inhibition of human leukocyte elastase (HLE) by a monocyclic β-lactam and the mechanism of β-lactam hydrolysis led to the preparation of potent and highly stable inhibitors of HLE.This work led to the identification of 4--3,3-diethyl-1-carbonyl>-2-azetidinone (2) as the first orally active inhibitor of human leukocyte elastase (HLE).Analogs of 2 with different substituents on the urea N were synthesized and evaluated for their activity in vitro against HLE as well as in vivo in a hamster lung hemorrhage model.Compounds with a methyl or a methoxy group in the para position of the benzene ring were very potent in both assays.The results are discussed on the basis of the proposed model for the binding of this class of inhibitors to HLE and a possible mechanism of inhibition is presented.
- Shah, Shrenik K.,Dorn, Conrad P.,Finke, Paul E.,Hale, Jeffrey J.,Hagmann, William K.,et al.
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p. 3745 - 3754
(2007/10/02)
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- (1S)-1-(Aminomethyl)-2-(arylacetyl)-1,2,3,4-tetrahydroisoquinoline and heterocycle-condensed tetrahydropyridine derivatives: Members of a novel class of very potent κ opioid analgesics
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The synthesis and structure-activity relationship (SAR) of a novel class of κ opioid analgesics, 1-(amino-methyl)-2-(arylacetyl)-1,2,3,4-tetrahydroisoquinolines and (aminomethyl)-N-(arylacetyl)-4,5,6,7-tetrahydrothienopyridines, are described. These compounds, formally derived by the condensation of a benzene or thiophene ring on the piperidine nucleus of the recently described compounds 1, are from 3 to 7 times more potent as antinociceptive agents and with a longer duration of action than the original lead compounds. A similar N2-C1-C9-N10 pharmacophore torsional angle of approximately 60° was also found for this class of compounds by using X-ray and 1H NMR analyses. The same absolute configuration (S) at the chiral center of the active (-) enantiomers was determined by X-ray crystallographic analysis. A varied degree of κ receptor selectivity was a feature of this novel class of antinociceptive agents (μ/κ ratio from 44 to 950 according to the nature of the basic moiety). A SAR analysis indicated that the presence of electron-withdrawing and lipophilic substituents in para and/or meta positions in the arylacetic moiety and the pyrrolidino or dimethylamino basic groups are required to optimize biological activity. The lead compounds 28, 30, and 48 are among the most potent antinociceptive agents (ED50 ca. 0.020 μM/kg sc) and κ ligands (K(i)(κ) ca. 0.20 nM) identified so far.
- Vecchietti,Clarke,Colle,Giardina,Petrone,Sbacchi
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p. 2624 - 2633
(2007/10/02)
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- Diels-Alder Reactivity of Pyranoindol-3-ones, Indole 2,3-Quinodimethane Analogues
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The pyranoindol-3-ones (7) are stable indole-2,3-quinodimethane type dienes, which undergo Diels-Alder reaction with alkynes to give, after loss of carbon dioxide, carbazoles.The reactivity of the diene is increased by the presence of the electron-withdrawing t-butoxycarbonyl group on the indole nitrogen.The pyranoindolones (7) are less reactive, and exhibit the opposite regiochemistry in their Diels-Alder reactions than the isomeric pyranoindol-3-ones (1).Factors which affect the regiochemistry of the Diels-Alder reaction are discussed.
- Moody, Christopher J.,Rahimtoola, Kulsum F.
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p. 673 - 679
(2007/10/02)
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- Synthesis of Novel Indolobenzodiazepine
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2-benzenamine (15) was prepared in four steps from o-nitrophenylacetic acid, and treated with triethyl orthoformate in an attempt to prepare an oxadiazolobenzodiazepine.However, the resulting product was 13-(5-methyl
- Peet, Norton P.,Sunder, Shyam
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p. 1355 - 1357
(2007/10/02)
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- Ring-Chain Tautomerism in Anions Derived from Substituted (Arylideneamino)toluenes and (Arylideneamino)oxindoles
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Intramolecular nucleophilic attack by carbon and nitrogen anions on imine and enone double bonds, respectively, has been investigated as a synthetic route to fused five-membered azacycles.In both (arylideneamino)toluenes and (arylideneamino)oxindoles, cyc
- Goetz, Frederick J.,Hirsch, Jerry A.,Augustine, Robert L.
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p. 2468 - 2472
(2007/10/02)
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