- Synthesis and structure-activity relationship of disubstituted benzamides as a novel class of antimalarial agents
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Malaria is a devastating world health problem. Using a compound library screening approach, we identified a novel series of disubstituted benzamide compounds with significant activity against malaria strains 3D7 and K1. These compounds represent a new antimalarial molecular scaffold exemplified by compound 1, which demonstrated EC50 values of 60 and 430 nM against strains 3D7 and K1, respectively. Herein we report our findings on the efficient synthesis, structure-activity relationships, and biological activity of this new class of antimalarial agents.
- Mitachi, Katsuhiko,Salinas, Yandira G.,Connelly, Michele,Jensen, Nicholas,Ling, Taotao,Rivas, Fatima
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supporting information; scheme or table
p. 4536 - 4539
(2012/08/07)
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- Synthesis and biological evaluation of 3-alkyl-dihydrotetrabenazine derivatives as vesicular monoamine transporter-2 (VMAT2) ligands
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In the search of new probes for in vivo brain imaging of vesicular monoamine transporter type 2 (VMAT2), we have developed an efficient synthesis of a novel series of 3-alkyl-dihydrotetrabenazine (DTBZ) derivatives. The affinity of VMAT2 was evaluated by an in vitro inhibitory binding assay using [125I]-iodovinyl-TBZ or [18F](+)-FP-DTBZ as radioligands in rat striatal tissue homogenates. New DTBZ derivatives exhibited moderate to good binding affinity to VMAT2. Among these new ligands, compound 4b showed the best affinity for VMAT2 (Ki = 5.98 nM) and may be a useful lead compound for future structure-activity studies.
- Zheng, Pinguan,Lieberman, Brian P.,Choi, Seok Rye,Pl?essl, Karl,Kung, Hank F.
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supporting information; scheme or table
p. 3435 - 3438
(2011/06/24)
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- Diverse asymmetric quinolizidine synthesis: A stereodivergent one-pot approach
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A diverse stereodivergent organocatalytic one-pot addition/cyclization/ annulation sequence to optically active quinolizidine derivatives from easily available starting materials is presented. The one-pot sequence relies on a pyrrolidine-catalyzed enantioselective conjugate addition of electron-deficient amide a-carbons to α,β-unsaturated aldehydes, spontaneous hemiaminal formation and acid-catalyzed/mediated N-acyliminium ion cyclization to give the quinolizidine framework. Simple tuning of the reaction conditions in the N-acyliminuim ion cyclization step provides a diastereomeric switch, which gives access to both of the two bridgehead epimers through kinetic, thermodynamic or chelation control. The methodology display a broad substrate scope that is demonstrated by the stereoselective formation of indolo-, thieno-, benzofuro-, furo- and different benzoquinolizidine derivatives with high atom efficiency, up to >99% ee and up to >95:5 dr. Due to its efficiency, synthetic diversity and operational simplicity, this protocol has the potential to find important use as a key step in natural product synthesis, biochemistry and pharmaceutical science. The stereochemical outcome of the one-pot sequence was investigated, and the mechanism and origin of stereoselectivity of the different steps is discussed.
- Zhanga, Wei,Franzena, Johan
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supporting information; experimental part
p. 499 - 518
(2010/06/17)
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- Enantioselective total syntheses of the Ipecacuanha alkaloid emetine, the Alangium alkaloid tubulosine and a novel benzoqainolizidine alkaloid by using a domino process
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The first enantioselective syntheses of the Ipecacuanha alkaloid emetine (1) and the Alangium alkaloid tubulosine (2) is described employing a domino Knoevenagel/hetero-Diels-Alder reaction and an enantioselective catalytic transfer hydrogenation of imines as key steps. Thus, hydrogenation of the imine 15 with the catalyst (R,R)-16 gives the tetrahydroisoquinoline 14 with 95% ee which was transformed into the aldehyde (1S)-7. The three-component domino reaction of (1S)-7 with 6 and 8 led to 19, which in a second domino process was treated with K2CO3 in methanol followed by a hydrogenation to give the benzoquinolizidine 4 together with the diastereomers 22 and 23 in a overall yield of 66%. Further transformation of 4 with the amines 3 and 5 yielded enantiopure emetine (1) and tubulosine (2), respectively. In addition, starting from 19 the novel benzoquinolizidine alkaloid 34 was synthesised; this compound resembles the vallesiachotamine alkaloid dihydroantirhin 31, which has not been isolated so far but probably must also exist in nature.
- Tietze, Lutz F.,Rackelmann, Nils,Mueller
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p. 2722 - 2731
(2007/10/03)
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- Pyrrolo (2.1a)dihydroisoquinolines and their use as phosphodiesterase 10a inhibitors
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The present invention relates to pyrrolo[2.1-a]dihydroisoquinolines which are inhibitors of phosphodiesterase 10a and can be used for combating cancer.
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- Pyrrolo[2.1-a]isoquinoline derivatives
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The present invention relates to pyrrolo[2.1-a]isoquinolines which are inhibitors of phosphodiesterase 10a, a process for preparing these compounds and a method of treating cancer in humans and animals by administering these compounds.
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- Aza-annulation as a versatile approach to the synthesis of non-benzodiazepene compounds for the treatment of sleep disorders
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The aza-annulation of enamino ester substrates has been demonstrated as an efficient alternative to the syntheses of non-benzodiazepine sleep inducers. Enamino ester substrates derived from aryl, thiophene, and indole functionally were prepared from the c
- Benovsky, Petr,Stille, John R.
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p. 8475 - 8478
(2007/10/03)
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- REGIO- AND STEREO-CONTROLLED DIELS-ALDER REACTION OF DIOXOPYRROLINES WITH ACTIVATED BUTADIENES: FACILE SYNTHESES OF RING D FUNCTIONALIZED ERYTHRINANS
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Diels-Alder reaction of Δ2-pyrroline-4,5-diones with activated butadienes proceeds in regio- and stereo-selective manner.Thus, isoquinolinopyrrolinediones (prepared in 3 steps from β-arylethylamines) gave single erythrinan derivatives which are
- Sano, Takehiro,Toda, Jun,Kashiwaba, Noriaki,Tsuda, Yoshisuke,Iitaka, Yoichi
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p. 1151 - 1156
(2007/10/02)
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