- Attempts to mimic key bond-forming events associated with the proposed biogenesis of the pentacyclic lamellarins
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The pyrrole-tethered veratroles 16 and 27 each engage in PIFA-induced oxidative cyclization reactions to give compounds 22 and 29, respectively, which incorporate a key tricyclic fragment associated with the title natural products. In contrast, the corresponding catechols 11 and 12 only produce polymeric materials on subjection to analogous reaction conditions. Efforts to study lactone ring formation by the oxidative cyclization of catechol 30 and veratrole 38 have been thwarted by an inability to prepare the former substrate and decomposition of the latter. The reported conversions 44 ? 45 and 46 ? 47 suggest that a C2-carboxy group attached to the pyrrole ring can ?direct' the oxidative cyclization of N-tethered aryl groups. The acquisition of compound 22 by the means described herein provides an adventitious and concise route to the racemic modification of the pyrrolo[2,1-a]isoquinoline alkaloid crispine A (52). CSIRO 2008.
- Axford, Lorraine C.,Holden, Kate E.,Hasse, Katrin,Banwell, Martin G.,Steglich, Wolfgang,Wagler, Joerg,Willis, Anthony C.
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Read Online
- Synthesis and Studies of Potential Inhibitors of CD73 Based on a Triazole Scaffold
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The ecto-5′-nucleotidase CD73 is involved in the production of immunosuppressive adenosine in the tumoral microenvironment and recently became a validated target in immuno-oncology. To avoid formation of CD73-produced adenosine, several series of potential inhibitors of the target enzyme based on a triazole scaffold were synthetized and evaluated on recombinant purified hCD73 and in cell-based assays.
- Braka, Abdenour,Chaloin, Laurent,Cros-Perrial, Emeline,Grosjean, Félix,Jordheim, Lars Petter,Mathé, Christophe,Peyrottes, Suzanne,Uttaro, Jean-Pierre
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supporting information
(2021/12/14)
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- One-pot cascade synthesis of azabicycles via the nitro-Mannich reaction and N -alkylation
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A one-pot, metal-free process for the synthesis of azabicycles is developed. The key transformations involved a cascade of double intramolecular cyclizations via the nitro-Mannich reaction and N-alkylation, providing various ring systems of azabicycles in
- Disadee, Wannaporn,Ruchirawat, Somsak
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supporting information
p. 707 - 711
(2018/02/09)
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- Modular Access to Substituted Azocanes via a Rhodium-Catalyzed Cycloaddition-Fragmentation Strategy
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A short entry to substituted azocanes by a Rh-catalyzed cycloaddition-fragmentation process is described. Specifically, exposure of diverse N-cyclopropylacrylamides to phosphine-ligated cationic Rh(I) catalyst systems under a CO atmosphere enables the directed generation of rhodacyclopentanone intermediates. Subsequent insertion of the alkene component is followed by fragmentation to give the heterocyclic target. Stereochemical studies show, for the first time, that alkene insertion into rhodacyclopentanones can be reversible.
- Shaw, Megan H.,Croft, Rosemary A.,Whittingham, William G.,Bower, John F.
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supporting information
p. 8054 - 8057
(2015/07/15)
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- Synthesis and biological evaluation of isosteric analogs of mandipropamid for the control of oomycete pathogens
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A series of isosteric analogs of mandipropamid were designed and synthesized via 'click chemistry'. The amide bond of mandipropamid was substituted by a 1,2,3-triazole functional group. The bioassay results have indicated that some of the title compounds exhibited moderate fungicidal activity against Pseudoperonospora cubensis, and the activity has been systematically studied as a function of molecular structure. The low activity of the mandipropamid analog that contains a lipid chain is likely due to the presence of a weak hydrogen bond donor in the 1,2,3-triazole. Furthermore, we have performed the molecular modeling and found that N-methylamide could be more effective than amide as the surrogates to 1,2,3-triazole, which ultimately leads to a longer distance (1.1A longer) between the two substitutes in the 1,4-disubstituted 1,2,3-triazole compound.
- Su, Na,Wang, Zhen-Jun,Wang, Li-Zhong,Zhang, Xiao,Dong, Wei-Li,Wang, Hong-Xue,Li, Zheng-Ming,Zhao, Wei-Guang
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experimental part
p. 101 - 111
(2012/06/01)
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- Highly efficient formal synthesis of cephalotaxine, using the stevens rearrangement-acid lactonization sequence as a key transformation
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Cephalotaxine (1), the major alkaloid isolated from Cephalotaxus species, has attracted considerable attention due to the promising antitumor activity of several of its derivatives and its unique structural features. Herein we describe a highly efficient formal synthesis of 1 employing the [2,3]-Stevens rearrangement-acid lactonization sequence as a key transformation from readily available (3,4-dimethoxyphenyl)acetic acid, methyl prolinate, and allyl bromide.
- Sun, Mo-Ran,Lu, Hong-Tao,Wang, Yan-Zhi,Yang, Hua,Liu, Hong-Min
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experimental part
p. 2213 - 2216
(2009/08/07)
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- 2-(4-SUBSTITUTED ALKYL-1-PIPERAZINYL)-2,4,6-CYCLOHEPTATRIEN-1-ONE DERIVATIVES
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2-(4-Substituted alkyl-1-piperazinyl)-2,4,6-cycloheptatrien-1-one derivatives, therapeutically acceptable acid addition salts thereof, processes for their preparation, methods of using the derivatives and pharmaceutical compositions of the derivatives are disclosed. The derivatives exhibit dopamine-receptor stimulating activity in a mammal and are useful for treating hyperprolactinemia, galactorrhea, amenorrhea, impotence, Parkinsonism, diabetes, acromegaly, hypertension and other central nervous system disorders.
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- New selenium-75 labeled radiopharmaceuticals: Selenonium analogues of dopamine
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Selenium-75 labeled selenonium analogues of dopamine, [2-(3,4-dimethoxyphenyl)ethyl]dimethylselenonium iodide (4) and its dihydroxy analogue (7), were prepared by reducing [75Se]selenious acid with sodium borohydride at pH 6.0 and reacting the
- Sadek,Basmadjian,Hsu,Rieger
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p. 947 - 950
(2007/10/02)
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