- Visible-Light-Induced Cycloaddition of α-Ketoacylsilanes with Imines: Facile Access to β-Lactams
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We report the synthesis of β-lactams from α-ketoacylsilanes and imines, which proceeds via a formal [2+2] photochemical cycloaddition with in situ generation of siloxyketene. This mild and operationally simple reaction proceeds in an atom-economic fashion with broad substrate scope, including aldimines, ketimines, hydrazones, and fused nitrogen heterocycles, affording a variety of important β-lactams with satisfactory diastereoselectivities in most cases. This reaction also features good functional-group tolerance, facile scalability and product diversification. Experimental and computational studies suggest that α-ketoacylsilanes can serve as photochemical precursors by engaging in a 1,3 silicon shift to the distal carbonyl group.
- Ye, Jian-Heng,Bellotti, Peter,Paulisch, Tiffany O.,Daniliuc, Constantin G.,Glorius, Frank
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supporting information
p. 13671 - 13676
(2021/05/11)
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- A Modular Approach to Dibenzo-fused ?-Lactams: Palladium-Catalyzed Bridging-C?H Activation
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Tricyclic ring systems possessing a dibenzo structure joined to a seven-membered heterocyclic ring frequently show important biological activities. However, a modular approach to these molecules based on efficient intermolecular reaction of readily available chemicals is lacking. Herein, an unprecedented palladium-catalyzed formal [4+3] annulation for modular construction of these tricyclic systems is described. This reaction features easily accessible reactants (o-haloarylaldehydes and N-tosylhydrazones), broad substrate scope, and excellent functional group compatibility. The synthetic potential is demonstrated by the easy scale-up reactions, late-stage modification of complex molecules, and collective synthesis of bioactive molecules and approved drugs.
- Huang, Xueliang,Ma, Liyao,Xia, Jiajin,Xin, Luoting,Yu, Yinghua,Zhu, Lei
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p. 18261 - 18266
(2020/08/21)
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- Synthesis and structure-activity relationship of 2-(aminoalkyl)-2,3,3a,8-tetrahydrodibenzo[c,f]isoxazolo[2,3-a]azepine derivatives: A novel series of 5-HT2A/2C receptor antagonists. Part 1
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The synthesis of a series of novel 2-(aminoalkyl)-2,3,3a,8-tetrahydrodibenzo[c,f]isoxazolo[2,3-a]azepine derivatives as well as their 5-HT2A/2C and H1 receptor binding affinities are described. The in vivo activity as potential anxiolytics of the synthesised compounds was measured in a mCPP challenge test. One of the compounds, 2a, proved to be a potent 5-HT2A/2C receptor antagonist showing as well oral activity and therefore could be considered as a potential anxiolytic/antidepressant agent.
- Andres,Alcazar, Jesus,Alonso, Jose M.,Diaz, Adolfo,Fernandez, Javier,Gil, Pilar,Iturrino, Laura,Matesanz, Encarna,Meert, Theo F.,Megens, Anton,Sipido, Victor K.
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p. 243 - 248
(2007/10/03)
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- Substituted tetracyclic azepine derivatives
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This invention concerns the compounds of formula (I), the pharmaceutically acceptable salts and stereoisomeric forms thereof, and also the N-oxide forms thereof. STR1 wherein: R1 and R2 each independently are hydrogen; C1-6 alkyl; C1-6 alkylcarbonyl; trihalomethylcarbonyl; C1-6 alkyl substituted with hydroxy, C1-6 alkyloxy, carboxyl, C1-6 alkylcarbonyloxy, C1-6 alkyloxycarbonyl or aryl; or R1 and R2 taken together with the nitrogen atom to which they are attached may form a morpholinyl ring or an optionally substituted heterocycle; R3, R4, R5, R6, R9, R10, R11 or R12 each independently are hydrogen, halo, cyano, hydroxy, trifluoromethyl, trifluoromethoxy, carboxyl, nitro, amino, mono- or di(C1-6 alkyl)-amino, C1-6 alkylcarbonylamino, aminosulfonyl, mono- or di(C1-6 alkyl)-aminosulfonyl, C1-6 alkyl, C1-6 alkyloxy, C1-6 alkylcarbonyl, C1-6 alkyloxy-carbonyl; R7 and R8 are each independently hydrogen, hydroxy, C1-6 alkyl, C1-6 alkyloxy or R7 and R8 taken together may form mono- or di(cyano)methylene, or together with the carbon atom to which they are attached form a carbonyl or a spiro substituent; or R7 and R8 taken together may form methylene; R13 is hydrogen, C1-6 alkyl, or trifluoromethyl; R14 is hydrogen, C1-6 alkyl, cyano, or trifluoromethyl; n is zero to 6. These compounds were tested as mCPP-antagonists in rats. The compounds of formula (I) may be used as therapeutic agents in the treatment or the prevention of CNS disorders, cardiovascular disorders or gastrointestinal disorders.
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- Morphanthridines: Part I - Synthesis of 11-Oxomorphanthridine and Morphanthridine (11H-Dibenzazepine)
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A new route has been developed for the synthesis of 11-oxomorphanthridine (IV), starting from N-benzylideneanthranilic acid (III).The schiff base III undergoes cyclization with PPA to give IV which on Wolff-Kishner reduction affords 11H-dibenzazepine
- Sinha, Ashok Kumar,Nizamuddin, S.
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