- Stereocontrolled formation of epoxy peroxide functionality appended to a lactam ring
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The action of tert-butyl hydroperoxide and tin(IV) chloride upon allylic alcohols containing a lactam ring leads mainly to epoxy alkyl peroxides with high diastereoselection. Both the stereochemistry and the products formed are in marked contrast to the r
- Marson,Khan,Porter
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- Tin(IV)-mediated stereoselective synthesis of epoxides with concomitant alkyl peroxide formation
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Epoxy alkyl peroxides are formed stereoselectively by the action of t-butyl hydroperoxide-SnCl4 upon allylic alcohols containing an amido group, and with reversal of the diastereoselectivity shown by the action of t-butyl hydroperoxide-VO(acac)2 upon analogous carbocyclic alcohols.
- Hursthouse,Khan,Marson,Porter
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- Double transfer of chirality in organocopper-mediated bis(alkylating) cycloisomerization of enediynes
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An original synthesis of chiral benzofulvenes triggered by organocopper reagents is reported. These enantiopure products are available through a highly chemo-, regio-, diastereo-, and enantioselective bis(alkylating) cycloisomerization process. A double chirality transfer (central-to-axial-to- central) is observed. Double duty: An original synthesis of chiral benzofulvenes was developed through the highly chemo-, regio-, diastereo-, and enantioselective double transfer of alkyl groups to electrophilic enediynes. This organocopper-triggered cycloisomerization proceeds with double transfer of chirality (central-to-axial-to-central).
- Campolo, Damien,Arif, Tanzeel,Borie, Cyril,Mouysset, Dominique,Vanthuyne, Nicolas,Naubron, Jean-Valere,Bertrand, Michele P.,Nechab, Malek
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- α-ACYLIMINIUM ION-ACETYLENE CYCLISATIONS
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Cyclisation of acetylenic ethoxylactams 1b-12b leads to bridgehead nitrogen bicyclic ketones in excellent yields.The reaction is weakly acid-catalysed and proceeds at ambient temperature.The observed regioselectivity effect is discussed in terms of stability of exo vs endo vinyl cations and ring strain effects.The high yield conversion of N-(5-hexynyl)-ethoxy lactams 7b and 8b in the 5/8 and 6/8 fused bicyclic ketolactams 7c and 8c deserves special attention.
- Schoemaker, H. E.,Boer-Terpstra, Tj.,Dijkink, J.,Speckamp, W. N.
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- Synthesis and evaluation of N-heteroarylsubstituted triazolosulfonamides as carbonic anhydrase inhibitors
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A new series of N-heteroarylsubstituted triazolosulfonamide compounds were synthesized and their inhibitory effects on the activity of purified human carbonic anhydrase (hCA) I and II were evaluated. Compounds (3 a-k) were prepared by propargylation of N-heteroaryl compounds. Compound 5 was obtained from sulfanilamide and sodium nitrite followed by addition of sodium azide. The products (6 a-k) were synthesized from compounds 3 and 5. The results showed that all the synthesized compounds were inhibited the CA isoenzymes activity. Figure 6a (IC50 = 0.52 μM for hCA I and 0.34 μM for hCA II) has the most inhibitory effect among the synthesized compounds.
- Balci, Ahmet,Arslan, Mustafa,Nixha, Arleta Rifati,Bilen, Cigdem,Ergun, Adem,Gen?er, Nahit
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- Microwave-assisted N-alkylation of potassium phthalimide and potassium succinimide onto silica gel in dry media
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Synthesis of N-alkyl phthalimides and N-alkyl succinimides through alkylation of potassium phthalimide and potassium succinimide in dry media catalyzed by phase-transfer catalyst under microwave irradiation will be reported. The reactions were with fairly high yield.
- Hekmatshoar,Heravi,Baghernejad,Asadolah
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- Supported copper (I) catalyst from fish bone waste: An efficient, green and reusable catalyst for the click reaction toward N-substituted 1,2,3-TRIAZOLES
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An eco-efficient, green, and multi-gram procedure is presented for one-pot multicomponent synthesis of N-substituted 1,2,3-triazoles by using waste fishbone powders supported CuBr (FBPs-CuBr) as catalyst. FBPs-CuBr is found to be an efficient heterogeneous catalyst and a series of 1,2,3-triazoles are obtained in moderate to excellent yields in water under MW irradiation (70–98%). It can be separated conveniently by a simple filtration and reused at least seven consecutive runs with a slight drop in the product yields. Furthermore, the desired product still could be obtained in 80% yield when the scale of the reaction was increased to 40.0 mmol.
- Xiong, Xingquan,Tang, Zhongke,Sun, Zhaohong,Meng, Xiaoqing,Song, Sida,Quan, Zhilong
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- Chemo- And diastereoselectivities in the electrochemical reduction of maleimides
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The electrochemical cathodic reduction of cyclic imides (maleimides) to succinimides can be achieved chemoselectively in the presence of alkene, alkyne, and benzyl groups. The efficiency of the system was demonstrated by using a 3D electrode in a continuous flow reactor. The reduction of 3,4-dimethylmaleimides to the corresponding succinimides proceeds with a 3:2 diastereomeric ratio, which is independent of the nitrogen substituent and electrode surface area. The stereoselectivity of the process was rationalized by using DFT calculations, involving an acid-catalyzed tautomerization of a half-enol occurring through a double hydrogen-transfer mechanism.
- Rix, Kathryn,Kelsall, Geoffrey H.,Hellgardt, Klaus,Hii, King Kuok
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p. 665 - 671
(2015/03/04)
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- Versatile and sustainable synthesis of cyclic imides from dicarboxylic acids and amines by Nb2O5 as a base-tolerant heterogeneous lewis acid catalyst
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Catalytic condensation of dicarboxylics acid and amines without excess amount of activating reagents is the most atom-efficient but unprecedented synthetic method of cyclic imides. Here we present the first general catalytic method, proceeding selectively and efficiently in the presence of a commercial Nb2O5 as a reusable and base-tolerant heterogeneous Lewis acid catalyst. The method is effective for the direct synthesis of pharmaceutically or industrially important cyclic imides, such as phensuximide, N-hydroxyphthalimide (NHPI), and unsubstituted cyclic imides from dicarboxylic acid or anhydrides with amines, hydroxylamine, or ammonia.
- Ali, Md. Ayub,Siddiki, S. M. A. Hakim,Kon, Kenichi,Hasegawa, Junya,Shimizu, Kenichi
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supporting information
p. 14256 - 14260
(2015/01/09)
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- Palladium catalysed queuing processes. Part 2: Termolecular cyclization-anion capture employing carbon monoxide as a relay switch with in situ generated vinylstannanes
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The palladium catalysed termolecular queuing processes involving aryl iodides, carbon monoxide (1 atm) and in situ generated vinylstannanes as terminating agents afford a variety of complex heterocyclic α,β-unsaturated ketones in good yield.
- Anwar, Usman,Casaschi, Adele,Grigg, Ronald,Sansano, José M
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p. 1361 - 1367
(2007/10/03)
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- Rh(II)-catalyzed asymmetric cyclopropenation of propargyl derivatives; synthesis of cyclopropene- and cis-cyclopropane-amino acids
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The [Rh2{(2S)-mepy}4]-catalyzed cyclopropenation of propargylamines carrying two carboxyl or sulfonyl protecting groups with ethyl diazoacetate proceeds in high yield and with enantioselectivities in the range of 90→97% ee. Selective deprotection of the TEOC-derivative afforded ethyl 2- aminomethylcycloprop-2-ene-1-carboxylate which was converted to several analogs of γ-aminobutyric acid (GABA) containing the cyclopropene or cyclopropane ring.
- Mueller, Paul,Imogai, Hassan
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p. 4419 - 4428
(2007/10/03)
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- N-(4-Amino-2-butynyl)imides
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N-(4-Amino-2-butynyl)imides are prepared from N-propargylimides, paraformaldehyde and the appropriate secondary amine. The compounds are useful as stimulants or depressants of the central nervous system.
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