- An efficient imidation of thioethers with nitrene in water
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The first imidation of thioethers with free nitrene in water was realized. N-Cbz sulfilimines are formed via imidation of thioethers with free nitrene generated from α elimination of nosyloxycarbamates. In this work, water is successfully applied as solve
- Feng, Tao,Luo, Xiaoli,Mo, Junming,Tang, Zhihui
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supporting information
p. 6497 - 6501
(2020/11/10)
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- The enantioselective addition of 1-fluoro-1-nitro(phenylsulfonyl)methane to isatin-derived ketimines
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An asymmetric organocatalytic addition of fluorinated phenylsulfonylnitromethane to isatin-derived ketimines was developed. The reaction was efficiently catalyzed by a chiral tertiary amine, cinchonine. This methodology provides a new type of optically active compound with two adjacent quaternary carbon stereocenters in good yield (up to 96%), with moderate diastereoselectivity (up to 5.7:1 dr) and excellent enantioselectivity (up to 98/96% ee).
- Urban,Franc,Hofmanová,Císa?ová,Vesely
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p. 9071 - 9076
(2017/11/14)
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- ETHYNYLBENZENE DERIVATIVES
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Disclosed are compounds of formulae (I), (II), and (II)I: and pharmaceutically acceptable salts thereof, wherein the variables, R, R1, R2, R3, R101, L, D, Q, Y, X, and Z are defined herein. These compounds are useful for treating Gram-negative bacteria infections.
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Page/Page column 139
(2012/03/26)
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- An efficient one-pot synthesis of azidoformates from alcohols using triphosgene: Synthesis of N-carbobenzyloxy azetidin-2-ones
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An efficient use of triphosgene for the preparation of various azidoformates from alcohols and sodium azide is described. The method is applied to various chiral alcohols including glucose diacetonide to get the corresponding azidoformates. One of these azidoformates has been successfully utilized for the synthesis of N-carbobenzyloxy-β-lactams.
- Patil,Parveen, Ghazala,Gumaste,Bhawal,Deshmukh
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p. 1455 - 1458
(2007/10/03)
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- New versatile fluorinated chiral building blocks: Synthesis and reactivity of optically pure α-(fluoroalkyl)-β-sulfinylenamines
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Efficient synthesis of optically pure α-(fluoroalkyl)-β-sulfinyl enamines has been achieved by aza-Wittig reaction of triphenyliminophosphoranes with the corresponding α-fluorinated-α'-sulfinyl ketones. The title compounds 3,4 showed an overwhelming prefe
- Arnone, Alberto,Bravo, Pierfrancesco,Capelli, Silvia,Fronza, Giovanni,Meille, Stefano V.,Zanda, Matteo,Cavicchio, Giancarlo,Crucianelli, Marcello
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p. 3375 - 3387
(2007/10/03)
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- A convenient synthesis of triphenylphosphine acylimides using N-lithiated triphenylphosphine imide
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A series of triphenylphosphine acylimides and N-(triphenylphosphoranylidene)carbamates have been readily prepared by direct acylation of the N-lithiated triphenylphosphine imide.
- Cristau,Manginot,Torreilles
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p. 382 - 384
(2007/10/02)
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- Formation and Reactions of C-Nitrosoformate Esters, A New Class of Transient Dienophiles
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Oxidation of N-hydroxycarbamic esters, ROCONHOH, with tetraethylammonium or sodium periodate in the presence of conjugated dienes gave N-alkoxycarbonyl-3,6-dihydro-2H-1,2-oxazines, formed apparently by cycloaddition of transient C-nitrosoformate esters, ROCONO, with the dienes.Cleavage of various N-alkoxycarbonyl derivatives under mild conditions is exemplified.The cycloadduct (10a) of benzyl nitrosoformate and 9,10-dimethylanthracene decomposed in benzene at 80 deg C in the presence of thebaine (3) to give the corresponding adduct (4a) of thebaine, together with 9,10-dimethylanthracene.Similarly, the adduct (6b) of 2,2,2-trichloroethyl nitrosoformate and cyclopentadiene, when heated with ergosteryl acetate, gave the corrresponding adduct (8b) of the steroid.Benzyl and t-butyl azidoformates decomposed in dimethyl sulphoxide at 115-130 deg C in the presence of thebaine to give the adducts (4a) and (4c) of benzyl and t-butyl nitrosoformate and the alkaloid.The other, major products were the sulphoximides (20a) and (20c).Alkoxycarbonylnitrenes, therefore, attack dimethyl sulphoxide either on sulphur, to give sulphoximides, or on oxygen, to give nitrosoformates.Benzyl nitrosoformate, generated thermally from either the adduct (10a) or (6a), reacted with triphenylphosphine to give, apparently, benzyloxycarbonylnitrene which attacked the solvent, benzene, to form N-benzyloxycarbonylazepine (24a).The adduct (6c) of t-butyl nitrosoformate and cyclopentadiene behaved likewise to give the azepine (24c).The reaction of (6c) with triphenylphosphine in benzene or dichloromethane gave a small quantity of 5,5-dimethyloxazolidin-2-one (26), a known cyclisation product of t-butyloxy-carbonylnitrene.
- Kirby, Gordon W.,McGuigan, Henry,Mackinnon, John W. M.,McLean, David,Sharma, Ram Prakash
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p. 1437 - 1442
(2007/10/02)
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- PREPARATION OF DI- AND TRIACYLIMINES AND THEIR USE IN THE SYNTHESIS OF NITROGEN HETEROCYCLES
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Reaction of aza-Wittig reagents with glyoxylates and keto malonates produces di- and triacylimines which are moderately reactive dienophiles for Diels-Alder cycloaddition.
- Jung, Michael E.,Shishido, Kozo,Light, Lynn,Davis, Leonard
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p. 4607 - 4610
(2007/10/02)
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