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1.
Giuliana Righi Emanuela Mandic’ Gaia Clara Mercedes Naponiello Paolo Bovicelli Ilaria Tirotta 《Tetrahedron》2012,68(14):2984-2992
The results obtained from a study on the stereochemical control in the dihydroxylation of the double bond of vinyl epoxides and their derivatives (bromo derivatives, azido derivatives and vinyl aziridines) are presented herein. A significant diastereoselectivity was observed for the bromo derivatives, azido derivatives and N-protected vinyl aziridines, whereas vinyl epoxides and unprotected vinyl aziridines showed no diastereoselectivity. The results obtained are generally consistent with the Kishi model. 相似文献
2.
Functionalized branched aziridines can be prepared in high yields and with high levels of regioselectivity using unprotected aziridines as nitrogen sources in palladium-catalyzed allylic amination. High levels of enantioselectivity can be achieved with BINAP on palladium. This methodology allows for strategic placement of an aziridine-containing fragment within a complex molecule environment for further elaboration. 相似文献
3.
An unprecedented one-pot reaction that allows the synthesis of diprotected amino alcohols from unprotected vinyl aziridines is reported. The results demonstrate the possibility to use various acyl chlorides in order to obtain differently functionalised fragments. Mechanistic insights are given. 相似文献
4.
《Journal of molecular catalysis. A, Chemical》2007,261(1):1-5
A variety of β-hydroxy nitriles and β-amino alcohols have been synthesized by the regioselective ring opening of epoxides and aziridines under neutral and aqueous conditions in the presence of β-cyclodextrin in good yields. 相似文献
5.
One‐Pot Synthesis of Unprotected Anomeric Glycosyl Thiols in Water for Glycan Ligation Reactions with Highly Functionalized Sugars
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M. Sc. Sebastian Köhling Dr. Matthias P. Exner Saba Nojoumi Dr. Jürgen Schiller Prof. Dr. Nediljko Budisa Prof. Dr. Jörg Rademann 《Angewandte Chemie (International ed. in English)》2016,55(50):15510-15514
Chemical synthesis of oligosaccharide conjugates is essential for studying the functional relevance of carbohydrates, and this task would be facilitated considerably if reliable methods for the anomeric ligation of unprotected sugars in water were available. Here, a method for the preparation of anomeric glycosyl thiols from complex unprotected mono‐, di‐, and oligosaccharides is presented. By exploiting the neighboring‐group effect of the 2‐acetamido‐group, 1,2‐oxazolines are generated and converted into 1‐glycosyl thioesters through treatment with 1‐thioacids. The unprotected anomeric glycosyl thiolates released in situ were conjugated to Michael acceptors, aliphatic halogenides, and aziridines to furnish versatile glycoconjugates. Conjugation of amino acids and proteins was accomplished using the thiol–ene reaction with terminal olefins. This method gives efficient access to anomeric glycosyl thiols and thiolates, which enables anomeric ligations of complex unprotected glycans in water. 相似文献
6.
Kenis S D'hooghe M Verniest G Nguyen VD Thi TA Nguyen TV De Kimpe N 《Organic & biomolecular chemistry》2011,9(20):7217-7223
An efficient and straightforward approach towards the synthesis of 1-alkyl-2-(trifluoromethyl)aziridines starting from 1,1,1-trifluoroacetone via imination, α-chlorination, hydride reduction and ring closure was developed. In addition, novel primary β-iodo amines were obtained by regioselective ring opening of these 2-(trifluoromethyl)aziridines using alkyl iodides, and their synthetic potential was demonstrated by converting them into novel α-CF(3)-β-phenylethylamines upon treatment with lithium diphenylcuprate. 相似文献
7.
Yuliya A. Volkova Tamara S. Kuznetsova Nikolai S. Zefirov 《Tetrahedron letters》2010,51(17):2254-2913
A convenient method for the preparation of β-tosylamino nitrates based on the ring-opening reaction of aziridines by tetranitromethane in the presence of triethylamine is described. A series of substituted β-amino nitrates is obtained in high yields under mild conditions. 相似文献
8.
Tim P. Ofman Prof. Dr. Gijsbert A. van der Marel Prof. Dr. Jeroen D. C. Codée Prof. Dr. Hermen S. Overkleeft 《European journal of organic chemistry》2023,26(16):e202300186
Cyclophellitol aziridines have found wide application as mechanism-based, covalent, and irreversible inhibitors of retaining glycosidases. These compounds, like their parent compound, cyclophellitol (a natural product retaining β-glucosidase inactivator), make use of the mechanism of action of retaining glycosidases, which process their substrate through the formation of a transient covalent intermediate. In contrast, inverting glycosidases, the other main family of glycosyl hydrolases, do not employ such a covalent intermediate, and, as a consequence, useful scaffolds for mechanism-based inhibitor design have yet to be discovered. In this work, we explore chemistries that allow for the construction of cyclitol aziridines with the aziridine electrophile attached in an exocyclic fashion, more distal from the anomeric carbon – thus putatively closer to an inverting glycosidase active site nucleophile. The developed chemistries have allowed for the synthesis of a focused library of differently N-substituted, α-and β-glucopyranose configured cyclitol aziridines for future evaluation as inhibitors or inactivators of α-and β-glucosidases alike. 相似文献
9.
Tributylphosphine-catalyzed ring-opening reaction of epoxides and aziridines with acetic anhydride 总被引:1,自引:0,他引:1
Ren-Hua FanXue-Long Hou 《Tetrahedron letters》2003,44(23):4411-4413
Reactions of aziridines and epoxides with acetic anhydride catalyzed by an organophosphine provided the corresponding esters of β-amino alcohols and 1,2-diols in high yields, respectively. 相似文献
10.
An efficient method for the fluoroalkanosulfonyl fluoride-induced cyclodehydration of β-hydroxy sulfonamides and β-hydroxy thioamides to the corresponding aziridines and thiazolines is reported. Mild reaction conditions, operational simplicity, and high yields are the major advantages of this method. 相似文献
11.
A set of chiral β-tellurium amines and their selenium and sulfur-containing derivatives have been efficiently synthesized in good to excellent yields via the ring-opening reaction of chiral aziridines by chalcogen nucleophilic species. 相似文献
12.
Highly regioselective ring opening of epoxides and aziridines using (bromodimethyl)sulfonium bromide
Epoxides and aziridines undergo ring opening efficiently with (bromodimethyl)sulfonium bromide at room temperature to form the corresponding β-bromohydrins and β-bromoamines, respectively. The conversions are highly regioselective and afford the products in excellent yields within a short period of time. 相似文献
13.
We have developed a LiBr catalyzed efficient synthesis of β-amino sulfones from readily available aziridines and sodium sulfinates in good to excellent yields. The synthetic potential of β-amino sulfones has also been demonstrated by their facile conversion to the corresponding vinyl sulfones. The use of water as reaction media, atom-economy and isolation of products by simple filtration in the case of solid β-amino sulfones are certain green virtues of the synthetic protocol. 相似文献
14.
M.Antonietta Loreto Lucio Pellacani Paolo A Tardella Elena Toniato 《Tetrahedron letters》1984,25(38):4271-4274
Ethoxycarbonylnitrene (EtOCON) generated by α-elimination adds cleanly to allylic ethers giving substituted aziridines. Similar addition via nitrenium ion (EtOCONH+) gives derivatives of β-amino alcohols. 相似文献
15.
16.
Epoxides and aziridines are cleaved efficiently and regioselectively in the presence of zirconyl nitrate at room temperature to afford the corresponding β-nitrato-alcohols and -sulfonamides, respectively, in high yields. 相似文献
17.
M. Somi Reddy 《Tetrahedron letters》2005,46(8):1299-1301
NBS has been utilized for the first time for the oxidative cleavage of aryl aziridines involving β-cyclodextrin-aziridine complexes in water to give the corresponding α-amino ketones in high yields. 相似文献
18.
The first example of N-heterocyclic carbene-catalyzed synthesis of β′-amino-α,β-unsaturated ketones via regioselective ring-opening of terminal aziridines with enals is reported. The protocol involves carbonyl umpolung reactivity of enals in which the carbonyl carbon attacks nucleophilically on electrophilic terminal aziridines. No by-product formation, operational simplicity, ambient temperature, good to excellent yields (76-94%), and regioselectivity are the salient features of the present procedure. 相似文献
19.
Deiana L Dziedzic P Zhao GL Vesely J Ibrahem I Rios R Sun J Córdova A 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(28):7904-7917
The development, scope, and application of the highly enantioselective organocatalytic aziridination of α,β-unsaturated aldehydes is presented. The aminocatalytic azirdination of α,β-unsaturated aldehydes enables the asymmetric formation of β-formyl aziridines with up to >19:1 d.r. and 99% ee. The aminocatalytic aziridination of α-monosubstituted enals gives access to terminal α-substituted-α-formyl aziridines in high yields and up to 99% ee. In the case of the organocatalytic aziridination of disubstituted α,β-unsaturated aldehydes, the transformations were highly diastereo- and enantioselective and give nearly enantiomerically pure β-formyl-functionalized aziridine products (99% ee). A highly enantioselective one-pot cascade sequence based on the combination of asymmetric amine and N-heterocyclic carbene catalysis (AHCC) is also disclosed. This one-pot three-component co-catalytic transformation between α,β-unsaturated aldehydes, hydroxylamine derivatives, and alcohols gives the corresponding N-tert-butoxycarbonyl and N-carbobenzyloxy-protected β-amino acid esters with ee values ranging from 92-99%. The mechanisms and stereochemistry of all these catalytic transformations are also discussed. 相似文献
20.
Ring-opening of aziridines with potassium thiocyanate and thiols has efficiently been carried out at room temperature in the presence of sulfated zirconia to give the corresponding β-aminothiocyanates and β-aminosulfides, respectively, in high yields within 2 h and with high regioselectivity. The catalyst, a solid acid, functions under heterogeneous conditions. 相似文献