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Azirine Weinreb amides (N -methoxy- N -methyl-2 H -azirine-2-carboxamides) were synthesized in yields of 35–94 % by the reaction of N , O -dimethylhydroxylamine with 2 H -azirine-2-carbonyl chlorides, formed by the catalytic isomerization of 5-chloroisoxazoles. Red-Al reduction of azirine Weinreb amides affects only the azirine C N bond and leaves the C(O)NMeOMe group unaffected, forming stereoselectively 1-unprotected 3-substituted cis - N -methoxy- N -methylaziridine-2-carboxamides. The developed approach is a stereo-complementary addition to the previously proposed method for preparing unprotected trans - N -methoxy- N -methyl-3-phenylaziridine-2-carboxamide. The Weinreb amide group in the synthesized cis - N -methoxy- N -methylaziridine-2-carboxamides was used to prepare cis -2-acyl-3-arylaziridines by reaction with organometallic compounds. The reaction of organomagnesium compounds with azirine Weinreb amides allow the stereoselective preparation of 3-aryl-3-aryl/hetary/alkyl- N -methoxy- N -methylaziridine-2-carboxamides; which, in turn, were used to obtain the corresponding aziridinyl ketones. The reaction of azirine Weinreb amides with bulky substituents in the 3-position of azirine with organometallic compounds occurs only at the C(O)NMeOMe group with retention of the azirine C N bond with the formation of 2-acyl-2 H -azirines. [Display omitted] • Synthesis of azirine Weinreb amides. • Red-Al reduction of azirine Weinreb amides affects only the azirine C N bond. • Stereoselective approach to 1-unprotected cis - N -MeO- N -Me-aziridine-2-carboxamides. • Preparation of cis -2-acyl-3-arylaziridines and 2-acyl-2 H -azirines. • Stereoselective synthesis of 2-acyl-3-aryl-3-aryl/hetary/alkylaziridines. [ABSTRACT FROM AUTHOR]

The reaction of trimethyl(vinyl)silane 1 and dimethyl(divinyl)silane 2 with various sulfonamides in the oxidative system (tert -BuOCl + NaI) has been studied and shown to be an efficient approach for the synthesis of silylated N-heterocycles. Triflamide demonstrated the reactivity principally different from that of arenesulfonamides. With silane 1 , it afforded the products of iodochlorination and bis(triflamidation) (major), whereas arenesulfonamides gave N-arenesulfonylaziridines in up to 91% yield. Silane 2 with arenesulfonamides yielded the products of mono and bis(iodochlorination), mono and bis(aziridination), and 3,5-diiodo-4,4-dimethyl-1-(arylsulfonyl)-1,4-azasilinanes. By contrast, triflamide, apart from the products of halogenation and iodotriflamidation, unexpectedly gave 3-(trifluoromethylsulfonyl)-5-(triflamido)oxazolidine as the main product. The structure of most heterocyclic products is proved by X-ray analysis. The effect of the silyl group in the substrate and of the substituent in the reagent on the course of oxidative sulfamidation is discussed by comparing with all-carbon analogues. Image 1 • Vinyl silanes undergo via oxidative addition and heterocyclization when reacting with sulfonamides in oxidative conditions. • The reactivity of triflamide is principally different from that of arenesulfonamides. • Silylated mono- and diaziridines, N-sulfonyl-1,4-azasilinanes and 3-(triflyl)-5-(triflamido)oxazolidine are obtained. [ABSTRACT FROM AUTHOR]

Abstract Rhodium(I)-catalyzed intermolecular cycloadditions of alkynes with vinyl aziridines bearing a conjugated carbonyl group in the olefin moiety followed by the double migration resulted in the formation of pyrrole derivatives in a one pot fashion. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

Abstract A series of new optically pure phosphine oxides containing chiral aziridine subunit were synthesized in good yields and applied as organocatalysts in asymmetric Michael reaction of various aliphatic aldehydes with β-nitrostyrene. The corresponding organocatalysts were synthesized starting from optically pure aziridines in a few simple efficient steps. The appropriate Michael adducts were obtained in most cases in very high chemical yield (up to 97%), excellent enantioselectivity (up to 98% of ee) and diastereoselectivity (up to 95:5 of dr). Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

N-Sulfonyloxaziridines are the most commonly used oxaziridines in organic synthesis. Most applications of these stable, commercially available reagents involve the stereo- and regioselective oxidation of nucleophiles which have found many applications in the synthesis of architecturally complex molecules. In addition, these oxaziridines have been used in cycloaddition reactions (oxyamination), epoxidation of alkenes, silyl enol ethers and enamines, as well as C-H oxidation and amination reactions. The object of this review is to highlight recent applications of N-sulfonyloxaziridines in organic synthesis. [ABSTRACT FROM AUTHOR]

A protocol for the synthesis of pyrrolo -p -phenylene-linked porphyrin-fullerene dyads suitable as photoactive materials was developed. The sequence of aziridination – aziridine ring opening – 1,3-dipolar cycloaddition reactions enabled us to provide structural variability both to the porphyrin core and to pyrrole linker, which facilitates designing the electronic structure and morphological parameters of the dyads. The key porphyrin building blocks, nitro-porphyrins, were synthesized by a stochastic cyclocondensation of arenecarbaldehydes with p -nitrophenyl(dipyrrolyl)methane. [ABSTRACT FROM AUTHOR]

Optically pure, chiral imines synthesized from the corresponding aldehydes and 1-(2-aminoalkyl)aziridines in good chemical yields, have been assessed as an NMR chiral shift reagents for effective discrimination of the signals of some acids (mandelic acid and its derivatives and N -protected amino acid). The title compounds have proven to be very useful for the determination of enantiomeric purity and absolute configuration of the aforementioned acid derivatives. [ABSTRACT FROM AUTHOR]

Aziridines are three-membered N-heterocycles that are extremely strained and serve as a significant synthetic intermediate, similar to epoxides, and are found in several bioactive components. The researchers are interested in developing novel synthetic processes for the aziridine moiety in addition to using the currently available methods. The aziridination of alkenes, aided by complexes of transition metals, constitutes an intriguing and exciting synthetic approach. Among various transition metals, iron-catalysed reactions are increasingly prominent due to the biocompatibility and natural abundance of Fe as well as the requirement to develop catalysis that is realistically efficient and enduring for the fine chemical industries. This review highlights the synthesis of aziridines catalysed by an iron catalytic system. [Display omitted] [ABSTRACT FROM AUTHOR]

The novel carba- d , l -allal- and carba- d , l -galactal-derived vinyl N -nosyl aziridines were prepared and the regio- and stereoselective behavior in opening reactions with O - and N -nucleophiles examined. The carbaglycosylating ability of the novel aziridines, as deduced by the amount of 1,4-addition products (1,4-regioselectivity) obtained in the acid-catalyzed methanolysis taken as a model reaction, is similar or superior to that observed with the corresponding carba- d , l -allal- and - d , l -galactal-derived vinyl epoxides, respectively. In all 1,2- and 1,4-addition products obtained, a –( N -nosylamino) group is regio- and stereoselectively introduced at the C(4) carbon of a 1,2- or 2,3-unsaturated carbasugar, susceptible to further elaborations toward aminocyclitol derivatives. The stereoselective synthesis of the corresponding, enantiomerically pure carba- d , l -allal- and - d , l -galactal-derived vinyl N -acetyl aziridines is also described. [ABSTRACT FROM AUTHOR]

The preparation of ( S )-3-methylamino-3-[( R )-pyrrolidin-3-yl]propanenitrile ( 1 ), a key fragment of fluoroquinolone antibiotic PF-00951966 and others was achieved by N -methylative aziridine ring opening, addition of methyl group at the ring nitrogen, and ring-opening via a cyanide nucleophile in a single operation starting from bicyclic ( R )-2-[( R )-pyrrolidine-3-yl]aziridine. The starting compound was elaborated from stereoselective conjugate addition of nitromethane to ( R )-aziridine-2-yl acrylate followed by selective reduction without breaking the aziridine ring. [ABSTRACT FROM AUTHOR]

Novel β-hydroxy-,β-amino- and β-mercapto- dialkyl- and phenyl-alkyl tellurides have been achieved through regioselective ring opening reactions of oxiranes, aziridines and thiiranes with different Te-nucleophiles, including tellurosilanes. Tellurium-125 NMR chemical shifts of selected compounds have been measured. [ABSTRACT FROM AUTHOR]

This account highlights the most relevant transformations of cycloalkane-fused oxiranes and aziridines developed during the past decade with the intention to provide an overview of the ring-opening synthetic techniques towards different functionalized cycloalkanes in racemic or enantiomerically pure form. It focuses also on the regioselectivity/regiocontrol and enantioselectivity of ring-opening methodologies including unsymmetrical cycloalkane-fused oxiranes and aziridines. [ABSTRACT FROM AUTHOR]

An efficient one-pot synthesis of functionalized adamantylaziridines by aza-Michael initiated ring closure (aza-MIRC) reaction of 1-aminoadamantane with α- halogenated Michael acceptors is described. The reaction goes through an aza-Michael intermediate that undergoes an intramolecular nucleophilic substitution. Expectedly, high pressure exerts a beneficial influence in the case of sterically hindered reagents. [ABSTRACT FROM AUTHOR]

2-Methylquinoline promoted room-temperature oxidative ring-opening of N -sulfonyl aziridines with DMSO has been developed, providing a mild and convenient method for the synthesis of a variety of different N -sulfonyl protected α-amino aryl ketones. The employment of 2-methylquinoline was crucial for the success of this mild transformation and good to excellent yields could be achieved. [ABSTRACT FROM AUTHOR]

Functionalized tryptamines are targets of interest for development as small molecule therapeutics. The ring opening of aziridines with indoles is a powerful method for tryptamine synthesis if site selectivity can be controlled. 4-Nitrobenzyl carbamate (PNZ)-protected aziridines undergo regioselective ring opening to produce β-substituted tryptamines for a series of indoles. The PNZ-protected tryptamines can be further manipulated by PNZ removal under mild conditions. [ABSTRACT FROM AUTHOR]

We developed a highly effective organocatalytic system for asymmetric aziridination of cyclic enones. Catalytic asymmetric aziridination of 2-cyclopenten-1-one with t- butyl p -toluenesulfonyloxy carbamate proceeded using 20 mol % of (1 R ,2 R )-1,2-diphenylethylenediamine derivative with an N -4,4-dimethylcyclohexyl group 1h , producing chiral aziridine ketone (1 R ,5 R )- 4 in 82% yield with 99% ee. Organocatalyst 1h was also an effective catalyst for the asymmetric aziridination of other cyclic enones. The obtained chiral aziridine ketone (1 R ,5 R )- 4 could be successfully transformed into the key intermediate for the synthesis of (−)-allosamizoline, demonstrating the utility of this asymmetric aziridination for the synthesis of aminocyclopentitol derivatives. [ABSTRACT FROM AUTHOR]

Synthetic approaches to (1 RS ,2 SR ,6 SR )-7-arylmethyl-2-alkoxymethyl-4,7-diaza-9-oxabicyclo[4.3.0]nonan-8-ones, potentially selective muscarinic M 1 receptor agonists, by hydration of 1,2,5,6-tetrahydropyridines were investigated. 3-Substituted N -tosyl-1,2,5,6-tetrahydropyridines were prepared by ring-closing metathesis (RCM). The direct hydration of these by hydroboration-oxidation was not usefully selective, but cis -3-hydroxymethyl-4- tert -butyldimethylsilyloxy- N -tosylpiperidine was prepared from 3-hydroxymethyl- N -tosyl-1,2,5,6-tetrahydropyridine by epoxidation, mesylation, reductive elimination, silylation and hydroboration-oxidation. Problems were encountered during attempts to prepare 3-alkoxymethyl-1,2,5,6-tetrahydropyridines with protected amino and cyclobutyl substituents at C5 by ring-closing metathesis, perhaps because of steric hindrance. Nevertheless interesting chemistry was encountered during the synthesis of the RCM precursors including a novel coupling via a 2-ethenyl- N -nosylaziridine and the formation of an oxaazathiocin by an intramolecular substitution of the nitro group of an N -nosyl protected amine by a proximate hydroxyl substituent. [ABSTRACT FROM AUTHOR]

A detailed study of tetrathiomolybdate mediated tandem regio- and stereoselective ring opening of aziridine, disulfide formation, reduction of disulfide bond and Michael reaction in a one-pot operation is reported. This constitutes four reactions that take place in one-pot operation. In the reaction of [BnEt 3 N] 4 MoS 4 with an aziridine derived from cyclohexene and in the absence of Michael acceptor intermediates sulfonamidodisulfide and sulfonamidothiol were isolated and fully characterized. It has also been shown that it is possible to carry out selective opening of the aziridine ring in the presence of an epoxide. By incorporating a suitable Michael acceptor as part of the substrate, intramolecular 1,4-addition could be performed, to achieve the synthesis of sulfur containing acyclic, cyclic amino acid ester derivatives and thia-bicyclo[3.3.1]nonane derivatives in good yields. [ABSTRACT FROM AUTHOR]

A new Lewis acid promoted three-component reaction between the aziridine, arene and aldehyde has been developed. This reaction involves sequential ring opening of aziridine and Pictet–Spengler condensation and gives a broad range of cis -1,4-disubstituted tetrahydroisoquinolines in moderate yields with good diastereoselectivities under mild conditions. The methodology provides a rapid and convergent synthesis for the scaffold of tetrahydroisoquinoline and serves as a good tool for constructing the libraries of substituted tetrahydroisoquinolines. [ABSTRACT FROM AUTHOR]

α-Iodoaziridines are unusual motifs and intriguing structures for further functionalisation of the intact aziridine. The preparation of N -protected α-iodoaziridines is achieved through an addition-cyclisation reaction of LiCHI 2 with imines. The effects of varying the N -group and using different carbenoids are investigated. Excellent cis -stereochemistry is achieved, except for N -carbamates containing aryl groups. Using the mixed carbenoid LiCHICl, the iodide leaving group is selected for cyclisation affording chloroaziridines only, as a cis / trans mixture. More convenient and higher yielding conditions for the preparation of alkyl N -Ts α-iodoaziridines are developed, using ClMgCHI 2 . Additionally, the formation of the problematic primary alkyl α-iodoaziridines is achieved. [ABSTRACT FROM AUTHOR]

One-pot synthesis of tryptophanol derivative from N -Boc-aziridine and indole has been developed. The ring opening reaction of the aziridine takes place smoothly at −30 °C in a regioselective manner and tolerates a wide range of functional groups including halogens attached to the aromatic ring, which was also performed on a gram scale. The resulting tryptophanol derivative was converted to (−)-indolactam V from commercially available 4-bromoindole through a copper-mediated aryl amination in nine steps with an overall yield of 32%. [ABSTRACT FROM AUTHOR]

Desymmetrization of meso -aziridines with aromatic thiols was realized by using α-amino acids-derived chiral quaternary phosphonium salts catalysts to provide chiral β-amino sulfides with high yields (up to 99%) and in moderate enantioselectivities (up to 70%). [ABSTRACT FROM AUTHOR]

We report herein the synthesis of various carbanucleoside precursors by a click chemistry approach, employing cyclopent-3-en-1-ylmethanol 1 as starting material. Using aziridine (±)- 2 as key intermediate, we describe an efficient procedure for the synthesis of a series of 3′-deoxy-2′-substituted carbanucleoside precursors, namely aminoalcohols of type (±)- 3 . Alternatively, transformation of alcohol 1 into (3-azido-4-halo-1-cyclopentyl)methanols of type (±)- 4 , allows the preparation of 1,2,3-triazole carbanucleoside analogues of types (±)- 5 and (±)- 8 . [ABSTRACT FROM AUTHOR]

A novel substrate-directed synthetic route to a series of highly functionalized, orthogonally protected di- or triaminocyclopentanecarboxylate derivatives with multiple chiral centres from an unsaturated bicyclic β-lactam has been accomplished by applying stereoselective ring C–C double bond aziridination with chloramine-T and phenyltrimethylammonium tribromide, followed by regioselective aziridine opening with different N,O nucleophiles and hydrides. The functionalization strategy was successfully extended for access to enantiomerically pure orthogonally protected triaminocarboxylates. [ABSTRACT FROM AUTHOR]

The β-hydroxy-α-amino acids (S,S)-allo-threonine, (S,S)-β-hydroxyleucine and a range of aryl substituted (S,S)-β-hydroxyphenylalanines were prepared from the corresponding enantiopure anti-α-hydroxy-β-amino esters via a rearrangement protocol, which proceeds via the intermediacy of the corresponding aziridinium ions. The starting anti-α-hydroxy-β-amino esters were prepared in >99:1 dr using our diastereoselective aminohydroxylation procedure, whereby conjugate addition of lithium (R)-N-benzyl-N-(α-methylbenzyl)amide to an α,β-unsaturated ester is followed by oxidation of the resultant enolate with (-)-camphorsulfonyloxaziridine. Subsequent activation of the hydroxyl group within the anti-α-hydroxy-β-amino esters promoted aziridinium ion formation [which proceeds with inversion of configuration at C(2)], and regioselective ring-opening of the intermediate aziridinium ions with H2O [which proceeds with inversion of configuration at C(3)] gave the corresponding anti-β-hydroxy-α-amino esters as single diastereoisomers (>99:1 dr). Deprotection of these substrates via sequential hydrogenolysis and ester hydrolysis gave the corresponding β-hydroxy-α-amino acids in good yield and high diastereoisomeric and enantiomeric purity. [ABSTRACT FROM AUTHOR]

Abstract: Orthogonally protected azalanthionines were successfully synthesised by the ring-opening of N-activated aziridine-2-carboxylates with protected diaminopropanoic acids (DAPs). The required DAPs were also prepared by ring-opening of N-activated aziridine-2-carboxylates with para-methoxybenzylamine, but it was found that the choice of aziridine protecting groups dictated both the success of the reaction as well as the regioselectivity of the isolated products. Attempts to extend the methodology to the preparation of the more sterically demanding β-methyl azalanthionines have, so far, been unsuccessful. [Copyright &y& Elsevier]

Abstract: The alkylation of indoles by aziridinium ions generated in situ from β-amino chlorides was explored. The outcome of this reaction strongly relied on the substitution pattern of the starting β-amino chloride and requires silver tetrafluoroborate activation to proceed in reasonable yield. Ephedrine- and pseudoephedrine-derived N-cyanomethyl-β-amino chlorides afforded the corresponding tryptamines in a regio- and stereoselective manner and subsequent silver(I)-promoted Pictet–Spengler reactions produced 4-phenyl substituted THBCs in good yields. Unexpected epimerization at C-3 was found in these reactions, producing trans-3,4-disubstituted THBCs stereoselectively. [Copyright &y& Elsevier]

Abstract: A simple and efficient method for the synthesis of 4-hydroxy or 4-alkylamino isoxazolidin-3-ones and 4-hydroxy isoxazolidin-5-ones is described. The synthesis involved the ring opening of ethyl β-arylglycidates or ethyl N-alkylaziridine-2-carboxylates by free N-alkylhydroxylamines or hydroxylamine anions, followed by cyclization to give the title isoxazolidinones in moderate to good yields. [Copyright &y& Elsevier]

Abstract: The Mg-activation of benzal bromide 2b in DMF in the presence of carbonyl compounds 1 or imines 4 leads to epoxides 3 and N-arylaziridines 5, respectively, with acceptable isolated yields. It was found that DMF is likely involved in this process to form a nucleophilic intermediate by reaction with a first generated electrophilic carbene. Results obtained in this chemical approach are compared to those obtained using electrochemical activation, also in DMF. [Copyright &y& Elsevier]

Abstract: Acyl group migration from N to C in aziridine-2-carboxylates takes place in deprotonation reactions and, as a result, aziridine-2,2-dicarboxylates are formed. Mechanistic studies proved that the observed migration is an intramolecular reaction. [Copyright &y& Elsevier]

A reaction of aziridines with fullerene C 60 is shown to provide a stereospecific route to fulleropyrrolidines for a diverse range of substituents. The important limitation of the approach is shown to be the synthesis of N -unsubstituted fulleropyrrolidines, where the imine route described elsewhere suits better. For 2-arylsubstituted fulleropyrrolidines the activation free Gibbs energy, enthalpy and entropy of a hindered aryl group rotation are determined based on the line-shape analysis of temperature dependent NMR spectra. ortho -Fluorophenyl substituted pyrrolofullerenes are shown to have the activation barrier of ca. 16 kcal/mol, which poses these compounds as possible hindered rotors in molecular machines application. [Display omitted] [ABSTRACT FROM AUTHOR]

The synthesis of substituted N -silyloxy aziridines through reaction of silyl nitronates and enol diazo acetates is described. The process involves in situ transformation of enol diazo acetates into donor-acceptor cyclopropenes, their [3 + 2]-cycloaddition with nitronates and subsequent rearrangement of fused isoxazolidine intermediates. Depending on the substrate type, generation of prerequisite cyclopropenes could be promoted by various rhodium carboxylates (acetate, octanoate) in catalysts loadings as low as 50 ppm. Relative configuration of all three stereocenters in aziridine ring was established by NMR techniques and supported by quantum chemical calculations. To create your abstract, type over the instructions in the template box below. Fonts or abstract dimensions should not be changed or altered. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: The ring-opening reaction of 2-trifluoromethyl-N-tosylaziridine with a variety of heteroatom- and carbon-centered nucleophiles was achieved under basic conditions in good to high yield with excellent regioselectivity. These findings enabled an easy access to useful α-trifluoromethyl-N-tosylmethylamine derivatives, such as 1,2-aminoalcohol, 1,2-diamine, 1,2-aminothiol, and distant secondary amine. [Copyright &y& Elsevier]

Abstract: A rapid access to jaspine B and its enantiomer ent-jaspine B from a 2,3-aziridino-γ-lactone is reported. This synthesis relies on a one pot regioselective aziridine ring-opening followed by intramolecular cyclization to install the cis-amino–alcohol pattern of jaspine B and on a modified Julia olefination of the lactone followed by a diastereoselective hydrogenation for the introduction of the C14 aliphatic chain. The separation of enantiomers in the course of this synthesis was achieved by supercritical fluid chromatography. The cytotoxicity of both enantiomers was evaluated. [Copyright &y& Elsevier]

Abstract: The enantioselective ring opening of aziridines using a latent source of HF is described. A combination of two Lewis acids, (salen)Co and an achiral Ti(IV) cocatalyst, provided optimal reactivity and enantioselectivity for the trans β-fluoroamine product. The use of a chelating aziridine protecting group was crucial. Acyclic and cyclic meso N-picolinamide aziridines underwent fluoride ring opening in up to 84% ee, and the kinetic resolution of a piperidine-derived aziridine was performed with k rel=6.6. The picolinamide group may be readily removed without epimerization of the fluoroamine. Preliminary studies revealed a bimetallic mechanism wherein the chiral (salen)Co catalyst delivers the nucleophile and the Ti(IV) cocatalyst activates the aziridine. [Copyright &y& Elsevier]

Abstract: The convenient synthesis of 1,5-diazaspiro[2.3]hexanes, as new structurally challenging strained diazaspirocyclic compounds, was developed starting from easily accessible ethyl 2-(bromomethyl)-1-tosylaziridine-2-carboxylate. The key transformations in the developed four-step sequence involved a chemoselective reduction of the functionalized ethyl 1-tosylaziridine-2-carboxylate to the corresponding β-bromo aldehyde and an aza-Payne-type rearrangement of intermediate N-tosyl 2-(aminomethyl)aziridines into N-alkyl 2-(aminomethyl)aziridines. A final base-mediated cyclization of the formed bromo amines gave efficient access to the new diazaspirocyclic system. [Copyright &y& Elsevier]

Abstract: 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. [Copyright &y& Elsevier]

Abstract: Significant amounts of metal phosphate impurities have been detected by NMR spectroscopy and ICP-OES analysis of synthetic, as well as purchased, samples of VAPOL hydrogen phosphate purified on silica gel. The previously reported VAPOL hydrogen phosphate-catalyzed desymmetrization of meso-aziridines with different silylated compounds, has been re-examined. While metal-free phosphoric acid exhibited low activity and enantioselectivity, calcium and magnesium phosphate salts proved to be the true catalysts in these related processes. Reproducible high enantioselectivities were obtained in the ring-opening of cyclic meso-aziridines with Me3SiX (X=SPh, SePh, N3) employing a 1:1 mixture of calcium and magnesium VAPOL phosphates. The reaction has been successfully extended to Me3SiSBn, Me3SiSMe and Me3SiNCS, giving ring-opened products in high yield and unprecedented moderate to good enantioselectivities. [Copyright &y& Elsevier]

Abstract: The introduction of organoselenium moieties within the structure of carbohydrates has received attention recently. Herein, we report on the synthesis of selenium-containing neoglycoconjugates and pseudodisaccharides by the reaction of nucleophilic selenium species, generated from sugar diselenides, with chiral N-Boc aziridines and sugar tosylates. The reaction proceeds with moderate to good yields for various substrates. The introduction of organoselenium moieties within the framework of various sugars, with increased levels of complexity, thus allowing the synthesis of disaccharide and glycoconjugate mimetics. [Copyright &y& Elsevier]

Abstract: The synthesis of new chiral non-natural seleno-, thio-, and telluro-peptides is described herein. These new compounds were prepared through simple and brief synthetic route, from inexpensive and commercially available amino acids. The products, possessing a highly modular character, were obtained in good to excellent yields (50–96%), via ring opening of aziridines with chalcogenolate anions, generated using indium(I) iodide as a reducing agent. [Copyright &y& Elsevier]

Abstract: Efficient ring opening reaction between aziridines and diphenyl dichalogenides using HCl, Zn° in ionic liquid is disclosed, affording chiral β-chalcogen amines derivatives in good yields under mild reaction condition. The ionic liquid was further reused four times without the loss of its efficiency. The chiral chalcogenoamines showed antimicrobial activity against Gram-positive bacteria strains. [Copyright &y& Elsevier]

Abstract: Highly important trans-3,4-dihydro-2H-1,4-benzoxazine moieties were easily synthesized by domino aziridine ring opening with o-bromophenols and o-chlorophenols followed by the palladium catalyzed coupling-cyclization (intramolecular C(aryl)–N(amide) bond formation) with good to excellent yields. [Copyright &y& Elsevier]

Abstract: A series of fluorinated N-aminoaziridines have been synthesized by the PhI(OAc)2-mediated aziridination procedure. The reaction was carried out with various protected hydrazides and fluorinated alkenes. The reaction was extended to alkenes bearing an amino acid and the ring opening of the CF3–N-aminoaziridines has been investigated. [Copyright &y& Elsevier]

Abstract: The reaction of fused ring aziridines, 3-oxa-1-azabicyclo[3.1.0]hexan-2-ones, with amine nucleophiles can provide either an aminomethyl oxazolidinone or an aziridinyl urea. The amine, reaction solvent, and aziridine substitution have been examined with the aid of computational studies to identify reaction conditions that provide a single product. Polar solvents provided only the aminomethyl oxazolidinone products. Formation of aziridinyl ureas required control of aziridine substitution, solvent, and reactant stoichiometry. [Copyright &y& Elsevier]

Abstract: A Cu(I)-catalyzed asymmetric aziridination of styrenes with a chiral N-tosyloxycarbamate has been developed. Double stereodifferentiation was observed and both the N-tosyloxycarbamate substituent and the bis(oxazoline) ligand have a significant effect on the yields and diastereoselectivities. The best results for the aziridination were obtained with electron-deficient styrenes. Subsequent ring-opening reactions of styrene-derived aziridines at the benzylic position were observed with various oxygen and nitrogen nucleophiles under Lewis acid catalysis affording the corresponding products with complete inversion of stereochemistry. The strategy was used to synthesize the β-blocker, (R)-nifenalol. [Copyright &y& Elsevier]

Abstract: 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. [Copyright &y& Elsevier]

Abstract: Preparation of functionalized 3,4-dihydroisoquinolines 17a–j from (S)-N-methoxy-N-methyl-1-[(R)-1-phenylethyl]aziridine-2-carboxamide 4 is an effective route for the synthesis of 3-(hydroxymethyl)-1,2,3,4-tetrahydroisoquinolin-4-ols. Stereoselective reduction of the cyclic imines 17a–j resulted in (1S,3S,4R)-4-(tert-butyldimethylsilyl-oxy)-3-[(tert-butyldimethylsilyloxy)methyl]-6,7-dimethoxy-1,2-disubstituted-1,2,3,4-tetrahydroisoquinolines and the desilylation of the TBS groups afforded (1S,3S,4R)-3-(hydroxymethyl)-6,7-dimethoxy-1,2-disubstituted-1,2,3,4-tetrahydroisoquinolin-4-ols 19a–i in good yields. Also, an asymmetric synthesis of novel tetracyclic 3-(hydroxymethyl)-1,2,3,4-tetrahydroisoquinolin-4-ols 23 and 25 was successfully achieved via Pd-catalyzed N-arylation and C–C coupling reaction. [Copyright &y& Elsevier]

Abstract: In this work, cis-2,5-disubstitutedoxazolidines were efficiently constructed via a regioselective C–C bond cleavage of N-tosylaziridine 2,2-dicaboxylates and a subsequent [3+2] cycloaddition with aromatic aldehydes in the presence of Zn(OTf)2. The reactions were highly diastereoselective to form oxazolidines in cis configurations. trans-2,5-Disubstituted imidazolidines were also diastereoselectively synthesized in the similar manner using imines as substrates and AgOTf as catalyst. Based on the detailed investigation of the substrate diversity for both reactions, including the electronic effects and the steric effects of the substituted groups on the aziridines, aldehydes, and imines, a stepwise mechanism was postulated for the diastereoselective formation of cis-2,5-disubstitutedoxazolidines and trans-2,5-disubstituted imidazolines. [Copyright &y& Elsevier]

Abstract: ‘Gear-like’ rotations of simple C–C bonds have been observed in some aziridine methanol derivatives. These restricted rotations have been studied by dynamic and multinuclear magnetic resonance experiments, and the barrier for rotations of Csp3–Csp3 and Csp3–Csp2 bonds have been calculated. The role of an intramolecular hydrogen bond on the stereodynamics has also been demonstrated. [Copyright &y& Elsevier]