Protonenresonanz‐Untersuchungen zur Inversion am dreibindigen Stickstoffatom, I Der Diaziridin‐Ring als Asymmetriezentrum

Mannschreck, Albrecht; Radeglia, R.; Gründemann, E.; Ohme, R.

doi:10.1002/cber.19671000603

Cited by 94 publications

(16 citation statements)

References 16 publications

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“…First of all, diaziridines are among a few matters that contain nitrogen atoms which are configuration-stable under trivial conditions (inversion barriers 20-27 kcal/mol), and, consequently, these compounds have been extensively used to investigate stereochemistry of nitrogen. 10,11 This side of diaziridine chemistry was studied basically by Prof.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of monocyclic diaziridines and their fused derivatives

Махова¹,

Petukhova²,

Кузнецов³

2008

Arkivoc

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Diaziridines and their fused analogues have a wide-range potential as a test subjects for theoretical and practical application. This review covers our investigations focused on the development of optimal methods for the synthesis of monocyclic and fused diaziridine derivatives. Several approaches to the preparation of monocyclic diaziridine derivatives were developed: (1) a synthesis of 3,3-di-and 1,3,3-trialkylmono-and α,ω-bis(diaziridin-1-yl)alkanes from ketoxime O-sulfonates and ammonia, and primary aliphatic amines, respectively, as well as of practically previously inaccessible 3-monoalkyldiaziridines from ammonium salts of aldoxime O-sulfonic acids and ammonia (2) a synthesis of diaziridines from carbonyl compounds, primary aliphatic amines, and aminating reagents in water (or a water-MeOH mixture) at controlled pH of the medium, as well as from carbonyl compounds, amines and N-chloroalkylamines in aprotic solvents in the presence of K 2 CO 3, and (3) a synthesis of 1,2,3-trialkyldiaziridines from Nchloroalkylamines without carbonyl compounds in the presence of primary aliphatic amines at high pressure. As regards fused diaziridine derivatives, general and simple methods were developed to prepare four types of these structures: 1,5-diazabicyclo[3.1.0]hexanes, 1,6-diazabicyclo[4.1.0]heptanes, 1,3,5-triazabicyclo[3.1.0] hexanes, including the parent compound and 2,4-nonsubstituted structures, and 1,3,6-triazabicyclo[3.1.0]hexanes, the latter being previously unknown. The diastereomers have been isolated for 3,3′-bi-and 1,1′-alkylenebisdiaziridines. As a whole the investigations performed in our laboratory have resulted in the simple and general methods for preparing any kind of monocyclic and fused diaziridine derivatives that give high opportunities in the study of their chemical and stereochemical properties, and applications.

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Section: Introductionmentioning

confidence: 99%

Synthesis of monocyclic diaziridines and their fused derivatives

Махова¹,

Petukhova²,

Кузнецов³

2008

Arkivoc

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“…4,5 Diaziridines are proved to be unique chemical objects as: (1) They possess nitrogen atoms which are configuration-stable under trivial conditions (inversion barriers 20-27 kcal/mol), and consequently, have been extensively applied to investigate stereochemistry of nitrogen. [6][7][8] (2) Diaziridine derivatives are also of interest as neurotropically active compounds.…”

Section: Introductionmentioning

confidence: 99%

New Insights on the Mechanism of Thermal Cleavage of Unsaturated Bicyclic Diaziridines: A DFT Study

et al. 2011

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A DFT calculations are carried out at UB3LYP/6-311＋＋G (3df, 2p) levels of theory to study electrocyclic thermal cleavage of four (R) derivatives of unsaturated bicyclic diaziridines, 1 X-R , to produce corresponding (Z) and (E) azomethine imides (2 X-Z , 2 X-E , 3 X-Z and 3 X-E ), where X＝H, Me, t-Bu and Ph. Cleavage of 1 X-R series to form the most stable 3 X-Z product, (path 2) is found the favored procedure because of delocalized negative charge on five atoms and lower steric effect in related transition state. According to IRC calculations in paths 1 and 2, C 6 -N 1 bond is cleaved before the rate determinating step (transition state). The stability of unsaturated bicyclic diaziridines and their corresponding (Z) and (E) azomethine imides is in the following order in gas phase and chloroform, tetrahydrofuran, and acetone solvents: 3 X-Z ＜3 X-E ＜2 X-Z ＜2 X-E ＜1 X-R ＜1 X-S .

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“…In the case of strong electron withdrawing substituent, like fluoro or alkoxy groups, the energy barriers jump to over 120 kJ mol –1 , making it possible to resolve racemates at room temperature. Also, oxaziridines and 1,2‐dialkyldiaziridines, in which the nitrogen chiral center is connected to an endocyclic heteroatom, display high barriers to inversion. In the case of cyclic 1,2‐dialkyl‐hydrazines, the steric compression between adjacent bulky substituents on nitrogen atoms during the inversion makes it possible to induce slow NPI in larger rings like 1,2‐di‐ tert ‐butyl‐diazetidine, and 1,3,4‐oxadiazolidines, even though intrinsic ring strain becomes negligible in the latter case.…”

Section: Introductionmentioning

confidence: 99%

Stereodynamics of Nitrogen Chiral Centers in aza‐β³‐Cyclodipeptides

et al. 2013

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The present work is devoted to the synthesis, conformational analysis, and stereodynamic study of aza-β(3)-cyclodipeptides. This pseudopeptidic ring shows E/Z hydrazide bond isomerism, eight-membered ring conformation, and chirotopic nitrogen atoms, all of which are elements that are prone to modulate the ring shape. The (E,E) twist boat conformation observed in the solid state by X-ray diffraction is also the ground conformation in solution, and emerges as the lowest in energy when using quantum chemical calculations. The relative configuration associated with ring chirality and with the two nitrogen chiral centers is governed by steric crowding and adopts the (P)S(N) S(N)/(M)R(N)R(N) combination which projects side chains in equatorial position. The nitrogen pyramidal inversion (NPI) at the two chiral centers is correlated with the ring reversal. The process is significantly hindered as was shown by VT-NMR experiments run in C2D2Cl4, which did not make it possible to determine the barrier to inversion. Finally, these findings make it conceivable to resolve enantiomers of aza-β(3)-cyclodipeptides by modulating the backbone decoration appropriately.

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Protonenresonanz‐Untersuchungen zur Inversion am dreibindigen Stickstoffatom, I Der Diaziridin‐Ring als Asymmetriezentrum

Cited by 94 publications

References 16 publications

Synthesis of monocyclic diaziridines and their fused derivatives

Synthesis of monocyclic diaziridines and their fused derivatives

New Insights on the Mechanism of Thermal Cleavage of Unsaturated Bicyclic Diaziridines: A DFT Study

Stereodynamics of Nitrogen Chiral Centers in aza‐β³‐Cyclodipeptides

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Protonenresonanz‐Untersuchungen zur Inversion am dreibindigen Stickstoffatom, I Der Diaziridin‐Ring als Asymmetriezentrum

Cited by 94 publications

References 16 publications

Synthesis of monocyclic diaziridines and their fused derivatives

Synthesis of monocyclic diaziridines and their fused derivatives

New Insights on the Mechanism of Thermal Cleavage of Unsaturated Bicyclic Diaziridines: A DFT Study

Stereodynamics of Nitrogen Chiral Centers in aza‐β3‐Cyclodipeptides

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Stereodynamics of Nitrogen Chiral Centers in aza‐β³‐Cyclodipeptides