α- vs Ortho-Lithiation ofN-Alkylarylaziridines: Probing the Role of the Nitrogen Inversion Process†

2008 ◽  
Vol 73 (23) ◽  
pp. 9214-9220 ◽  
Author(s):  
Francesco Affortunato ◽  
Saverio Florio ◽  
Renzo Luisi ◽  
Biagia Musio
Keyword(s):  
Inversion Process ◽  
Nitrogen Inversion

scholarly journals A study of nitrogen inversion process in some camphor-based isoxazolidines

ARKIVOC ◽  
2008 ◽  
Vol 2008 (16) ◽  
pp. 255-267
Author(s):  
Shaikh A. Ali ◽  
M. I. M. Wazeer ◽  
M. B. Fettouhi ◽  
M. Z. N. Iman
Keyword(s):  
Inversion Process ◽  
Nitrogen Inversion

Rate-Determining Role of Strain for Nitrogen Inversion in Polycyclic Tertiary Amines1

1996 ◽  
Vol 118 (33) ◽  
pp. 7783-7789 ◽  
Author(s):  
Anatoly M. Belostotskii ◽  
Hugo E. Gottlieb ◽  
Alfred Hassner
Keyword(s):  
Nitrogen Inversion

The Synthesis and Properties of Dimethyl 1,2-Diazetine-1,2-dicarboxylate, a Potentially Aromatic Molecule

1979 ◽  
Vol 32 (12) ◽  
pp. 2659 ◽  
Author(s):  
RN Warrener ◽  
EE Nunn ◽  
MN Paddon-Row
Keyword(s):  
Ring Opening ◽  
Energy Surface ◽  
Alder Reaction ◽  
Diels Alder ◽  
Inversion Process ◽  
Nitrogen Inversion ◽  
Aromatic Character ◽  
Diels Alder Reaction ◽  
Planar Form ◽  
High Stereoselectivity

The cyclobutene n-bond of dimethyl 2,3-diazabicyclo[2,2,0]hex-5-ene-cis-2,3-dicarboxylate (15) has been employed as a dienophile in the Diels-Alder reaction with 2,5-dimethyl-3,4-diphenylcyclopenta- 2,4-dienone (17). The reaction occurred with high stereoselectivity and led, almost exclusively, to the formation of the exo-fused adduct (18). A similar cycloaddition was performed between the dienone (17) and the bicyclo[2,2,0]hex-5-ene-cis-2,3-dicarboxylic anhydride (5) to yield a 90 : 10 mixture of adducts (6). These several adducts were used as precursors for the preparation of the related bicyclo[4,2,0]octa-2,4-diene derivatives (7) and (20), themselves used as photosubstrates for the 1,2-photoaromatization reaction. In this way the carbocyclic precursor (7) yielded cyclobut-3- ene-cis-1,2-dicarboxylic anhydride (8), and the hetero analogue (20) yielded the title diazetine (21). Hydrogenation of this heterocycle yielded the related 1,2-diazetidine (22) which was fully characterized. The reactivity of the diazetine, which formally contains six delocalized electrons, is considered especially as it relates to its potential aromatic character. In practice the facile ring- opening of the diazetine to the 1,4-diazabuta-1,3-diene (23) fairly reflects the lack of aromaticity of this ring system. An INDO MO SCF method has been used to evaluate the energetics of the nitrogen inversion process in the unsubstituted 1,2-diazetine ring. The results indicate that the planar form lies at a maximum on the energy surface and that there is little electron delocalization. The planar form is best described as being antiaromatic. PMO arguments are presented which support this conclusion.

Six-Membered Cyclic Nitroso Acetals: Synthesis and Studies of the Nitrogen Inversion Process ofN-Silyloxy-3,6-dihydro-2H-1,2-oxazines

2016 ◽  
Vol 2016 (33) ◽  
pp. 5569-5578 ◽  
Author(s):  
Alexander S. Shved ◽  
Andrey A. Tabolin ◽  
Roman A. Novikov ◽  
Yulia V. Nelyubina ◽  
Vladimir P. Timofeev ◽  
...  
Keyword(s):  
Inversion Process ◽  
Nitrogen Inversion

A molecular orbital study of the conformation (inversion and rotational barriers) and electronic properties of sulfamide

1989 ◽  
Vol 67 (12) ◽  
pp. 2227-2236 ◽  
Author(s):  
Otilia Mó ◽  
José L. G. De Paz ◽  
Manuel Yáñez ◽  
Ibon Alkorta ◽  
José Elguero ◽  
...  
Keyword(s):  
Multiple Bond ◽  
Amino Groups ◽  
Orbital Exponent ◽  
Nitrogen Inversion ◽  
Rotational Barriers ◽  
Polarization Functions ◽  
D Orbitals ◽  
Bond Character ◽  
Abinitio Calculations

Abinitio calculations have been used to study the conformational potential surface of sulfamide, by considering the S—N bond rotations and the nitrogen inversion processes. The lowest energy conformation (b) is found for a cis–trans arrangement of the amino groups, although conformations with cis–cis (a), trans–trans (c), and near staggered (c′) arrangements lie close in energy. Nitrogen inversion barriers are very low, and consequently one may expect forms b and c′ to be the only ones present in the gas phase. Conformer a is very polar, its dipole moment being twice that of b, so it may be favored in condensed media or in polar-solvent solutions. The relative stability of the different isomers is governed by interactions between the amino protons and between the nitrogen lone pairs. Our results show that d–π backbonding, involving the d orbitals on sulfur, is responsible for the multiple bond character of the S—O linkage, but is very small in the S—N interactions. The role of the sulfur d-orbital exponent, when a 6-31G* basis is used, is analyzed on a series of model compounds containing SII, SIV, and SVI. Although the inclusion of d functions on sulfur is crucial to describing correctly the bonding in sulfamide, the results obtained do not change appreciably if a second set of d functions is centered on sulfur. Nevertheless, only when polarization functions are also included for first-row atoms is the description of the system reliable. Keywords: sulfamide, inversion and rotational barriers, sulfur d-functions.

Conformational assignments and a nitrogen inversion process in some 3-acyloxy-1,3-oxazinanes by NMR and X-ray analysis

1999 ◽  
pp. 877-884 ◽  
Author(s):  
Syed M. A. Hashmi ◽  
Mohammed I. M. Wazeer ◽  
M. Sakhawat Hussain ◽  
Joseph H. Reibenspies ◽  
Herman P. Perzanowski ◽  
...  
Keyword(s):  
Inversion Process ◽  
X Ray ◽  
Nitrogen Inversion
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