Tetrazolo[1,5-a]pyridines and furazano[4,5-b]pyridine 1-oxides

Lowe-Ma, Charlotte K.; Nissan, Robin A.; Wilson, William S.

doi:10.1021/jo00299a014

Cited by 104 publications

(61 citation statements)

References 5 publications

(23 reference statements)

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“…The very high reactivity and the application of organoazides in synthetic chemistry and many important industries [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] has drawn the attention to investigate the structure and conformational behavior of vinyl azide, CH2=CH-NNN [37] and formyl azide, CHO-NNN [38], by DFT and ab initio MP2 calculations. Both molecules were predicted to have a cis/trans conformational equilibrium with the gauche form being the transition state.…”

Section: Introductionmentioning

confidence: 99%

Structural Stability and Vibrational Analyses of Haloselenonyl Azides, XSeO2-NNN, where X is F, Cl, Br

Förner

Badawi

Seddigi

2005

IJMS

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Abstract:The structural stability of haloselenonyl azides was investigated by quantum mechanical Møller-Plesset perturbation theory of second order and density functional theory calculations. The 6-311+G** basis set was used to include polarization and diffuse functions in the calculations at the DFT-B3LYP level. The potential scans for the rotation of the -NNN rotor were calculated and found to be consistent with a single minimum that corresponds to a gauche conformation (-NNN moiety nearly eclipses one of the two selenonyl Se=O bonds) for the three halogens at ambient temperature. The structural parameters for the minima calculated by MP2 and DFT turned out to be very similar. The vibrational modes, infrared and Raman intensities as well as depolarization ratios were calculated at DFT-B3LYP/6-311+G** level for the three molecules in their gauche conformations. The potential energy distributions among symmetry coordinates of the normal modes of the molecules in their gauche conformation were then computed from normal coordinate analyses.

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Section: Introductionmentioning

confidence: 99%

Structural Stability and Vibrational Analyses of Haloselenonyl Azides, XSeO2-NNN, where X is F, Cl, Br

Förner

Badawi

Seddigi

2005

IJMS

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“…[60] In contrast to tetrazolo[1,5-a]pyridine 50 (Scheme 8), 6-nitrotetrazolo[1,5-a]pyridine 58T exists in equilibrium with a small amount of the azide valence isomer 58A at room temperature. [61] Chollet observed that the FVT of this material at 4008C/10 À3 hPa afforded a 15-20 % yield of 2-cyanopyrrole 31 as well as NO 2 as the only low molecular weight products (Scheme 10). [62] NO 2 was identified by its IR spectrum [63] in the gas-phase.…”

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confidence: 99%

Chemical Activation in Azide and Nitrene Chemistry: Methyl Azide, Phenyl Azide, Naphthyl Azides, Pyridyl Azides, Benzotriazoles, and Triazolopyridines

Wentrup¹

2013

Aust. J. Chem.

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Chemical activation (the formation of 'hot' molecules due to chemical reactions) is ubiquitous in flash vacuum thermolysis (FVT) reactions, and awareness of this phenomenon is indispensable when designing synthetically useful gas-phase reactions. Chemical activation is particularly prevalent in azide chemistry because the interesting singlet nitrenes are high-energy intermediates, and their reactions are highly exothermic. Consequently, chemical activation is observed in the isomerization of methylnitrene CH 3 N to methylenimine (methanimine) CH 2 ¼NH, facilitating the elimination of hydrogen to form HCN or HNC. Rearrangements of phenylnitrene, 1-and 2-naphthylnitrenes, and 2-, 3-and 4-pyridylnitrenes afford cyanocyclopentadiene, 3-and 2-cyanoindenes, and 2-and 3-cyanopyrroles, all showing the effects of chemical activation by undergoing facile interconversion of isomers. Chemical activation can often be reduced or removed entirely by increasing the pressure, thereby promoting collisional deactivation. Larger molecules having more degrees of freedom are better able to dissipate excess energy; therefore the effects of chemical activation are less pronounced or completely absent in the formation of 3-cyanoindole and 1-cyanobenzimidazoles from 3-and 4-quinolylnitrenes and 4-quinazolinylnitrenes, respectively. In compounds possessing nitro groups, chemical activation can cause the loss of the nitro group at nominal temperatures far below those normally needed to cleave the C-NO 2 bond.

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“…[8]: P(1)ÀC(1): 1.717(6), P(1)ÀN(1): 1.696(4), C(1)ÀN(3): 1.370 (8), N(3)ÀN(2): 1.320 (7), N(2)ÀN(1): 1.358 (6), N(1)ÀC(2): 1.444(7), C(2)ÀC(3): 1.376(8), C(2)À C(6): 1.388 (7), N(4)ÀC(6): 1.341(8),C(1)ÀC (7) double bond ((diphenylmethylene)(mesityl)phosphine;M esP= CPh 2 :1 .692 ) and aP ÀCs ingle bond (PPh 3 :1 .83 ). [16] The N-P-C angle is, at 85.77(8)8,a lmost 908 and differs significantly from the C-P-C angle in the aromatic six-membered phosphorus heterocycles ( % 1008).…”

Section: Synthesis and Characterisationmentioning

confidence: 99%

“…Crystallographic data: C 13 H 13 BrN 4 O 3 PRe·CH 2 Cl 2 ; M r = 655.28;0 .34 0.09 0.08 mm 3 ;y ellow needles, triclinic; P1 ; a = 13.4120(11), b = 18.0785(18), c = 8.6707(8) ; a = 89.999 (8), b = 91.816(7), g = 89.998(7)8; V = 570.0(2) 3 ; Z = 4; D x = 2.071 gcm À3 ; m = 8.0355 mm À1 ;2 2878 reflections were measured by using aS toe IPDS 2T diffractometer with ar otating anode (Mo Ka radiation; l = 0.71073 ) up to ar esolution of sin q/l) max = 0.69 À1 at at emperature of 200 K. The reflections were corrected for absorption and scaled on the basis of multiple measured reflections by using the X-Red program (0.73-0.91 correction range). [30] 11 254 reflections were unique (R int = 0.222).…”

Section: X-ray Crystal-structure Determinationo F7amentioning

confidence: 99%

“…Indeed, it has been shown that pyridotetrazole F is inert towards click reactions under standard conditions because the equilibrium for this particular compound is shifted far to the left (Figure 2). [8] However,f ew examples have been reportedi nt he literature on successful click reactions of alkynes with pyridotetrazoles at T = 120 8C, and the coordination chemistry of such inverse 2-pyridyl-triazolesh as been investigatedt os ome extent. [9] This inherent drawback seems to be particularly problematic for the synthesis of pyridyl-functionalised triazaphospholes because one has to startf rom pyridotetrazole as an azide surrogate, since pyridine-derived phosphaalkynes are not available.…”

Section: Introductionmentioning

confidence: 99%

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Pyridyl‐Functionalised 3H‐1,2,3,4‐Triazaphospholes: Synthesis, Coordination Chemistry and Photophysical Properties of Low‐Coordinate Phosphorus Compounds

Sklorz

Hoof

Rades

et al. 2015

Chemistry A European J

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Novel conjugated, pyridyl-functionalised triazaphospholes with either tBu or SiMe3 substituents at the 5-position of the N3 PC heterocycle have been prepared by a [3+2] cycloaddition reaction and compared with structurally related, triazole-based systems. Photoexcitation of the 2-pyridyl-substituted triazaphosphole gives rise to a significant fluorescence emission with a quantum yield of up to 12 %. In contrast, the all-nitrogen triazole analogue shows no emission at all. DFT calculations indicate that the 2-pyridyl substituted systems have a more rigid and planar structure than their 3- and 4-pyridyl isomers. Time-dependent (TD) DFT calculations show that only the 2-pyridyl-substituted triazaphosphole exhibits similar planar geometry, with matching conformational arrangements in the lowest energy excited state and the ground state; this helps to explain the enhanced emission intensity. The chelating P,N-hybrid ligand forms a Re(I) complex of the type [(N^N)Re(CO)3 Br] through the coordination of nitrogen atom N(2) to the metal centre rather than through the phosphorus donor. Both structural and spectroscopic data indicate substantial π-accepting character of the triazaphosphole, which is again in contrast to that of the all-nitrogen-containing triazoles. The synthesis and photophysical properties of a new class of phosphorus-containing extended π systems are described.

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Tetrazolo[1,5-a]pyridines and furazano[4,5-b]pyridine 1-oxides

Cited by 104 publications

References 5 publications

Structural Stability and Vibrational Analyses of Haloselenonyl Azides, XSeO2-NNN, where X is F, Cl, Br

Structural Stability and Vibrational Analyses of Haloselenonyl Azides, XSeO2-NNN, where X is F, Cl, Br

Chemical Activation in Azide and Nitrene Chemistry: Methyl Azide, Phenyl Azide, Naphthyl Azides, Pyridyl Azides, Benzotriazoles, and Triazolopyridines

Pyridyl‐Functionalised 3H‐1,2,3,4‐Triazaphospholes: Synthesis, Coordination Chemistry and Photophysical Properties of Low‐Coordinate Phosphorus Compounds

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