Dihydro‐ und Tetrahydroderivate des 3,6‐Dimethyl‐1,2,4,5‐tetrazins

Skorianetz, W.; Kováts, Ervin sz.

doi:10.1002/hlca.19720550506

Cited by 23 publications

(9 citation statements)

References 7 publications

(7 reference statements)

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“…Bei 1 betragt der Schnittwinkel der N(2), C(3), N(5), C(6)-und der C(3), N(4), N(5)-bzw. C (6), N(I), N(2)-Ebenen 32"; fur 9 und 13 a Abb. (9) 285 (7) 825 (4) 310 (2) 686 (13) 525 ( (1) 381 (5) 354 (5) 344 (6) 370 (5) 369 (5) 382 (6) 491 (I) 350 (6) 450 (7) 410 ( 6.3 (4) 508 11) 318 (5) 512 (6) 341 ( (6) 629 (7) 309 (5) 610 (I) 364 (5) 481 (8) 380 (6) 553 (8) 444 17) 502 (7) 3 W (5) 524 (8) #I (6) 122 (9) 536 (8) 193 ( Phosphorpentachlorid in 200 ml Tetrachlorkohlenstoff wurden 10 h unter RuckfluB erhitzt.…”

Section: Riintgenstrukturanalysen Von 1 9 13 Und 16*)unclassified

Über 1,4‐Dihydro‐1,2,4,5‐tetrazine

et al. 1983

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Die Stammverbindung 1 sowie die Derivate 9 und 13 liegen nach Rontgenstrukturanalysen in der 1,4-Dihydroform vor. Eingehende Untersuchungen der Elektronenspektren von 1 -16 zeigen, daR auch in Losung die 1,4-Dihydroform thermodynamisch bevorzugt ist . Eine Reihe neuer l,J-Dihydro-l,2,4,5-tetrazin-Radikalkationen wurde ESR-spektroskopisch untersucht.A Study of 1,4-Dihydro-1,2,4,5-tetrazines X-ray structure analysis of the primary compound 1 and the derivatives 9 and 13 yields a 1,4-dihydro structure. Detailed studies of the electronic spectra of 1 -16 show that also in solution the 1,4-dihydro form is thermodynamicly favoured. A series of new 1,4-dihydro-l,2,4,5-tetrazine radical cations was studied by e.s.r.

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Section: Riintgenstrukturanalysen Von 1 9 13 Und 16*)unclassified

Über 1,4‐Dihydro‐1,2,4,5‐tetrazine

et al. 1983

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“…In spite of lost aromaticity, the reaction is thermodynamically favorable; this is Equation (1) in Figure , where the 2 “H” reduce Me 2 Tz. It is established that 1,4‐dihydrotetrazine is more stable than 1,2‐dihydrotetrazine, but isomerization between them (proton transfer) is facile.…”

Section: Resultsmentioning

confidence: 99%

“…[27] Several aryldiazo compounds were reported as effective alternatives to DEAD, and produce readily separable arylhydrazine byproducts that can be regenerated by oxidation with iodosobenzenediacetate [26a,b] or even by oxygen, in the presence of porphyrin-based iron catalyst. [26d] Te trazines are potentially attractive for several reasons: they are easily synthesized in one step from inexpensive starting materials such as nitrilesa nd hydrazine, [28] both electronic and steric properties could be finely tuned by variation of ringcarbon substituents, and dihydrotetrazine side products could be easily reoxidized to tetrazines, sometimes with atmospheric oxygen [12] or with NaNO 2 and acid [28b, 29] with highyields.…”

Section: Tetrazines As Reagents For the Mitsunobu Reactionmentioning

confidence: 99%

Tetrazine Assists Reduction of Water by Phosphines: Application in the Mitsunobu Reaction

Polezhaev

Maciulis

Chen

et al. 2016

Chemistry A European J

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Reaction of 3,6-disubstituted-1,2,4,5-tetrazines with water and PEt forms the corresponding 1,4-dihydrotetrazine and OPEt . Thus PEt , as a stoichiometric reductant, reduces water, and the resulting two reducing equivalents serve to doubly hydrogenate the tetrazine. A variety of possible initial interactions between electron-deficient tetrazine and electron-rich PR , including a charge transfer complex, were evaluated by density functional calculations which revealed that the energy of all these make them spectroscopically undetectable at equilibrium, but one of these is nevertheless suggested as the intermediate in the observed redox reaction. The relationship of this to the Mitsunobu reaction, which absorbs the components of water evolved in the conversion of alcohol and carboxylic acid to ester, with desirable inversion at the alcohol carbon, is discussed. This enables a modified Mitsunobu reaction, with tetrazine replacing EtO CN=NCO Et (DEAD), which has the advantage that dihydrotetrazine can be recycled to tetrazine by oxidation with O , something impossible with the hydrogenated DEAD. For this tetrazine version, a betaine-like intermediate is undetectable, but its protonated form is characterized, including by X-ray structure and NMR spectroscopy.

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“…363-365 K, lit. 364-365 K (Skorianetz & Kovats, 1972); very volatile solid slowly crystallized from dried hexanes; irregularly shaped piece (0.30 × 0.30 × 0.64 mm) cut from larger crystal and mounted in capillary. Unit-cell parameters (least squares) from 20 reflections in 0 range 6-13°; Enraf-Nonius CAD-4 diffractometer (graphite monochromator); data corrected for Lorentz and polarization factors but not for absorption; min.…”

Section: Introductionmentioning

confidence: 99%