1355176-96-3Relevant academic research and scientific papers
Hyperconjugative Antiaromaticity Activates 4 H-Pyrazoles as Inverse-Electron-Demand Diels-Alder Dienes
Levandowski, Brian J.,Abularrage, Nile S.,Houk,Raines, Ronald T.
, p. 8492 - 8495 (2019)
The Diels-Alder reactivity of 4,4-difluoro-3,5-diphenyl-4H-pyrazole was investigated experimentally and computationally with endo-bicyclo[6.1.0]non-4-yne. The computationally predicted rate enhancement from hyperconjugative antiaromaticity induced by fluo
Synthesis, characterization, and cycloaddition reactivity of a monocyclic aromatic 1,2,3,5-tetrazine
Wu, Zhi-Chen,Boger, Dale L.
supporting information, p. 16388 - 16397 (2019/10/16)
Herein we disclose the synthesis and full characterization of the first monocyclic aromatic 1,2,3,5-tetrazine, 4,6-diphenyl-1,2,3,5-tetrazine. Initial studies of its cycloaddition reactivity, mode, regioselectivity, and scope illustrate that it participates as the 4π-component of well-behaved inverse electron demand Diels-Alder reactions where it preferentially reacts with electron-rich or strained dienophiles. It was found to exhibit an intrinsic reactivity comparable to that of the isomeric 3,6-diphenyl-1,2,4,5-tetrazine, display a single mode of cycloaddition with reaction only across C4/N1 (no N2/N5 cycloaddition observed), proceed with a predictable regioselectivity (dienophile most electron-rich atom attaches to C4), and manifest additional reactivity complementary to the isomeric 1,2,4,5-tetrazines. It not only exhibits a remarkable cycloaddition reactivity, surprisingly good stability (e.g., stable to chromatography, long-term storage, presence of H2O even as reaction co-solvent), and broad cycloaddition scope, but it also displays powerful orthogonal reactivity with the 1,2,4,5-tetrazines. Whereas the latter reacts at extraordinary cycloaddition rates with strained dienophiles (tetrazine ligation), the new and isomeric 1,2,3,5-tetrazine displays similarly remarkable cycloaddition rates and efficiencies with amidines (1,2,3,5-tetrazine/amidine ligation). The crossover reactivities (1,2,4,5-tetrazines with amidines and 1,2,3,5-tetrazines with strained dienophiles) are sufficiently low to indicate they may be capable of use concurrently without competitive reactions.
3,6-Substituted-1,2,4,5-tetrazines: Tuning reaction rates for staged labeling applications
Wang, Danzhu,Chen, Weixuan,Zheng, Yueqin,Dai, Chaofeng,Wang, Ke,Ke, Bowen,Wang, Binghe
, p. 3950 - 3955 (2014/06/09)
Cycloaddition reactions involving tetrazines have proven to be powerful bioorthogonal tools for various applications. Conceivably, sequential and selective labeling using tetrazine-based reactions can be achieved by tuning the reaction rate. By varying th
Clicking 1,2,4,5-tetrazine and cyclooctynes with tunable reaction rates
Chen, Weixuan,Wang, Danzhu,Dai, Chaofeng,Hamelberg, Donald,Wang, Binghe
, p. 1736 - 1738 (2012/03/09)
Substituted tetrazines have been found to undergo facile inverse electron demand Diels-Alder reactions with "tunable" reaction rates.
