This paper describes the synthesis of unprecedentedfused nitroazaheterocyclic ring systems. Nitro tricycles with a central 1,2,3-triazole ring were obtained via a nitrene-mediated reaction of azidonitrobis(hetaryl) derivatives under thermolysis. The cyclization proceeded with complete chemoselectivity for the desired N-N bond formation. The key azidonitro bicycles were synthesized through an aromatic
本文描述了前所未有的稠合硝基氮杂杂环系统的合成。具有中心 1,2,3-三唑环的硝基三环是通过氮烯介导的叠氮硝基双(杂芳基)衍生物在热解下的反应获得的。环化以完全化学选择性进行,以形成所需的 NN 键。关键的叠氮硝基双环是通过硝基唑和 3-叠氮基-2-氯吡嗪的芳香亲核取代合成的。
Nitrile Ylides: Allenic and Propargylic Structures from Pyrazinylnitrenes. Experimental and Theoretical Characterization
Matrix photolysis of 2-pyrazinyl azides/tetrazolo[1,5-a]pyrazines generates nitrile ylides 15 via pyrazinylnitrenes 13 and triazacycloheptatetraenes 14. The nitrile ylides 15 are characterized by IR spectroscopy in conjunction with harmonic and anharmonic vibrational frequency calculations. The nitrile ylides exist in the matrices in the Z,Z-conformations in which they are born. Substitution on the nitrile carbon of nitrile ylides has a profound effect on their structure. Even different conformers of the same molecule can have differences up to 200 cm(-1) in the IR absorptions of the ylide moieties. Nitrite ylides 15a and 15b (R = H or Cl, R' = H) have allenic structures (15 Allenic). Nitrile ylide 15c (R = R' = CH3) has a distinctly propargylic structure (15 Propargylic) in the experimentally observed Z,Z-conformation.