1274916-49-2Relevant academic research and scientific papers
Interaction of 1,3,2,4-benzodithiadiazines and their 1-Se congeners with Ph3P and some properties of the iminophosphorane products
Makarov, Alexander Yu.,Zhivonitko, Vladimir V.,Makarov, Arkady G.,Zikirin, Samat B.,Bagryanskaya, Irina Yu.,Bagryansky, Victor A.,Gatilov, Yuri V.,Irtegova, Irina G.,Shakirov, Makhmut M.,Zibarev, Andrey V.
, p. 3017 - 3027 (2011)
Interaction between Ph3P and 1,3,2,4-benzodithiadiazine (1); its 6,7-difluoro (2), 5,6,8-trifluoro (3) and 5,6,7,8-tetrafluoro (4) derivatives; and 5,6,8-trifluoro-3,1,2,4-benzothiaselenadiazine (5) proceeded via a 1:1 condensation to give Ph3P=N-R iminophosphoranes (1a-5a, R = corresponding 1,2,3-benzodichalcogenazol-2-yls), which are inaccessible by general approaches based on the Staudinger and Kirsanov reactions. In contrast, neither Ph3As nor Ph3Sb reacted with 1 and 4. Molecular structures of 1a-5a and 5 were confirmed by X-ray diffraction (XRD). The crystals formed by chiral molecules of 2a-5a were racemic, whereas the crystal of 1a was formed by a single enantiomer. In all of the Ph3P=N-R derivatives, one of the Ph rings is oriented face-to-face to the hetero ring, R. Upon heating to ～120 °C in squalane (1a, 3a, 4a) or dissolving in chloroform at ambient temperatures (1a, 2a, 4a), the Ph3P=N-R derivatives generated the 1,2,3-benzodithiazolyls (1b-4b, respectively) whose identity was confirmed by electron paramagnetic resonance (EPR). 2,1,3-Benzothiaselenazolyls 5b and 6b were detected by EPR as the main paramagnetic products of solution thermolysis of 5 and its 5,6,7,8-tetrafluoro congener (6), respectively. Passing a chloroform solution of 4a through silica column unexpectedly gave 5-6-6-6 tetracyclic (9) and 6-10-6 tricyclic (10) sulfur-nitrogen compounds, which were characterized by XRD.
