A Novel Reaction of (2,4,7-Trinito-9H-fluoren-9-ylidene)-propanedinitrile with N-Arylisoindolines

Article abstract of DOI:10.1002/jhet.5570350123

N-Arylisoindolines 1a-c reacted with (2,4,7-trinitro-9H-fluoren-9-ylidene)propanedinitrile (A) in pyridine with admission of air via a net α-H-atom abstraction and formation of [3-(2-aryl-3-arylimino-2,3-dihydro- 1H-isoindol-1-ylidene)-2-aryl-2,3-dihydro-1H-isoindol-1-ylidene] propanedinitriles 2a-c, N-[2-aryl-3-(2-aryl-3-arylimino-2,3-dihydro-1H-isoindolyl-1-idene)-2,3-dihydro- 1H-isoindol-1-ylidene]arenamines 3a,b, N,N-[2-aryl-1H-isoindole-1,3(2H)-diylidene]bisarenamines 4a,b and N-arylphthalimides 5a-c in moderate yields. 2,4,7-Trinitro-9-fluorenone as well as one reduction product each of the latter and of A, namely compounds 6 and 7, respectively, are also found. The structure of 2b has been unambiguously confirmed by an X-ray crystal structure analysis. A rationale for the conversions observed is presented. These involve dehydrogenation and oxidative couplings of 1a-c as well as transfer of N-aryl fragment from 1a-c to intermediate products.