@article{76281d409b7c4af3b5368dbbd65c2a83,
title = "Arene 1,4-diradical formation from o-dialkynylarenes",
abstract = "A series of five arene and quinone derivatives with dialkynyl substituents in the ortho positions and fixed in a 10-membered ring were prepared and tested with respect to thermal rearrangement to the corresponding arene 1,4 diradicals.",
keywords = "4-diyls, Bergman rearrangment, arene-1, diyne-enes, o-dalkynylarenes",
author = "Semmelhack, {M. F.} and Thomas Neu and Francisco Foubelo",
note = "Funding Information: 4. (a) J. P. Snyder, J. Am. Chem. Sot., 1990, 112, 5367. (b) J. P. Snyder, J. Am. Chem. Sot., 1989, Ill, 7630. 5. The parent compound in this series is 6, which was observed as a reaction product6 but has not been directly synthesized nor observed in the Bergman rearrangement. More unsaturated analogs rearrange to potycyclic aromatics, presumably via the appropriate diyl. 637 The oxa analog. 5, has been prepared and rearranges with a half life of 52 hr at 37%. 8 The arene analog, 4, is suggested to rearrange rapidly under the conditions of its formation (25oC). Nicolaou has recently attached the arene-o-diyne to a model for dynemicin and observed Bergmann cyclization.9 6. N. Darby, C. U. Kim, J. A. Salaun, K. W. Shelton, S. Takada, S. Masamune, Chem. Comm., 1971, 1516. 7. H. N. C. Wong and F. Sondheimer, Tetrahedron Letf., 1980, 217. 8. R. Singh and G. Just, Tetrahedron Left., 1990, 185. 9. K. C. Nicolaou, Y-P. Hong, Y. Torisawa, S-C. Tsay, and W.-M. Dai, J. Am. Chem. Sue., 1991, 7 13, 9879. 10. For a related example, see: G. Just and Ft. Singh, Tetrahedron Lett., 1987, 5981. 11. T. Zincke and M. Schmidt; Chemische Berichte, 1894, 27, 2753.. 12. Characterization data for 16: m.p. >300°C (darkens above 100%). IR (KBr) 2942, 2932, 2190, 1666, 1595, 1369. 1323, 1301, 1204, 1006, 712 cm{\textquoteleft} {\textquoteleft}. {\textquoteright} H NMR (270 MHz, CDCl3): d 8.07 (2 H, dd, J=5.6, 3.3 Hz), 7.71 (2 H, dd, J&6, 3.3 Hz), 2.54-2.58 (4 H, m. 2 CH2), 1.94-1.98 (4 H, m. 2 CH2) ppm. 13C NMR (68 MHz, CDC13): d 180.61 (2 C=O), 139.51 (2 G), 133.99 (2 CH), 131.59 (2 C), 126.89 (2 CH), 116.26 (2 C=Q, 80.13 (2 C-Q, 28.19 (4 CH2), 22.53 (2 CH2) ppm. MS m/z 262 (M+, 2.93). 260 (M+. IOO), 247 (48), 231 (33), 203 (39), 202 (70), 176 (22), 170 (40). 13. Characterization data for 17 m.p.>SOO”C (darkens above lOO*C). IR (KBr) 3252, 2941, 2927, 2208, 1673, 1586, 1336, 1307, 1247, 938. 713 cm-{\textquoteleft}. {\textquoteright} H NMR (270 MHz, CDC13): d 8.28 (2 H, dd, J=6.0, 3.3 Hz), 8.17 (s, 2 H), 7.77 (2 H, dd, J=6.0, 3.3 Hz), 2.49-2.51 (4 H, m, 2 CH2), 1.95-1.99 (4 H, m, 2 CH2) ppm. 13C NMR (68 MHz, CDC13): d 182.19 (2 LO), 135.18 (2 C), 134.08 (2 CH), 133.48 (2 C), 131.81 (2 C), 127.20 (2 CH), 126.40 (2 CH), 105.25 (2 Q=C), 81.75 (2 C-Q;), 28.25 (2 CH2), 21.68 (2 CH2) ppm. Mass spectrum, m/z 310 (M+, IOO), 312 (M+, 2.31), 281 (27), 252 (50), 239 (26), 149 (36), 141 (36). MS talc.: 310.0994; found: 310.0981. 14. Characterization data for tetracenequinone 21 m.p. 209-211% (hexane/chloro-form). IR (KBr) 2932, 2861, 1677, 1590, 1333, 1290, 960, 715 cm-l. 1 H NMR (270 MHz, CDC13): d 8.27 (2 H, dd. J=5.6. 3.3 Hz), 7.96 (2 H, s, CH), 7.75 (2 H, dd, J&6, 3.3 Hz), 2.89-2.93 (4 H. m, 2 CH2), 1.82-1.87 (4 H, m, 2 CH2) ppm. l3C NMR (68 MHz, CDC13): d 183.33 (2 LO), 144.64 (2 C), 133.83 (2 CH), 133.77 (2 C), 131.02 (2 C), 131.02 (2 C), 127.93 (2 C), 127.08 (2 C), 29.83 (2 CH2), 22.56 (2 CH2) ppm. MaSS spectrum, m/z 262 (M+, loo), 247 (45), 170 (54), 141 (58), 77 (62). MS talc.: 262.09944; found; 262.0994. 15. Characterization data for pentacenequinone 20: m.p. 257-259°C (hexane/chloro-form). IR (KBr) 2931, 2919, 2862, 1672, 1585, 1454, 1407, 1321, 1284, 1234, 967, 716 cm-t. tH NMR (270 MHz, CDCl3): d 8.70 (2 H, s, ArH), 8.36 (2 H, dd, J=5.6, 3.3 Hz), 7.79 (2 H, dd, J&6, 3.3 Hz), 7.76 (2 H, s, Art-f), 2.98-3.01 (4 H, m, 2 CH2), 1.85-1.90 (4 H, m, 2 CH2) ppm. l3C NMR (67.9 MHz, CDC13): d 183.16 (2 C=O), 140.94 (2 C), 134.66 (2 C), 133.96 (2 CH), 133.70 (2 CH), 129.09 (2 CH), 128.88 (2C, 2CH), 127.41 (2 CH), 29.85 (2 CH2), 22.88 (2 CH2) ppm. MS m/z 312 (M+, 17.6), 297 (4.8), 170 (5.5), 85 (14). 83 (21). 16. The dimerization is postulated at the 9,lO position of the anthracene to give a symmetrical dimer. Exposure to air at 25O leads to an adduct which decomposes to 17 in moderate overall yield. Details of this process will be reported in the article describing this work. 17. We are pleased to acknowledge support in the form of research grants (American Cyanamid and the National Institutes of Health), a Fullbright postdoctoral fellowship to FF, and a DAAD Fellowship to TN.",
year = "1992",
month = jun,
day = "2",
doi = "10.1016/S0040-4039(00)92066-5",
language = "English (US)",
volume = "33",
pages = "3277--3280",
journal = "Tetrahedron Letters",
issn = "0040-4039",
publisher = "Elsevier Ltd",
number = "23",
}