Figure 2.
Earliest reports of cyclization of a triyne to a benzyne intermediate. (a)formattingasusedbyChemRev Ueda and coworkers (1997): trapping of the benzyne II with anthracene gives the triptycene 7. (b) Johnson and coworkers (1997): high temperature (short time) cycloisomerization of 8 to 10 via III and 9. (c) Sterenberg and Tsui (2009): intra-annular cyclization of dinuclear complex 11 in the presence of furan gives the adduct 12 via IV.