Synthesis of 9-cyanophenanthrene–furan and –benzene cyclodimers and their reversion

[2+2] Heterodimers of methyl phenanthrene-9-carboxylate and benzene

“…The activation parameters, obtained from transition state theory, 20 are summarized in Table 1, and compared with those for the anti-[2+2] heterodimer ( 10) of 9-cyanophenanthrene and benzene. 5 High activation enthalpies and little or no activation entropies for 1 and 2, as usually found in a highly exoergic process, 1 indicate that they undergo the thermoreversion in a stepwise mechanism. As expected, 1 and 2 were found to be more stable than 10.…”

“…Most studies were carried out with the units of benzene, 1 furan, 9,10 naphthalene 2,4 and anthracene. 3,4 We recently extended the unit components by synthesizing the anti-[2+2] heterodimers of 9-cyanophenanthrene and small arenes (benzene and furan) 5 and the [2+2] heterodimers of acenaphthylenes and benzene. 6 To the best of our knowledge, only two studies comparing the properties of syn-and anti-[2+2] dimers, dibenzenes 1 and acenaphthylenes-benzene heterodimers, 6 have been reported.…”