10.1021/jo0526744.s001
Pawel Rempala
Pawel
Rempala
Jiří Kroulík
Jiří
Kroulík
Benjamin T. King
Benjamin T.
King
Investigation of the Mechanism of the Intramolecular Scholl
Reaction of Contiguous Phenylbenzenes
American Chemical Society
2006
Scholl reaction
mass balance experiments
Intramolecular Scholl Reaction
bond
generation
Contiguous PhenylbenzenesTwo mechanisms
arenium cation
MoCl 5
formation
FeCl 3
Reaction optimization studies
Kinetic simulations
dehydrogenation
activation energies
arenium cation mechanism
B 3LYP level
2006-07-07 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Investigation_of_the_Mechanism_of_the_Intramolecular_Scholl_Reaction_of_Contiguous_Phenylbenzenes/3071875
Two mechanisms of the Scholl reaction were investigated in the series 1, 2, ..., <i>n</i>-oligophenylbenzenes
(<i>n</i> = 2, 3, 4, 6) at the B3LYP/6-31G(d) level of theory. A mechanism involving generation of a radical
cation followed by C−C bond formation and dehydrogenation is unlikely on the basis of unfavorable
energies of activation. A mechanism involving generation of an arenium cation followed by C−C bond
formation and dehydrogenation is energetically feasible. An explanation for the facile polycondensation
of hexaphenylbenzene to hexa-<i>peri</i>-hexabenzocoronene, where six new aryl−aryl bonds are formed, is
provided. Kinetic simulations based on the calculated activation energies of the arenium cation mechanism
predict that intermediates will not accumulate; this is supported by mass balance experiments. Reaction
optimization studies suggest that PhI(O<sub>2</sub>CCF<sub>3</sub>)<sub>2</sub>/BF<sub>3</sub>·OEt<sub>2</sub> or MoCl<sub>5</sub> are superior to FeCl<sub>3</sub> or AlCl<sub>3</sub>/CuCl<sub>2</sub>.
This is a full account of our work reported partially as a communication previously (Rempala, P.; Kroulík,
J.; King, B. T. <i>J. Am. </i><i>Chem. Soc.</i> <b>2004</b>, <i>126</i>, 15002−15003).