A m-benzyne to o-benzyne conversion through a 1,2-shift of a phenyl group.
Pyrolysis of two differently labeled versions of 3-phenylphthalic anhydride shows that a m-benzyne can form the related o-benzyne through shift of a phenyl group. The highest energy point in the process is the transition structure for a reverse carbon-hydrogen insertion in an intermediate benzopentalene. With the minor addition of an intermediate alkyne formed through a Roger Brown rearrangement, the original mechanism for formation of acenaphthalene accommodates the labeling results.
Blake
Michael E
ME
Contribution from the Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA.
Bartlett
Kevin L
KL
Jones
Maitland
M