Cleavage of Aromatic Carbon-Carbon Bonds

摘要

The search for a model substrate to use in evaluating relative reactivity of H-donors, under coal liquefaction conditions has led to this study of o-terphenyl. Results of cleavage reaction studies with o-terphenyl show that o-terphenyl couples in the presence of model H-donors and many coal derived solvents to form triphenylene, and forms biphenyl by cleavage. The latter reaction is of more interest as the yields are substantial, and the yields have application to the study of properties of solvents. Attempts to elucidate the mechanism involved kinetic studies, and reaction with a deuterated H-donor. The best mechanism appears to be that in which the low steady-state concentration of reactive H-donor attacks either ipso position in o-terphenyl followed by cleavage. This mechanism is known to occur at high temperatures. 7 references, 3 tables. (ERA citation 09:032450)