It must also be stated that removal of the aryl ring entirely resulted in a drastic increase in oxidation potential (5ao), presumably due to the inability of the corresponding radical cation to delocalise into the aromatic system. From the data obtained from these cyclic voltammetry studies, a redox window for reactivity was established allowing BCB compounds to first be analysed using this technique and then only be employed if their oxidation potential falls within this potential range. Using this guiding principle, a variety of aryl substitution patterns, different ester groups, amides and ketones were all shown to be suitable substrates in this transformation (5ap-ax).