Can anyone explain why the acylation of ferrocene produces the following results:
Ferrocene + acetic anhydride + AlCl3 ==> mono-acylated ferrocene
Ferrocene + acetyl chloride + AlCl3 ==> di-acylated ferrocene (an acyl group on each ring).
I have seen various statements confirming this, but not a single explanation for it! My current thoughts are that it must be something to do with the carboxylic acid produced from the reaction with the anhydride somehow hydrogen bonding/blocking the second site, but not really sure how it would work.
Any explanations greatly appreciated!