Question

Why percent yield of acylation of ferrocene to produce acetylferrocene so low?

Answer 1

The percent yield of acylation of ferrocene to produce acetylferrocene is low.

Explanation:

Ferrocene exhibits aromatic character, hence it is stable up to > 500 ^oC. It does not react readily with acids or bases; however, it is sensitive toward oxidizing agents. So, ferrocene has to be activated with powerful Lewis acid catalysts like AlCl₃. After the activation of ferrocene, acetylation occurs readily using a mild Brønstead-Lowry acid catalyst like H₃PO₄. In fact, ferrocene is so reactive to acetylation that a diacetyl derivative normally forms as a minor product.

As a result of the above observation, the yield of acetylferrocene is low.