What are the limitations of the Foucault acylation reaction?

Although some limitations of related alkylation reactions (such as carbocation rearrangement and polyalkylation) have been overcome, there are some drawbacks to the Fourier acylation reaction.

① The acylation reaction produces only ketones. This is because formyl chloride decomposes into CO and HCl when exposed to these conditions.

② If the reactivity of aromatic compounds is lower than that of monohalobenzenes, they cannot participate in the reaction.

③ Aromatic amines cannot be used in this reaction because they form highly reactive complexes with Lewis acid catalysts.