Formylation of Aromatic Compounds with CO in HSO3F-SbF5 under Atmospheric Pressure

Article abstract of DOI:10.1021/jo00035a024

The formylation of aromatic compounds such as benzene, toluene, xylenes, mesitylene, indan, tetralin, fluorobenzene, chlorobenzene, and bromobenzene was carried out in HSO3F-SbF5 under atmospheric CO pressure at 0 deg C.In HSO3F-SbF5, both formylation and sulfonation took place to give formyl and sulfonyl compounds.In the case of alkylbenzenes, including toluene, xylenes, mesitylene, and tetralin, formylalkylbenzenesulfonyl fluorides, new compounds, were obtained by a one-pot reaction as well as alkylbenzaldehydes, alkylbenzenesulfonyl fluorides, and bis(alkylphenyl) sulfones.The direct introduction of a formyl and sulfonyl group was achieved in alkylbenzenes.The reaction path of the new compounds is a two-step reaction comprised of formylation as the first step and sulfonation as the second step.The product composition was strongly dependent on the acid strength of the HSO3F-SbF5 systems.The formyl compounds became predominant with increasing acidity of the HSO3F-SbF5 system.On the other hand, only sulfonyl compounds were produced when the acidity of the HSO3F-SbF5 system was low.