The carbocation salt [PhC][BArF] has been identified as a viable Lewis acid catalyst for the Diels-Alder reactions between anthracene derivatives and unsaturated carbonyl compounds with good selectivity and high efficiency.

The combination of the trityl cation and a chiral weakly coordinating Fe(III)-based bisphosphate anion was used to develop a new type of a highly active carbocation Lewis acid catalyst. The stereocontrol potential of the chiral tritylium ion pair was demonstrated by its application in an enantioselective Diels–Alder reaction of anthracene.

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