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An efficient organocatalytic method for the synthesis of new substituted 9-arylxanthenes (2a–2u) starting from diarylcarbinol compounds with an arenoxy group (1a–1u) has been developed using the intramolecular Friedel–Crafts reaction. The substrates were prepared in two steps by Ullmann-type coupling and then Grignard reaction. Some organic Brønsted acids were studied as catalysts (3a–3g) in the intramolecular Friedel–Crafts alkylation reaction for the first time. N-triflylphosphoramide (3g) provided the synthesis of some novel substituted 9-arylxanthenes with excellent yields at room temperature within 15 minutes.