Iranian Journal of Catalysis (IJC) Study of an in situ carbocationic system formed from trityl chloride (Ph3CCl) as an efficient organocatalyst for the condensation of dimedone with arylaldehydes Volume 3 (2013) Issue 2, June 2013 2024 02 03 Study of an in situ carbocationic system formed from trityl chloride (Ph3CCl) as an efficient organocatalyst for the condensation of dimedone with arylaldehydes EN Abdolkarim Zare Department of Chemistry, Payame Noor University, PO Box 19395-3697, Tehran, Iran 0000-0002-8210-3155 Maria Merajoddin Department of Chemistry, Payame Noor University, Iran. Mohammad Ali Zolfigol Department of Organic Chemistry, Faculty of Chemistry, Bu-Ali Sina University, Hamedan 6517838683, Iran. Journal Article 2024 02 03 Organocatalyst trityl chloride (Ph3CCl), by in situ formation of trityl carbocation with inherent instability, efficiently catalyzes the condensation of dimedone (5,5-dimethyl-1,3-cyclohexanedione) (2 equiv.) with arylaldehydes (1 equiv.) under solvent-free conditions to afford 9-aryl-1,8-dioxo-octahydroxanthenes in high to excellent yields and in relatively short reaction times. Formation of the carbocationic system is confirmed by studying IR, 1H NMR and UV spectra according to the literature. Moreover, a plausible mechanism based on the literature and observations is proposed for the reaction.