Electrophilic Aromatic Formylation with Difluoro(phenylsulfanyl) methane

Difluoro(phenylsulfanyl)methane (PhSCF 2 H) was found to undergo a reaction with aromatic compounds mediated by SnCl 4 , through a thionium intermediate characterized by NMR and TD-DFT analyses, leading to the formation of a mixture of S , S ′-diphenyl dithioacetal and aromatic aldehyde which, after oxidative hydrolysis, provides the aromatic aldehyde in good to excellent yields. The salient feature of the present work is the reaction of activated aromatic compounds containing a deactivating ester functional group, leading to the formylated products in good yields.