Abstract We have investigated the different chlorodifluoromethyl aryl ketones 1a–1g and sulfones 2a–2h as difluorocarbene reagents for O-and N-difluoromethylations. It was found that the sulfone reagents 2 were generally more efficient in difluoromethylation than the ketone reagents 1. Furthermore, while the different substituents on ketone reagents 1 did not show a remarkable impact on the difluoromethylation reaction, the substituent effect on the ...