Efficient and Direct Nucleophilic Difluoromethylation of Carbonyl Compounds and Imines with Me3SiCF2H at Ambient or Low Temperature

Since 1995, Me3SiCF2H has been widely believed to be an inefficient difluoromethylating agent, which requires harsh reaction conditions to cleave its rather inert Si-CF2H bond. However, it has now been found that, by using a proper Lewis base activator, Me3SiCF2H can efficiently difluoromethylate various aldehydes, ketones, and imines to give the corresponding products in good to excellent yields at room temperature or even at -78 degrees C.