Preparation of 1,1-difluoroalkanes from aldehydes via 1,1-bistriflates: Advantageous use of HF-Lewis base reagents

Alkane-1,1-bistriflates, prepared in excellent yields by reaction of aldehydes with triflic anhydride, are converted to their respective 1,1-difluoroalkanes in good to excellent yield through reaction with fluorinating agent, triethylaminetrishydrofluoride. Straight chain 1,1-bistriflates are more reactive than those substituted at the 2-position, but the latter are also converted successfully, without evidence of any rearrangement products. (C) 2014 Elsevier B.V. All rights reserved.