133744-89-5Relevant academic research and scientific papers
gem-Difluorocyclopropanes: An improved method for their preparation
Bessard, Yves,Mueller, Ulrich,Schlosser, Manfred
, p. 5213 - 5221 (1990)
By treatment with dibromodifluoromethane and triphenylphosphine, four unfunctionalized olefins, four enethers and one bis-enether were converted to the gem-difluorocyclopropanes 1-9. The yields were considerably increased and isomerizations at the double bonds were avoided if the reactions were carried out in the presence of a macrocyclic polyether such as "18-crown-6" and if, in addition, the reagents were employed in moderate excess.
Trimethylsilyl fluorosulfonyldifluoroacetate (TFDA): A new, highly efficient difluorocarbene reagent
Dolbier Jr., William R.,Tian, Feng,Duan, Jian-Xin,Li, An-Rong,Ait-Mohand, Samia,Bautista, Olivia,Buathong, Saiwan,Baker, J. Marshall,Crawford, Jen,Anselme, Pauline,Cai, Xiao Hong,Modzelewska, Aneta,Koroniak, Henryk,Battiste, Merle A.,Chen, Qing-Yun
, p. 459 - 469 (2007/10/03)
TFDA is readily prepared from the reaction of fluorosulfonyldifluoroacetic acid with trimethylsilyl chloride, and it is a very effective and efficient source of difluorocarbene for use in addition reactions to alkenes of a broad scope of reactivities. Acid-sensitive substrates may require an additional purification step involving treatment of the distilled TFDA with sufficient Et3N to remove the acid impurity. Other trialkylsilyl fluorosulfonyldifluoroacetates can also be prepared, and they have been found to have reactivities similar to TFDA. The triethyl derivative, TEFDA is more convenient to prepare in a pure state and has similar reactivity to TFDA. Thus, it may prove to be a superior reagent.
