Difluoromethyl trifluoromethyl ether

Difluoromethyl trifluoromethyl ether CHF2OCF3 106 + 1 443.5+4.2 Kinetics 1995HSU/DEM... 

Substitution of hydrogen by fluorine also occurs, albeit with difficulty, in the formyl group of formates ethyl formate reacts with sulfur tetrafluoride in the presence of potassium fluoride to give a mixture of difluoromethyl ethyl ether (14) and ethyl trifluoromethyl ether (15).175... 

Difluoromethyl methyl ether (CH3OCHF2) 3) Methyl trifluoromethyl ether (CF3OCH3,... 

Silyl enol ethers have also been used as a trap for electrophilic radicals derived from a-haloesters [36] or perfluoroalkyl iodides [32]. They afford the a-alkylated ketones after acidic treatment of the intermediate silyl enol ethers (Scheme 19, Eq. 19a). Similarly, silyl ketene acetals are converted into o -pcriluoroalkyl esters upon treatment with per fluoro alkyl iodides [32, 47]. The Et3B/02-mediated diastereoselective trifluoromethylation [48,49] (Eq. 19b) and (ethoxycarbonyl)difluoromethylation [50,51] of lithium eno-lates derived from N-acyloxazolidinones have also been achieved. More recently, Mikami [52] succeeded in the trifluoromethylation of ketone enolates... 

Fluoride ion-catalysed addition of trifluoromethyltrimethylsilane to acyl silanes occurs to give l,l-difluoro-2-trimethylsilyloxyalkenes (silyl enol ethers of difluoromethyl ketones), through nucleophilic addition of trifluoromethyl anion, Brook rearrangement and loss of fluoride. These compounds could be isolated when tetrabutylammonium difluorotriphenylstannate was used as a catalyst use of tetrabutylammonium fluoride gave the product corresponding to subsequent aldol reaction with the difluoromethyl ketone (Scheme 78)m. 

Also difluoromethyl ketones can be reduced by magnesium to the corresponding fluorenol ethers [32]. Thus, by application of one or two sequential reduction-desi-lylation steps, trifluoromethyl ketones can be converted into difluoromethyl and fluoromethyl ketones (Scheme 2.198). Deuterodesilylation instead ofthe usual pro-todesilylation enables convenient access to deuterated analogs of these compounds. 

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