Electroreductive defluorination of trifluoromethyl ketones and trifluoroacetic acid derivatives

Difluoroenol silyl ethers 5 and 6, difluoroketene silyl (O,O-, O,S-, and O, N-) acetals 9 and 21, and 2,2-difluoro-2-trimethylsilylacetates 10 were pre pared by electroreductive defluorination of trifluoromethyl ketones and tri fluoroacetic acid derivatives in an MeCN-TBAB-chlorotrialkylsilane system u sing a carbon rod as an anode and a lead plate as a cathode. TBAF- or KF-Cu I-promoted alpha-alkylation of 10 with electrophiles such as aldehydes, ket ones, imine, acylhalides, and alkylhalides provided alpha-alkylated-alpha,a lpha-difluoroacetates in good to excellent yields.