Sung Lan Jeon

A novel approach to β-trifluoromethyl enaminones

Abstract— -Trifluoromethyl enaminones 1 were prepared in good yields from the reaction of trifluoropropynyl lithium with N -methoxy- N -methylbenzamide, followed by quenching with H 2 O in the presence of a variety of amines. The use of hydrazineor benzamidine as an amine source in this reaction resulted in the formation of pyrazole 3 or pyrimidine 4 .

Preparation of 4-trifluoroethylidene-1,3-dioxolane derivatives via new stable (trifluoromethyl)ethynylation reagent

Abstract Perfluoroalkylated 4-trifluoroethylidene-1,3-dioxolane derivatives 2a – q were prepared in excellent yields from the reaction of new stable (trifluoromethyl)ethynylation reagent 1a with 1.3 equiv. of TBAF at −15°C for 10 min, followed by treatment with 2 equiv. of phenyl perfluoroalkylated ketone derivatives at room temperature. The reaction of 1a with 1.3 equiv. of TBAF, followed by treatment with 1 equiv. of aldehyde or ketone at −15°C for 10 min and then with trifluoroacetophenone (1 equiv.) at room temperature afforded perfluoroalkylated 4-trifluoroethylidene-1,3-dioxolane derivatives 2t – u in moderate yields.

A new method for the preparation of perfluoroalkylated triphenylethylene derivatives

Abstract The reaction of perfluoroalkylated dithioketals 1 with 2.1 equiv. of phenyllithium afforded the corresponding vinyl sulfides 2 in good yields. Treatment of vinyl sulfones 3 , obtained from the oxidation of 2 , with phenyllithium derivatives resulted in the formation of perfluoroalkylated triphenylethylenes 4 .