Preparation of esters containing an β-CF3 group

Diphenylpropionic Acids as New AT1 Selective Angiotensin II Antagonists

“…Malonic esters 33 were also alkylated (R 2 I, NaH, DMF) to afford compounds 38 , which on treatment with KOH/EtOH underwent simultaneous hydrolysis and decarboxylation to give the α-alkylated carboxylic acids 35g − j , l − m . The trifluoromethyl derivative 35k was obtained by hydrolysis of 39 , which was prepared by treatment of 33 with dibromodifluoromethane in the presence of sodium hydride followed by simultaneous desethoxycarboxylation and replacement of the bromine atom by fluorine by heating with potassium fluoride in DMSO at 170 °C 3 …”

“…The trifluoromethyl derivative 35k was obtained by hydrolysis of 39, which was prepared by treatment of 33 with dibromodifluoromethane in the presence of sodium hydride followed by simultaneous desethoxycarboxylation and replacement of the bromine atom by fluorine by heating with potassium fluoride in DMSO at 170 °C. 24 Compounds 35a-e were racemic mixtures, whereas 35f-n consisted of equimolar mixtures of four diastereoisomers. The two pairs of enantiomers of the most active compounds (35g-i) were separated by flash chromatography to yield a faster (36g-i) and a slower (37g-i) eluting component (Table 3).…”

Facile stereoselective syntheses of aryl substituted α,β‐unsaturated esters containing a trifluoromethyl group

“…Among the approaches to trifluoromethylated organic compounds, halogen exchange reaction [3] and trifluoromethylation [4] are possible methods, but these suffer from low reactivity and selectivity. As a convenient strategy for the preparation and application of trifluoromethylated building blocks [5], Qing et al reported a new method for the synthesis of ethyl (Z)-3-iodo-4,4,4-trifluoro-2-butenoate 2 and its alkynylation by the Sonogashira reaction [6]; Gildas et al [7] described a stereoselective access to functional dienes containing the trifluoromethyl group via the Stille coupling of the compound 2.…”