17257-71-5Relevant articles and documents
Probing the parallel resolution of Mosher's acid using a combination of quasi-enantiomeric oxazolidin-2-ones
Chavda, Sameer,Coulbeck, Elliot,Dingjan, Marco,Eames, Jason,Motevalli, Majid
, p. 1274 - 1284 (2008/12/20)
Mosher's acid (2-methoxy-2-phenyl-2-trifluoromethylacetic acid) was resolved by parallel resolution of its corresponding pentafluorophenyl active ester using a quasi-enantiomeric combination of oxazolidin-2-ones.
Synthetic application of 3,3-dichloro-1, 1, 1-trifluoroacetone (DCTFA) and 3,3,3-trichloro-1, 1, 1-trifluoroacetone (TCTFA) for trifluorolactic acid derivatives
Ishii, Akihiro,Kanai, Masatomi,Yasumoto, Manabu,Inomiya, Kenjin,Kuriyama, Yokusu,Katsuhara, Yutaka
, p. 567 - 571 (2007/10/03)
Synthetic application of 3,3-dichloro-1,1,1-trifluoroacetone (DCTFA) and 3,3,3-trichloro-1,1,1-trifluoroacetone (TCTFA) for industrially important trifluorolactic acid derivatives is described. Trifluorolactic acid was obtained by hydrolysis of DCTFA unde
Enantioselective synthesis of arylmethoxyacetic acid derivatives
Moreno-Dorado, F. Javier,Guerra, Francisco M.,Ortega, Maria J.,Zubia, Eva,Massanet, Guillermo M.
, p. 503 - 510 (2007/10/03)
The preparation of several arylmethoxyacetic acids by a sequence of asymmetric dihydroxylation and further oxidation of the resulting glycol with TEMPO/NaClO/NaClO2 is described. The scope and limitations of the reaction are discussed.
Chiral discrimination of 2-arylalkanoic acids by (1S,2R)-1-aminoindan-2-ol through the formation of a consistent columnar supramolecular hydrogen-bond network
Kinbara, Kazushi,Kobayashi, Yuka,Saigo, Kazuhiko
, p. 111 - 119 (2007/10/03)
Enantiopure cis-1-aminoindan-2-ol was selected as a basic resolving agent for racemic 2-arylalkanoic acids on the basis that its rigid cis-conformation would favor the formation of a supramolecular hydrogen-bonded column, in which chiral discrimination of the racemic carboxylate would occur. It was found that this amino alcohol possesses high resolving efficiency for a variety of racemic acids; also, X-ray crystallographic analyses of the diastereomeric salts showed that a columnar hydrogen-bond network is formed in both the less- and more-soluble diastereomeric salts, as we had expected. A detailed study on the stabilising interactions suggested that there are two that play an important role: (i) hydrogen bonding between the ammonium and hydroxy groups and the acid carboxylate, which determines the formation of the columnar network and (ii) CH...π, which influences the herringbone packing of the aromatic groups, implying that it also plays some role in chiral discrimination.
Stereoselective Synthesis of Trifluoromethylated Compounds: Nucleophilic Addition of Formaldehyde N,N-Dialkylhydrazones to Trifluoromethyl Ketones
Pareja, Carmen,Martin-Zamora, Eloisa,Fernandez, Rosario,Lassaletta, Jose M.
, p. 8846 - 8854 (2007/10/03)
The nucleophilic 1,2-addition of formaldehyde N,N-dialkylhydrazones 1, 2, and 7-10 to trifluoromethyl ketones 3a-e takes place in the absence of any catalyst or promoter to afford a series of α-hydroxy-α-trifluoromethylhydrazones (4, 5, and 11-14) in good-to-excellent yields. From the several reagents studied, optimal results were achieved using 1-(methyleneamino)pyrrolidine (2) for the synthesis of racemic adducts and (S)-l-(methyleneamino)-2-[1-(methoxy)diphenyl-methyl]-pyrrolidine (10) for the asymmetric version of the reaction. The resolving properties of the chiral auxiliary carried by 10 allowed an easy Chromatographic (flash) separation of any obtained diastereomeric mixture. Thus, a single operation rendered moderate-to-good amounts (42-75%) of optically pure adducts (S,S)-14 (de > 98%) by combining excellent chemical (82-92%) and moderate optical (51-81%) yields. Hydrazones 5 and (S,S)-14 were protected by benzylation [→ 16 and (SJS)-18] and then transformed into benzyl-protected α-trifluoromethyl cyanohydrins 21 by MMPP oxidative cleavage and into α-benzyloxy-a-trifluoromethyl aldehydes 22 by ozonolysis. Alternatively, adducts 5 and (S,S)-14 were methylated [→ 19 and (S,S)-20] and transformed into the corresponding α-methoxy-α-trifluoromethyl carboxylic acids 24 by successive ozonolysis and in situ oxidation (NaClO2, tBuOH, isobutene) of the crude a-methoxyaldehydes.
A convenient preparation of (±)-α-methoxy-α-trifluoromethylphenylacetic acid (Mosher's acid)
Chong,Loewith
, p. 2145 - 2150 (2007/10/02)
Mosher's acid can be prepared from PhC(O)CF3 via a vinylation, methylation, ozonolysis/oxidation sequence in >80% overall yield.
Hydrolytic Resolution of Tertiary Acetylenic Acetate Esters With the Lipase from Candida Cylindracea
O'Hagan, David,Zaidi, Naveed A.
, p. 947 - 949 (2007/10/02)
The kinetic resolution of a series of tertiary acetylenic acetate esters using the lipase from Candida cylindracea has been explored.Compounds 6c and the trifluoromethyl acetate 6e have been resolved with high enantiomeric enrichment.Several other tertiary acetate esters carrying a CF3 group have been investigated which proved inert to enzymatic hydrolysis.From these results and published data, we are able to propose a predictive model for identifying the preferred enantiomer of secondary and tertiary trifluoromethyl acetate esters for this lipase.
