Trifluoromethyl analog

Pyrrolidines obtained from trifluorocrotonates have been used to synthesize new fluoroquinolones. Starting from the trifluoromethyl analog of Hagemann s ester, it is possible to prepare a perhydroisoindolone with an angular trifluoromethyl substituent. ... 

Although quinazolin-4(3//)-one itself does not undergo photochemical intramolecular [2 + 2] cycloaddition to alkenes, its 2-(trifluoromethyl) analog does perform such a reaction. Thus, irradiation of 2-(trifluoromethyl)quinazolin-4(3i/)-one in methanol under bubbling ethene gives the [2 + 2] cycloadduct, 2a-(trifluoromethyl)-2,2a-dihydro-l/y-azeto[l,2-a]quinazolin-4(377)-one as the sole product. In several cases, the initially formed adduct of 2-(trifluo-romethyl)quinazolin-4(3/7)-one with alkenes is further transformed under the irradiation conditions." ... 

Thus, although bis(phenylseleno)methane3 >3 and its bis(m-trifluoromethyl) analogs are almost quantitatively metallated with lithium diisobutyramide or LDA in THF, respectively (Scheme 21, b and c ... 

Since the original report on the utility of Me3SiCF3 in 1989 [65], the general method has been widely used for synthesis of trifluoromethylated analogs of a variety of natural products, for example carbohydrates, nucleotides [74], and steroids (Scheme 2.129). 

As far as the basic system is concerned, KDA in THF-4iexane (a 1 1 mixture of lithium diisoprq>yl-amide (LDA) and potassium t-butoxide) > is by far more efficient than lithium tetramethylpiperidide (LiTMP) (in THF-HMPA or THF-hexane 72) which is in fact at least a power of 10 more reac-tive -56 than lithium amides (in HMPA- or THF-bexane3W6-- i 3< -W - 2- W 2 3.95.97.99,ioi-J03). Thus, although bis(phenylseleno)methane and its bis(m-trifluoromethyl) analogs are almost quantitatively metallated with lithium diisobutyramide or LDA in THF, respectively (Scheme 21, b and c ... 

Under conditions of thermodynamic control the enantio-complementary nature of the FruA-RhuA biocatalyst pair enables construction of mirror image products 78 and ent-78 from racemic 3-hydroxybutanal 77 with similar selectivity, but preference for opposite enantiomers [25]. The all-equatorial substitution in the predominant product can facilitate its separation by crystallization so that the remaining mixture can be re-subjected to further equilibration to maximize the yield of the preferred isomer 78 [177]. This general technique has recently found an application in a novel approach for the de novo synthesis of 4,6-dideoxy sugars such as 4-deoxy-r-fucose 81 or its trifluoromethylated analog (Figure 5.37) [25]. 

A number of AFLC molecules showing an AF (SmCA ) phase have b n synthesized and an attempt to correlate the molecular structure of the AFLC molecules to the appearance of the SmCA phase has been carried out. However, only a limited number of AFLC moleoiles have been reported, containing a chiral alkyl terminus with a single stereogenic center such as MFIPOBC and the trifluoromethyl analog TFMHPOBC, wherein the odd-even effect is often observed (21). The characteristic phase of AFLC, SmCA, appears in the molecules with an even numbered (n) alkyl chain. Hie SmC phase of FLC appears in molecules with an odd n. 

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