Sulfones trifluoromethyl phenyl sulfone

Other aryl sulfones that can accommodate the nucleophilic addition step also react in the same way. For example, excellent results have been obtained using 3,5-bis-(trifluoromethyl)phenyl sulfones.281... 

Najera and coworkers [106,107,113] have successfully applied aromatic 3,5-bis(trifluoromethyl)phenyl (BTFP) sulfones in olefination reactions. The sulfones are readily prepared using commercially available 3,5-bis(trifluoromethyl)thiophenol and the respective precursors of the aliphatic or benzylic portion of the molecule. 

The reaction between a carbanion derived from alkyl 3,5-bis(trifluoromethyl)phenyl sulfones and aldehydes affords, with good yields and stereoselectivities, the corresponding 1,2-disubstituted alkene through the Julia-Kocienski olefination reaction. This one-pot protocol can be performed using the phosphazene base at —78 °C and has been successfully used in a high yielding and stereoselective synthesis of various stilbenes such as resveratrol [47] (Scheme 5.28). 

Other Michael acceptors that were used in addition of aldehydes were vinyl sulfones. Zhu and Lu showed that the most efficient catalyst for this reaction was catalyst C2a with 3,5-bis(trifluoromethyl)phenyl groups (Scheme 8.5). It provided the corresponding products in high yields, with good to high diastereomeric and high enantiomeric purities. Palomo and coworkers also came to the same conclusion. They also extended the scope of the addition to E-a-ethoxycarbonyl vinyl sulfones. 

Naphthalenesulfonic acid, 6-amino-4-hydroxy-5-((2-(trifluoromethyl) phenyl) azo)-, monosodium salt. See Acid red 337 Naphthalenesulfonic acid, bis-(l-methylethyl)-, sodium salt. See Sodium isopropyl naphthalene sulfonate... 

More recentiy, the use of electron-poor aryl sulfones has been successfully reinvestigated. For instance, 3,5-bis(trifluoromethyl)phenyl (BTFP)-sulfones 44 treated with a base such as KOH at room tenperature or phosphazene (P4-tBu) at -78 have proved to react efficiently with a... 

Scheme 19.18 3,5-Bis(trifluoromethyl)phenyl sulfones in Julia-Kocienski reactions.

The similar alkoxide- or hydroxide-induced trifluoromethylation was also found to work with other electrophiles. Diphenyl disulfide can be trifluoromethylated to give trifluoromethyl phenyl sulfide in 87% yield (eq 4). Methyl benzoate can be trifluoromethylated to generate 2,2,2-trifluoroacetophenone in 30% yield at temperatures between —50°C and —20°C. Trifluo-romethylcopper (CF3CU) can be generated in situ with trifluoromethyl sulfone, f-BuOK, and copper iodide (Cul), and it then further reacts with iodobenzene at 80 °C for 20 h to give a,a,a-trifluorotoluene in 26% 3neld. ... 

Another application of trifluoromethyl phenyl sulfone is in the preparation of benzenesulfonic acid (or metal benzenesulfonate) using oxygen nucleophiles. Trifluoromethyl phenyl sulfone is readily transformed into benzenesufonate salt upon treatment with an alkoxide or hydroxide (eq 6). This is particularly useful for the convenient transformation of a polymer-supported trifluoromethyl phenyl sulfone into polymer-supported sulfonic acid (or sufonate) ion-conducting materials. " ... 

Transition metal-catalysed methods for carbenoid insertion into C-H bonds remain well documented. The asymmetric intramolecular Cu(II)-catalysed C-H insertion reactions of (i) a-diazo-/ -keto esters and phosphonates and (ii) a-diazo sulfones have been described. One can note that the optimal reaction conditions have been found to be quite similar regardless of the nature of the carbenoid precursor the best conditions featured CUCI2 as Cu(II)-source, bis(oxazoline) (68) as chiral ligand and sodium tetrakis[3,5-bis(trifluoromethyl)phenyl] borate (i.e., NaBARF) as additive. Under the so-optimized reaction conditions, each of these carbenoid sources have been eonverted into five-membered cyclopentanone-based derivatives (69), whereas a-sulfonyl diazo esters (70) have led to six-membered cyclic compounds (71), thus featuring a distinct but well-known selectivity. In a related work, the asymmetric C-H insertion cyclization of (70) to (71) has also been achieved under Rh(II)-catalysis, using a combination of Rh2(5-pttl)4 (72) as chiral catalyst and menthyl ester as chiral auxiliary. As already mentioned in the previous section, allene-containing substrates (49) have been shown to undergo an intramolecular C-H insertion process under Rh(II)-catalysis. ... 

Py pyrrole, MPy 1-methylpyrrole, PPy polypyrrole, PMPy poly(l-methylpyrrole), EDOT 3,4-ethylenedioxytiophene, PEDOT poly(3,4-ethylenedioxytiophene), MT 3-methylthiophene, PMT poly(3-methylthiopliene), NaPSS sodium polystyrene sulfonate, NaDBS sodium dodecylbenzenesulfonate, NaPTS sodium para-toluene sulfonate, BSA benzenesulfonic acid, SSA 2-hydroxy-5-sulfobenzoic acid, MES 2-(Af-morpholino) ethanesulfonic acid, MOPS 3-(Al-morpholino) propanesulfonic acid, PIPES piperazine-l,4-bis(2-ethanesulfonic) acid, MeCN acetonitrile, DCE 1,2-dichloroetane, BU4NPF6 tetrabutylammonium hexafluor-ophosphate, BTPPA-CIO4 bis(triphenylphosphoranylidene)ammonium perchlorate, BTPPA-TFPB bis(triphenylphosphoranylidene)ammonium tetrakis[3,5-bis (trifluoromethyl)phenyl]borate, TPenA tetraphenylammonium... 

Najera and co-workers reported the application of 3,5-bis(trifluoromethyl)phenyl (BTFP, 9) sulfones in the modified Julia olefmation to the synthesis of various stilbenes such as resveratrol. This one-pot protocol can be performed using KOH at room temperature or the phosphazene base P4-t-Bu at -78 °C, and given a high yielding and good stereoselectivity. For example, the sulfone 85, prepared from 84 by two-steps reaction, was reacted with aldehyde 86 in the presence of P4-/-Bu in THF finished the alkene 87 in 74% yield with E/Z ratio of 98 2. 

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