P-fluoromethylation

The resulting triblock polymer is an ABA structure of controlled segment molecular weights. Anion coupling has been employed in the preparation of block copolymers of styrene-chloromethyl styrene(23) and styrene-p-fluoromethyl styrene( L Styrene-perfluoroethylene oligomers have also been prepared by anion coupling( ) Other... 

To obtain a formal P-fluoromethylation of ketones, Shibata, Tom, and coworkers employed FBSM (62) as Michael donor in the enantioselective conjugated addition to a,P-unsaturated ketones [87]. The reaction was catalyzed by a quaternary salt derived from cinchona alkaloid (103), affording the frnal products 104 in high yields (up to 91%) and excellent enantioselectivities (Scheme 33.29). 

At 320 °C, cesium tetrafluorocobaltate converts benzotrifluoride to /n-fluo-robenzotrifluoride, 2f/-heptafluorotoluene, octafluorotoluene, pertluoro-l -meth-ylcyclohexene, and perfluoromethylcyclohexane [29] l,3-Bis(trifluoromethyl)-benzene is convened at 420 °C to 4,5,6-trifluoro-l,3-bis(trifluoroethyl)bcnzene, perfluoro-l,3-dimethylbenzene, and perfluoro-l,3-dimethylcyclohexane [29], p-Xylene gives at 350 °C l,4-bis(difluoromethyl)tetrafluorobenzene, 1-di-fluoromethyl-3-trifluoromethyltetrafluorobenzene, perfluoro-1,3-dimethyl-benzene, and perfluoro-1,3-dimethyloyclohexane... 

Convenient syntheses of vinyl fluorides are of synthetic interest, fhe conjugate base of fluoromethyl phenyl sulfone reacts with carbonyl compounds to provide P-tluoro alcohols, which are used to prepare terminal vinyl fluorides [25] (equation 23) (Table 9) This reaction offers an alternative to the Winig reaction, which may be very sensitive to reaction conditions. 

Aniline, 2-biomo [Benzenamine, 2-bromo-], p-biomination of, 55, 23 Aniline, 3-biomo- [Benzenamine, 3 biomo-], p-biomination of, 55, 23 ANILINE, 4-bromo-/V,A -dimethyl-3-(tn-fluoromethyl)- [Benzenamine, 4-bromo-A,eAr-dimethyl-3-(trifluoro-methyl-], 55, 20... 

Aniline, 2-chloro- [Benzenamine 2-chloro-], p-bromination of, 55, 23 Aniline, 3 chloro- [Benzenamine, 3-chloro-], p bjomination of, 55, 23 Aniline, //.A -diethyl- [Benzenamine, N,N-diethyl-], p-bromination of, 55, 23 Aniline,TV,//-dimethyl- [Benzenamine, N,N-dimethyl-], p-brommation of, 55, 23 Aniline, 2,3-dimethyl- [Benzenamine, 2,3-dimethyl-], p-bromination of, 55, 23 Aniline, 2,5-dimethyl- [Benzenamine, 2,5-dimethyl-], p-biomination of, 55,23 Aniline, 3,5-dimethyl [Benzenamine, 3,5-dimethyl ], p bromination of, 55,23 Aniline, Ar,iV-dimethyl-3-(trifluoromethyl) [Benzenamine, At,Ar-dimethyl-3-tn-fluoromethyl-], 55,21 Aniline, 3-methoxy- [Benzenamine, 3-methoxy-], p-bromination of, 55, 23 Aniline, TV-methyl- [Benzenamine, //-methyl-], p-biomination of, 55, 23 Aniline, 2-methyl-//,JV-dimethyl- [Benzen-amme, 2/V,/V-tnmethyl-], p-bromina-tion of, 55, 23... 

An a-fluorinated phosphinyl sulfoxide derivative, prepared as a mixture of diastereomers by the treatment of lithiated (a-fluoromethyl)diphenylphosphine oxide with menthyl p-toluenesulfinate, has been used for the preparation of enan-tiomerically pure 1-fluorovinyl and 1-fluoromethyl sulfoxides [76]. (E)-Diethyl ferf-butylsulfinylmethylphosphonate 117 has been prepared by the sulfinylation... 

Ethyl substitution at the imidazole 5-position (469) was found to increase potency over the unsubstituted analogue (468), while methyl substitution (470) had a slightly deleterious effect on binding (Table 6.41). Chloro (491), bromo (492), cyano (493) and fluoromethyl (494) substitution at this position were all well tolerated (Table 6.43). Introduction of a chloro-substituted pyridine (475) in place of the more usual / -chlorophenyl group (470) resulted in a slight loss of affinity for the CBi receptor, as did replacement of the p-chloro group of (470) with bromo (471), fluoro (472) and in particular, met-hoxy (473). Trifluoromethyl substitution (474) however, was well tolerated. 

A solution of 10.5 g. (0.046 mol) of freshly distilled bis(tri-fluoromethyl)-l,2-dithiete (Note 2) in 200 ml. of n-pentane is cooled to —10° in a 1-1. round-bottomed flask equipped with an efficient reflux condenser and protected from moist air by a dry nitrogen blanket. A solution of 3.0 ml. (0.023 mol) of nickel carbonyl dissolved in 100 ml. of w-pentane is added down the condenser in one portion to this solution. The mixture is swirled to mix. An intense blue-violet color develops in about 15 to 20 seconds and after 1 to 2 minutes, vigorous evolution of carbon monoxide occurs. This evolution subsides in 10 minutes and the deep violet solution is allowed to warm to 0° during 2 hours to ensure complete reaction. Most of the pentane is removed by distillation at atmospheric pressure, the remaining 50 to 60 ml. is removed in vacuo (0.1 mm.), and the resultant crystalline mass is evacuated (0.1 mm.) at 50° for 4 hours. The crude product consists of shiny black-purple needles and weighs 11.8 g. (98%). Recrystallization from dry benzene (Note 3) gives shiny black crystals, m.p. 134 to 135° (sealed tube). The complex is air-stable but should be kept out of contact with moist air. 

J. R. McCarthy, D. P. Matthews, and J. P. Paolini 209 REACTION OF SULFOXIDES WITH DIETHYLAMINOSULFUR TRIFLUORIDE PREPARATION OF FLUOROMETHYL PHENYL SULFONE, A REAGENT FOR THE SYNTHESIS OF FLUOROALKENES... 

Initially choline, (CH3)3N+CH2CH20H = trimethyl-2-hydroxyethylamminium, was introduced for tumor imaging labeled with [ C] by Hara et al. [175,176]. However, the short half-life of [ C] (20 min) limits its use in institutions with a cyclotron on site. This led to the development of [ F] (half-life 110 min) labeled choline taking also advantage of the better physical properties for imaging of F compared with [ C] [178]. Two compounds of p F]-labeled choline analoga are currently in use 2-[ F]-fluoroethyl-dimethyl-2-hydroxyethyl-ammo-nium ([ F]-FEC) and [ F]-fluoromethyl-dimethyl-2-hydroxyethylammonium choline (p F]-FCH) [178,179]. 

P.W. Collins, R.L. Shone, A.F. Gasieski, W.E. Perkins, R.G. Blanch , Stabilization of a prostaglandin tertiary allylic alcohol system by fluorine Synthesis, acid stability studies and pharmacology of a 16-fluoromethyl analog of SC-46275, Bioorg. Med. Chem. Lett. 2 (1992) 1761-1766. 

The Henry nitro-aldol condensation involves the use of P-amino alcohols as the building blocks of fluoromethyl ketones. Although this method has been used extensively in the synthesis of monofluoropeptides (Table 2),19-121 it is more widely utilized as a method for synthesizing trifluoromethyl ketones and the details of the reaction will be discussed in Section 15.1.4.3.2. 

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