Trimethylsilyl pentafluorophenyl

Preparation of alkyl boranes RB(C6F5)2 which do not contain (3-hydrogens can be accomplished by transmetallation between Cp2ZrR2 and ClB(C6F5)2.48b The methyl, benzyl and trimethylsilyl methyl bis-(pentafluorophenyl) boranes have been prepared in... 

The ability of fluoro-2 -phosphanes to transform silyl ethers into fluorides was first observed during a study of the reactions of phosphorus pentafluoride and its derivatives R PF5 (n = 1, 2, 3 R = hydrocarbon group) with trimethylsilyl ethers. Subsequently, this reaction was proposed as a new method for the preparation of C-F compounds from silyl ethers or silicic acid esters with fluoro-A -phosphanes. Pentafluorophenyl-substituted fluoro-A -phos-phanes were found to react similarily, Other workers found that tctrafluoro(phenyl)-A -phos-phane. which was chosen as the most convenient reagent with regard to reactivity and stability, gave considerable amounts of elimination products, especially with primary and cyclic alcohols. Good yields of fluorinated products are obtained when stable carbocations can be formed at the site of substitution, such as in tertiary alcohols, but 2-phcnylethanol. benzyl alcohol and diphcnylmethanol, on the other hand, give only poor yields of fluorinated products ethers and polymers are the main products. ... 

In a project on electron-deficient isocyanides, Lentz studied the reactivity of pentafluorophenyl isocyanide 4a, isocyanoacetonitrile 4b, pentacarbonylchromium diisocyanomethane 4c, and 2,2,2-trifluoroethylisocyanide 4d toward bis[tris(trimethylsilyl)methyl] diphosphene 3. Combination of the reactants in pentane or diethyl ether at ambient temperature led to the formation of the expected diphosphirane imines 5a-5d as yellow crystals in moderate yields (Equation 2). For the success of this process very bulky substituents at the P=P unit and electron-withdrawing groups at the nitrogen atom are required, which is evident by the decrease of thermostability in the series 5c m 5a >5b>5d <1998JFC73, 1999ZFA1934>. 

Abbreviations Ac acetyl AIBN azobisisobutyronitrile All allyl Bn benzyl Bz benzoyl ClAc chloroacetyl DAST diethylaminosulfur trifluoride DBU l,8-diazabicyclo[5.4.0]-undec-7-ene DDQ 2,3-dichloro-5,6-dicyano-/)-benzoquinone DMDO dimethyldioxirane DMTST dimethyl(methylthio)sulfonium trifluoromethanesulfonate Fmoc 9-fluorenyl-methoxycarbonyl HDTC hydrazine dithiocarboxylate IDCP iodonium di-collidine perchlorate Lev levulinoyl MBz 4-methylbenzoyl Me methyl MEK methyl ethyl ketone MP 4-methoxyphenyl NBS iV-bromosuccinimide NIS A-iodosuccinimide Pent n-pentenyl Pfp pentafluorophenyl Ph phenyl Phth phthaloyl Piv pivaloyl PMB 4-methoxybenzyl TBAF tetrabutylammonium fluoride TBDMS tcrt-butyldimethylsilyl TBDPS tert-butyldiphenylsilyl TCA trichloroacetyl TES triethylsilyl Tf trifluoromethanesulfonyl TMS trimethylsilyl Tol 4-methylphenyl Tr trityl Troc 2,2,2-trichloroethoxycarbonyl Ts tosyl. 

Pentafluorophenyl esters are useful for with Al-trimethylsilyl amides, and of. V V-<... 

Although the nitrogen of the N = S = N group has low nucleophilicity, an intramolecular cyclization can occur in the presence of a catalyst (fluoride ion). Thus, heating of l-pentafluorophenyl-3-trimethylsilyl-l,3-diaza-2-thiaallene 170 in acetonitrile in the presence of cesium fluoride leads to 4,5,6,7-tetrafluoro-2,l,3-thiadiazole 171 (90JFC(50)359) (Scheme 157). It is assumed that 171 is formed via the intermediate pentacoordinated silicon anion, which is further transformed into the N-nucleophile with elimination of trimethylfluorosilane. 

A similar reaction of l-pentafluorophenyl-4-trimethylsilyl-2,4-diaza-l,3-dithia-2,3-butadiene 172 afforded 5,6,7,8-tetrafluoro-l,3,2,4-benzo-dithiadiazole 173... 

Tervalent phosphorus acid esters, and triphenylphosphine, attack 2-bromothiazole (34) at bromine in alcoholic solvents to give thiazole and the oxidised phosphorus compounds. A similar attack of tris(diethylamino)phosphine on the bromine atom of bromopentafluorobenzene was used to prepare a series of main-group-four pentafluorophenyl derivatives, e.g. (35). A full paper has appeared on the fluoridation of trimethylsilyl phosphites, or phosphoramidites, with sulphury chloride fluoride. The mild conditions allowed the preparation of sensitive nucleoside derivatives, e.g. (36) and (37). 

Bis(triphenyltin)dihydridobis(methyldiphenylphosphine)plati-num, see Sn-00474 Bis(triphenyltin)oxide, see Sn-00440 >Bis(triphenyltin) sulfide, Sn-00443 Bis(triphenyltin)telluride, Sn-00446 >Bis(tripropyltin) oxide, see Sn-00339 >Bis[tris(2-methyl-2-phenylpropyl)tin] oxide, see Sn-00473 Bis[tris(pentafluorophenyl)germyl]cadmium, Ge-00271 Bis[tris(pentafluorophenyl)germyl] mercury, Ge-00273 Bis[tris(pentafluorophenyl)germyl] selenide, see Ge-00275 Bis[tris(pentafluorophenyl)germyl] sulfide, see Ge-00274 [Bis[tris(pentafluorophenyl)stannyl]]mercury, Sn-00435 Bis[tris(trifluoromethyl)germanium]oxide, see Ge-00064 Bis[tris[(trimethylsilyl)methyl]stannyl]mercury, Sn-00399 Bromo( 7 -2,4-cyclopentadien-1 -yl)lead, Pb-00035 Bromo( 7 -2,4-cyclopentadien-1 -yl)tin, Sn-00086 Bromodimethylstannane, Sn-00022... 

Trimethyl(nitrato-0)germanium, Ge-00029 TrimethyI(nitrato-0)stannane, Sn-00037 Trimethylnitrooxygermane, see Ge-00029 Trimethyl(nitrooxy)stannane, see Sn-00037 Trimethyl(pentafluorophenyl)lead, see Pb-00088 Trimethyl(pentafluorophenyl)plumbane, Pb-00088 Trimethyl (pentafluorophenyl)stannane, Sn-00178 Trimethyl(2,4-pentanedianato-0,0 )tin, Sn-00157 Trimethyl(perchlorato)stannane, Sn-00032 Trimethyl(phenylethynyl)germane, Ge-00139 Trimethyl(phenylethynyl)plumbane, Pb-00101 Trimethylphenylgermane, Ge-00110 Trimethyl(phenylselenyl)stannane, Sn-00182 T rimethyl [ (pheny lsulfonyl)oxy] stannane, Sn-00180 T rimethyl(phenyltelluro)stannane, Sn-00183 Trimethyl(phenylthio)germane, Ge-00111 T rimethyl (phenylthio)stannane, Sn-00181 Trimethylphosphinogermane, see Ge-00033 >Trimethylplumbane, Pb-00019 Trimethylplumbyl, Pb-00017 (Trimethylplumbyl)acetic acid, Pb-00040 (Trimethylplumbyl)bis(trimethylsilyl)amine, Pb-00091 (Trimethylplumbyl)(cyclopentadienyl)dicarbonyliron, 5 Pb-00096... 

C20H5 HgSi 6, Bis(tris(trimethylsilyl)methyl)mercury(II), 43B, 987 C20H58B2F8P6PU2, Hexakis(trimethylphosphine)bis(M methylene)-diruth-enium(111)(Ru-Ru) bistetrafluoroborate, 45B, 866 C2iCOg0,9, Bis(tricobalt enneacarbonyDacetone, 34B, 430 C21H12F1oNi f (T -Mesitylene)bis(pentafluorophenyl)nickel(II), 46B, 802... 

Reaction of bis(cyclopentadienyl)diphenyltitanium(iv) with acetylenes affords a general route to titana-indenes. The products from the reactions with phenyl-(trimethylsilyl)ethyne and bis(pentafluorophenyl)ethyne were both characterized by single crystal Z-ray studies, and the structure of the former is shown in (6). The structure is drawn with the one double bond, because, unlike metallocyclo-pentadienes in general, the Ci—Ca bond in (6) is significantly shorter than C3—C4, which is typically aromatic. The two Ti—C bonds in (6) are similar in length but the Ti—Cx bond length in the pentafluorophenyl compound is longer, which the authors attribute to steric factors. ... 

Sulfonyldipropionitrile, cf. Figure 2.20, is structurally different from commonly used compoimds as additives for an LiMn204 cathode, e.g., tiis(pentafluorophenyl) borane (76), vinyl ethylene carbonate (77), fluoroethylene carbonate (78), hexamethyldisilaz-ane (79), tris(trimethylsilyl) borate (80), or tris(trimethylsilyl) phosphate (81). 

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