Addition to hexafluoro

Similar methodology has been used to prepare the dialkoxyphosphinyldi-fluoromethylcopper compound [242] (equation 160) Functionalization with allyl bromide, methyl iodide, and iodobenzene occurs readily, as well as stereospecific syn addition to hexafluoro-2-butyne [243]. 

Stannanes also add across double bonds offiuonnated olefins in a free radical reaction Trimethylstannane undergoes stereospecific addition to hexafluorocyclo-butene to afford trans 1,2,3,3,4,4 hexafluoro 1 (trimethylstannyl)cyclobutane [5] (equation 1)... 

Examples of photochemical methods of addition to acetylene derivatives are the addition of methyl disulfide to hexafluoro-2-butyne [7] (equation 8), of trifluaramethanethial to methyl propiolate [S] (equation 9), of methanethiol to trifluoromethylacetylene and hexafluoro-2-butyne [9] (equation 8), and of tri-methylsilane to tetrafluoropropyne [10. ... 

In addition to complex-formation, the interaction of transition-metal atoms with organic substrates at low temperatures can result in rearrangement of the organic moiety without complexation. Two such reactions have already been briefly mentioned, namely, the polymerization of hexafluoro-2-butyne by Ge and Sn atoms (72) and the polymerization of styrene by Cr atoms (i 1). In this section we shall briefly summarize some of these transition-metal-atom-promoted, organic rearrangements. 

Pentafluorophenylcopper exhibits high reactivity towards a variety of organic substrates such as aryl, vinyl, alkynyl, allyl halides etc. [226,227,229,235-238] (Scheme 77). Similar to trifluorovinylcopper, pentafluorophenylcopper readily adds to hexafluoro-2-butyne to form the syn addition product, which can be quenched with electrophiles [230] (Scheme 78). 

At reflux, tetrahydrofuran slowly adds to terminal perfluoroalkylethylenes, perfluoroalkylacetylenes, and ethyl perfluoroalkylpropynoates [25] (equation 18) By contrast, the ionic addition of enamines to hexafluoro-2-butyne is exothermic and gives dieneamines that, on acidic hydrolysis, yield fluoroalkenyl ketones [26] (equation 19)... 

Addition of hexafluoro-2-butyne to Pd(CF3COCHCOMe)2 yields Pd OC(Me)CH(COMe)-... 

Another route to neutral bisalkyne complexes is from the trifluoro-methylacyl precursor which deinserts carbon monoxide to yield trifluoro-methyl molybdenum products. Photolysis of CpMo(CO)3[C(0)CF3] in the presence of CF3C=CCF3 forms CpMo(CF3C=CCF3)2(CF3) CpMo-(DMAC)2CF3 is formed without photolysis (98). Addition of hexafluoro-butyne to CpMo(CO)(MeC=CMe)(CF3) forms the mixed bisalkyne via CO substitution. 

The adduct obtained from acetaldehyde and perfluoro-3,4-dimethylhex-3-ene on y-irradiation was transformed thermally into a fluoroalkylated furan in the presence of tributylamine (80TL1891). 4,5-Bis(trifluoro-methyl)octa-3,6-dione, the addition product of propionaldehyde to hexafluoro-2-butyne on y-irradiation, yields 2,5-diethyl-3,4-bis-(trifluoromethyl)furan on treatment with sulfuric acid (91JHC225) (Scheme 51). 

When the 3,5-dienes (504) or (505) are irradiated in pentane, under helium, the reactive bicydo butanes (506) are formed, the 3)5,5/ - and 4,6a-bonds arising by an internal cycloaddition between the two olefinic bonds. Addition of hexafluoro-acetone to the pentane solution of the bicyclobutane opened the 4,6a-bond to give the adducts (507) or (508), according to the substitution type." ... 

In the presence of hexafluoro-2-butyne, 2,3-di(trifluoromethyl) thiophene was isolated in addition to the above products, formed by the addition of C2H2S to the triple bond of 2-butyne. Methyl substitution either in the 4- or 5-position leads to the formation of only one thiophene, viz. 2,3-trifluoromethyl 5-methylthiophene in the presence of hexafluoro-2-butyne, suggesting the intermediacy of methyl thiirene. Aryl-substituted 1,2,3-thiadiazoles have been investigated by Kirmse and Horner and by Huisgen . 

Guneratne, R.D., and Burton, D.J., Preparation and functionalization of an alkenylcopper reagent formed by the syn addition of (dialkoxyphosphinyl)difluoromethylcopper to hexafluoro-2-butyne, J. Fluorine Chem., 98, 11, 1999. 

The radical addition of propionaldehyde to hexafluoro-2-butyne under y-ray irradiation leads to 4,5-bis(trifluoromethyl)octa-3,6-dione 61, which was converted into 3,4-bis(trufluoromethyl)furan 62 by treatment with H2SO4. ... 

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