Alkyl pentachlorophenyl

Table 21 Reactions of alkyl pentachlorophenyl sulfones with aldehydes...

Arylgold(I) compounds can be similarly prepared to alkyl derivatives via the organolithium or the Gridnard route. These methods have been used to prepare pentachlorophenyl,1641 4,4 -octa-fluorobiphenyl (Equation (27)),2109 2,4,6-tris(trifluoromethyl)phenyl,1 2,21 0 triphenylar-... 

Perfluoroalkylcopper and perfluoroarylcopper compounds are noticeably more thermally stable than the corresponding alkyl and aryl compounds. Solutions of perfluoroalkylcopper compounds in DMSO or DMF are stable up to at least 120°C 200), whereas ether suspensions of alkylcopper compounds decompose at 0°C or below. Similarly, pure pentafluorophenylcopper tetramer decomposes at 210°C-220°C, and a sample has been kept in a Dry Ice chest for 5 years 32). However pure phenylcopper can be kept for no more than a few days, even under nitrogen 73). Solutions of pentafluorophenylcopper reagents containing metal halides in THF have been refluxed for 5 days or more without decomposition (97, 144). Other stable perhaloarylcopper reagents are those in which the aryl moiety is perfluoro(p-phenoxyphenyl) (96), pentachlorophenyl, and 2,3,5,6-tetrachloropyridyl 144), none of which... 

Aminopyridine is reported to react vigorously with chlorosulfonyl isocyanate at 0°C producing an urea intermediate (12) which in the presence of diisopropylethylamine was shown to yield pyrido[l,2-i][l,2,4,6]thiatriazine-5(6/0 OIte-l l-dioxide (2) (Scheme 3) <79H(6)815>. Its V-benzyl derivative (3) was selectively prepared by the reaction of 2-benzylaminopyridine (13) with either chlorosulfonyl isocyanate via intermediate (15) or pentachlorophenyl chlorosulfonyl carbamate (PCPCSC) in the presence of diisopropylethylamine via intermediate (14) (Scheme 4) <86H(8)2255>. The reaction of 2-alkyl-2-chlorosulfonyl carbamoyl chlorides with 2-aminopyridine resulted in 2-alkylpyrido [l,2-i ][ 1,2,4,6]thiatriazine-3(2/0-one-1,1-dioxides (5) (Equation (2)) <77CR(S)238>. 

Reaction of most enolates with MeOTf or Me0S02F is always likely to be kinetically controlled. There does not appear to have been a definitive study, but 0-alkylation is the normal outcome. O-Alkylation of a bicyclodecatrienone by Me0S02p is enhanced by the use of polar solvents like HMPA. O-Alkylation of enolates of appropriate cyclohexadienones by MeOTf has been used to generate various 3ai/-indenes. A ketene acetal is formed by exclusive 0-alkylation of the sodium enolate of isopropyl bis(pentachlorophenyl)acetate by MeOTf. ... 

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