ChemInform Abstract: ON ATTEMPTS AT SOLVOLYTIC GENERATION OF ARYL CATIONS

Subramanian, L. R.; Hanack, M.; Chang, Lih-Wie; Imhoff, Michael A.; Schleyer, P. Von R.; Effenberger, Franz; Kurtz, Walter; Stang, Peter J.; Dueber, Thomas E.

doi:10.1002/chin.197715077

Cited by 1 publication

(1 citation statement)

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“…Magic acid, SO2C1F, Freon, bromomesitylene (5) (all from Aldrich), cupferron (6), triflic anhydride, methyl triflate (all from Fluka), nonafluorobutane sulfonyl fluoride (Buyer) and H2lSO (60% '*O Stohler Isotope Chemicals) were used as received. Phenylazoxy p-toluenesulfonate (1) [23], phenyl triflate (4) [8], 4-chlorophenyl triflate (13) [8], 4,4'-biphenyl ditriflate (14) [8] and phenyl N, N-dimethylsulfamate (10) [30] were prepared by known methods.…”

Section: Experimental Partmentioning

confidence: 99%

Attempts at Solvolytic Generation of Phenyl Cations

Laali¹,

Szele²,

Yoshida³

1983

Helvetica Chimica Acta

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SummaryNew substrates and reaction conditions which may be expected to yield phenyl cation intermediates have been investigated. The approaches used were: ( a ) solvolysis of PhX in fluorinated alcohols, where X = -N (O)= NOTs (tosyloxyazoxy), -N (O)= NONf (Nf= C4F9S0T) and -OSO$ (CH3)30Tf (Tf= CF3S0,); (b) solvolysis of ArBr, PhOTf and Ph0SO2fi(CH3),OTf (phenyl 'betylate triflate') in superacid solvents (FS03H . SbF5, SbF5, AgSbF6). Analysis of the Rroduct mixtures provided no evidence for the intermediacy of phenyl cations as a major pathway in any of the reactions. This result is remarkable, since the 'betylate', for example, is a better leaving group by a factor of at least lo5 than the 'super' leaving group triflate in the solvolysis of alkyl sulfonates. These results are a further indication of the extremely low stability of phenyl cations, as well as of the very special properties of the nitrogen leaving group in arenediazonium ions.Introduction. -The solvolytic formation of aryl cations as intermediates in the heterolytic dediazoniation of arenediazonium ions is well documented [ 1-61. On the other hand, all attempts at producing phenyl cations by solvolyzing arenesulfonates with 'super' leaving groups, for example trifluoromethanesulfonates (triflates) and nonafluorobutanesulfonates (nonaflates) in polar non-nucleophilic solvents have failed up to now [7] [S].

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