1,2-Migration of the trimethylsilyl group in free radicals

Harris, Julie M.; MacInnes, Iain; Walton, John C.; Maillard, B.

doi:10.1016/0022-328x(91)86490-h

Cited by 47 publications

(26 citation statements)

References 16 publications

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“…Those peaks not overlapped, i.e. 6, 3.95, 3.65 (2 H, dd, CH,Cl); 6, 19.91 (CH,), 28.13 (CH,), 40.68 (CH,), 52.10 (CH,Cl) and 61.81 (CH), were in good agreement with the l i t e r a t ~r e ; ~~ m/z 133 [(M -C1)+, 181, 122 (ll), 120 (14), 69 (48), 67 (22), 41 (100) and 39 (34). 5-Chloropentene was also observed in the reaction mixture (by GCMS), m/z 104 (M', 6), 69 (7), 68 (35),67 (52), 55 (84), 41 (100) and 39 (80).…”

Section: Reduction Of Isopropyl Toluene-p-sulphonate With Tributyltinsupporting

confidence: 64%

Sulphonate esters as sources of sulphonyl radicals; ring-closure reactions of alk-4- and -5-enesulphonyl radicals

Culshaw¹,

Walton²

1991

J. Chem. Soc., Perkin Trans. 2

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Section: Reduction Of Isopropyl Toluene-p-sulphonate With Tributyltinsupporting

confidence: 64%

Sulphonate esters as sources of sulphonyl radicals; ring-closure reactions of alk-4- and -5-enesulphonyl radicals

Culshaw¹,

Walton²

1991

J. Chem. Soc., Perkin Trans. 2

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“…EPR spectra obtained from the reaction of NO with cyclohexen-1-yloxytrimethylsilane (12) in cyclohexane showed the rapid development of two main radicals, 6, with a(N) = 29.5 G, and 7, a dialkylaminoxyl (Table 1). The large a(N) value of radical 6 would be compatible with an iminoxyl structure, but this is unlikely because the substrate has no appropriate hydrogens at the double bond; furthermore, two conformers would be expected whereas only one species was observed.…”

Section: Resultsmentioning

confidence: 99%

Reactions of nitric oxide and nitrogen dioxide with functionalised alkenes and dienes †

Park¹,

Walton²

1997

J. Chem. Soc., Perkin Trans. 2

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Pure nitric oxide does not add to alkenes containing acceptor or donor substituents, or to conjugated dienes, to afford -nitrosoalkyl radicals. EPR spectra show that reactions are initiated by NO 2 addition to carbon-carbon double bonds to produce -nitroalkyl radicals which combine with nitric oxide to yield -nitro-nitroso-compounds. The latter trap other radicals to afford mixtures of aminoxyl radicals and, where possible, the nitroso-compounds tautomerise to oximes which oxidise to iminoxyl radicals. EPR spectra obtained on reaction of NO-NO 2 mixtures with 2,5-dimethylhexa-2,4-diene have shown the presence of a di-tert-alkylaminoxyl plus a tert,sec-dialkylaminoxyl, providing good support for this mechanism. Product analyses have established that 2-oxo-4-methylpent-3-ene and 1-acetylcyclohexene undergo extensive oxidative degradation. For enol ethers, reaction with NO-NO 2 leads to hydrolysis giving the corresponding carbonyl compound and alcohol, followed by ketal and ester formation.

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“…Intermolecular enolate reactions of acyl silanes are also known (vide infra, Section IV.A.6). 5-and 6-haloacyl silanes also undergo radical-mediated cyclization with Brook-type migration of the silyl radical moiety to give the cyclized silyloxy radical intermediates 197 , which may in turn undergo further reaction in a tandem process, for example to form spiro or fused bicyclic products (Scheme 85) 198,199 . The acyl silane unit is thus acting as a formal geminal diradical species.…”

Section: Cyclization Reactionsmentioning

confidence: 99%