On the mechanism of the reductive cleavage of anti-9-phenyl-cis-bicyclo[6.1.0]nona-2,4,6-triene

Treatment of the title compound (1a) with potassium in liquid ammonia at ca ?33° immediately afforded the benzylcyclooctatetraene dianion (4a) which, upon quenching with iodine-pentane, gave benzylcyclooctatetraene (5) as the only isolable product. In contrast, treatment of1a with potassium amide in liquid ammonia at ?69° initially afforded the 9-phenylmethylenecyclooctatrienyl anion (6a) as a short-lived intermediate which was then converted to the α-aminobenzylcyclooctatetraene dianion (7a). These results, coupled with the observation that cis-bicyclo[6.1.0]nona-2,4-diene (12) in potassium amide-liquid ammonia affords the cis-bicyclo[6.1.0]nonadienyl anion (8b) which then slowly opens to the methylcyclooctatetraene dianion (4b) at ?12°, lead to the conclusion that4a is produced by a reductive cleavage of1avia a radical anion or dianion.     

9-Phospha-bicylco [6.1.0] nona-2,4,6-triene 9-Phospha-bicylco [4.2.1.] nona-2,4,7-triene

The synthesis of the title compounds with substituents R=Alkyl, Cl, H by reaction of COT^2? with RPCl₂ at ?70°C is described.     

The synthesis of bicyclo[6.2.0]decapentaene

The parent bicyclo[6.2.0]decapentaene is synthesized for the first time by thermal ring opening of its valence isomer. Thermal dimerization of the compound is also described.     

Sequential thermal rearrangements of syn-9-vinyl-bicyclo[6.1.0]-nona-2,4,6-triene

The title compound 1-syn at 65°C undergoes a cascade of thermal rearrangements to yield tetracyclo[5.4.0.0.^2,11O^4,10]undeca-5, 8-diene (5). The kinetics for the isomerization of the intermediate bicyclo(4.3.2]-undeca-2,4,7,10-tetraene (3) have been measured.     

NMR study of the sigmatropic [1,3]-B shift in 7,8-dipropyl-7-borabicyclo[4.2.2]deca-2,4,9-triene

Activation parameters of the interconversion of geometric isomers6a and6b were determined by a complete lineshape analysis of the temperature-dependent¹³C NMR spectra of 7,8-dipropyl-7-borabicyclo[4.2.2]deca-2,4,9-triene (6). For the reaction6a 6b, G ₂₉₈ = 52.2±0.1 kJ mol^–1, H = 27.9±0.5 kJ mol^–1, S = –82±8 J mol^–1 K^–1; For the reaction6b 6a, G ₂₉₈ = 52.6±0.1 kJ mol^–1, H = 24.7±0.5 kJ mol^–1, S = –93±10 J mol^–1 K^–1. The interconversion of deuteropyridine complexes9a and9b proceedsvia their dissociation, which indicates that the rearrangement of borane6 occurs according to the [1,3]-B shift mechanism.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2243–2250, September, 1996.     

N-Amino-endo-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide in reaction of oxidative aminoaziridination

The ability of easily accessible N-amino-endo-bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide to undergo oxidative addition to double bonds of alkenes has been explored. The compound is active toward alkenes with electron-withdrawing groups, aryl- and alkyl-substituted alkenes, providing access to stable derivatives of N-aminoaziridine. Yields varied from 20% to 70%. No products of self-aminoaziridination were isolated.     

Intramolecular diels-alder reaction of bicyclo[6.4.0] dodeca-4,9,11-triene

cis-Bicyclo[6.4.0]dodeca-4,9,11-triene (5) has been synthesized and the kinetics of its intramolecular Diels-Alder reaction have been measured from 50–75°C