. "Meunier, P." . "Mach, Karel" . . . "4"^^ . "11"^^ . . "RIV/61388955:_____/05:00000579" . . "The five new silanes C5Me3RSiMenCl3-n (n = 3, R = i-Pr (5); n = 2, R = i-Pr (6); n = 2, R = s-Bu (7); n = 2, R = cyclohexyl (8); and n = 3, R = t-Bu (9)) were synthesized by reaction of 1-alkyl-2,3,4-trimethylcyclopentadienyl lithium salts with appropriate chlorosilane and characterized by NMR, MS, and IR spectra. At elevated temperatures (250-360 K), all the silanes undergo a nondegenerate sigmatropic silyl rearrangement, which generates non-equivalent structures a and b. The presence of minor structure c was observed in compounds 5 and 7 only. The Diels-Alder cycloaddition of 5 with strong dienophiles tetracyanoethylene (TCNE), and dimethylacetylenedicarboxylate (DMAD) provides compounds 10 and 11, which confirmed isomers a and b, respectively. The free energy of activation of b a isomerization for compounds 5-8 evaluated from variable temperature NMR spectra show only marginal influence of group R on the 1,2-silyl shift rate."@en . "532973" . "\u010Cejka, Ji\u0159\u00ED" . "Non-degenerate 1,2-silyl shift in silyl substituted alkyltrimethylcyclopentadienes" . "Non-degenerate 1,2-silyl shift in silyl substituted alkyltrimethylcyclopentadienes" . "Kubi\u0161ta, Ji\u0159\u00ED" . . . "Pinkas, Ji\u0159\u00ED" . . "6"^^ . "Nedegenerovan\u00FD 1,2-silatropn\u00ED p\u0159esmyk v alkyltrimethylcyklopentadienech substituovan\u00FDch silylov\u00FDmi skupinami"@cs . "Non-degenerate 1,2-silyl shift in silyl substituted alkyltrimethylcyclopentadienes"@en . . "Gyepes, R." . "3" . "The five new silanes C5Me3RSiMenCl3-n (n = 3, R = i-Pr (5); n = 2, R = i-Pr (6); n = 2, R = s-Bu (7); n = 2, R = cyclohexyl (8); and n = 3, R = t-Bu (9)) were synthesized by reaction of 1-alkyl-2,3,4-trimethylcyclopentadienyl lithium salts with appropriate chlorosilane and characterized by NMR, MS, and IR spectra. At elevated temperatures (250-360 K), all the silanes undergo a nondegenerate sigmatropic silyl rearrangement, which generates non-equivalent structures a and b. The presence of minor structure c was observed in compounds 5 and 7 only. The Diels-Alder cycloaddition of 5 with strong dienophiles tetracyanoethylene (TCNE), and dimethylacetylenedicarboxylate (DMAD) provides compounds 10 and 11, which confirmed isomers a and b, respectively. The free energy of activation of b a isomerization for compounds 5-8 evaluated from variable temperature NMR spectra show only marginal influence of group R on the 1,2-silyl shift rate." . . . . "Z(AV0Z40400503)" . "[E929CF519035]" . "substituted cyclopentadienes; silatropic shift; dynamic NMR spectroscopy"@en . "RIV/61388955:_____/05:00000579!RIV06-AV0-61388955" . . "Non-degenerate 1,2-silyl shift in silyl substituted alkyltrimethylcyclopentadienes"@en . . . "Journal of Organometallic Chemistry" . "731;741" . "Nedegenerovan\u00FD 1,2-silatropn\u00ED p\u0159esmyk v alkyltrimethylcyklopentadienech substituovan\u00FDch silylov\u00FDmi skupinami"@cs . . "P\u011Bt nov\u00FDch silan\u016F obecn\u00E9ho vzorce C5Me3RSiMenCl3-n (n=3, R=i-Pr (5); n=2, R=i-Pr (6); n=2, R=s-Bu (7); n=2, R=cyklohexyl (8); n=3, R=t-Bu (9)) bylo p\u0159ipraveno reakc\u00ED 1-alkyl-2,3,4-trimethylcyklopentadienyl lithn\u00E9 soli s p\u0159\u00EDslu\u0161n\u00FDm chlorsilanem a charakterizov\u00E1no metodami NMR, MS a IR. Ve v\u0161ech p\u0159ipraven\u00FDch silanech doch\u00E1z\u00ED k nedegenerovan\u00E9mu silatropn\u00EDmu p\u0159esmyku, vedouc\u00EDmu k rozd\u00EDln\u00FDm izomer\u016Fm a a b a to ji\u017E p\u0159i teplot\u00E1ch nad 250 K. Ve slou\u010Denin\u00E1ch 5 a 7 byla nav\u00EDc dok\u00E1z\u00E1na p\u0159\u00EDtomnost izomeru c. Diels-Alderova reakce slou\u010Deniny 5 se siln\u00FDmi dienofily tetrakyanoethylenem (TCNE) \u010Di dimethylacetylendikarboxyl\u00E1tem (DMAD) vedla ke slou\u010Dnin\u00E1m 10 a 11, co\u017E potvrdilo p\u0159edpokl\u00E1danou strukturu izomer\u016F a a b. Hodnoty standardn\u00ED Gibsovy energie pro izomerizaci b->a, z\u00EDskan\u00E9 z teplotn\u011B z\u00E1visl\u00FDch NMR m\u011B\u0159en\u00ED slou\u010Denin 5-8, ukazuj\u00ED na pom\u011Brn\u011B mal\u00FD vliv alkylov\u00E9 skupiny R na rychlost 1,2-silatropn\u00EDho p\u0159esmyku."@cs . . "CH - \u0160v\u00FDcarsk\u00E1 konfederace" . . "690" . "0022-328X" .