Nickel‐katalysierte Isomerisierung von Butadien‐Hydrazon‐Misch‐Oligomeren. Vorläufige Mitteilung

Abstract

Nickel-catalysed Isomerization of Unsaturated Azocompounds SummaryUnsaturated azocompounds, produced by the nickel-catalysed reaction of butadiene with hydrazones, can be isomerized in presence of the same nickel catalyst. The influence of nickel concentration, temperature and structure of the azocompound on this rearrangement is described.Es ist bekannt, dass die nickel-katalysierte Misch-Oligomerisierung von Butadien mit Mono-alkyl-und -aryl-hydrazonen zu Azoverbindungen mit verzweigter oder h e a r e r Oktadienkette fuhrt Zwischen den beiden Formen wird hier nicht unterschieden.

Nickel-catalysed reactions of olefins with =C=N- double bond systems

“…With extended reaction times the amount of the linear isomer F increases very strongly, which suggests an ensueing rearrangement E -F (12). Such a nickel-catalysed isomerisation of butadiene-oligomers has previously been described only for 1,2-divinylcyclobutane, which rearranges to 1,5-cyclooctadiene and 4-vinylcyclohexene (13).…”

Nickel Catalyzed Oligomerization of Alkenes and Related Reactions

“…Isoprene formation is initiated by Ni -* C2 addition followed by rearrangement through a (cyclopropylmethyl)nickel intermediate (Scheme 5) while 1,4-hexadiene formation involves Ni -* C\ addition followed by C-C cleavage to give an r; 3 A rearrangement which might be related to those discussed above is the conversion of 3-substituted l,6(or l,7)-octadiene derivatives into the linear isomer (e.g. equation 21) 91 which is catalyzed by [Ni(cod) 2 ]-PPh 3 .…”

Nickel Catalyzed Oligomerization of 1,3-Dienes and Related Reactions

“…89 Octadienylated methylhydrazones have also been shown to be formed in a stoichiometric reaction between [NiPPh 3 (77 3 ,77 3 intermediates involved are possible and it has, moreover, been suggested that the /3-hydrogen transfer step occurs as a sigmatropic rearrangement within the complex without involving the nickel atom. 72 Complexes related to the intermediates shown in the Scheme have been isolated from the stoichiometric reaction between [Ni(cod)2], 1,3-dienes and Schiff bases.…”