Metallacyclen aus CO 2 und dimethylbutadien am komplexrumpf (L)Ni 0: Struktur und reaktivität als funktion der neutralliganden L

Abstract

(L) Ni(CH 2C(CH 3)C(CH 3)CH 2COO) can be synthesized either by the oxidative coupling of CO 2 and diene at the complex moiety (L)Ni, or by the exchange of neutral ligands in metallacycle I (L = N, N′-tetramethylene diamine (TMED)). X-ray analyses of the compounds with L = Ph 3P and Cy 3P show that the C 5O chains are bonded similarly, with an η 3-allyl- and a monodentate carboxylate group at the ends of the chains. Thermal investigations and reactions with π-acceptor ligands were carried out as a function of the neutral ligands L. The reaction of I with π-acidic 1,4-diazadienes leads to 3,4-dimethyl-penta(2,4)dienecarboxylic acid and simulates a partial step of a possible catalytic cycle: oxidative coupling - reductive elimination under H-shift.