Dioxaneferrocenylimine Cyclometalated Compounds as Precursors to Novel Functionalized Di- and Tetranuclear Metallacycles Leading to 1,3-Double Palladation of an eta(5)-C5H5 Ring

作者：Marino Marta; Martinez Javier; Caamano Marcelo; Teresa Pereira Ma; Ortigueira Juan M; Gayoso Eduardo; Fernandez Alberto; Vila Jose M^*

来源：Organometallics, 2012, 31(3): 890-894.

DOI：10.1021/om2008698

Reaction of the Schiff base ligands CpFe[eta(5)-C6H2{C(H)O(CH2)(3)O}C(H)=NR] (R = 2,4,6-Me3C6H2, a; R = Cy, b) derived from the 1,2-disubstituted formylferrocene CpFe[(CHO){C(H)O(CH2)(3)O}-eta(5)-C5H3] 1, with Li-2[PdCl4] in methanol at room temperature for 48 h, gave the chlorine-bridged complexes [Pd{CpFe[eta(5)-C5H2{C(H)O(CH2)(3)O}C-(H)=NR])(Cl)}(2), 1a and 1b, after C-H activation of the cyclopentadienyl ring bearing the cyclic acetal. The reactions of 1a and 1b with the Ph2P(CH2)PPh2 diphosphines in a 1:2 ratio, plus addition of ammonium hexafluorophosphate, gave the dinucelar compounds [Pd{CpFe[eta(5)-C5H2{C(H)O(CH2)(3)O}C(H)=NR}}-(Ph2P(CH2)(n) PPh2-P,P)][PF6] 2a, 3a and 2b, 3b with the diphosphine in a chelating mode, as 1:1 electrolytes. Treatment of the latter with aqueous acetic acid gave the corresponding functionalized compounds with transformation of the 1,3-dioxane ring into a formyl group on the metalated ring, 4a, 5a and 4b, 5b. The Schiff base condensation reaction of 5b with 2-(methylthio)aniline in refluxing chloroform gave [Pd(Ph2P(CH2)(2)PPh2)-{(CPFe)eta(5)-C5H2[C(H)=NCy][C(H)=N(2-SMeC6H4]}][PF6] 6b, with regeneration of the C=N double bond, which, when treated with lithium tetrachloropalladate in methanol for 48 h, gave the novel compound [Pd(Ph2P(CH2)(2)PPh2){(CpFe)eta(5)-C5H[C(H)=NCy][C(H)=N(2-SMeC6H4]}PdCl][PF6] 7b, which is the first ferrocene metallacyde displaying 1,3-double cyclopalladation.

• 出版日期2012-2-13