Reactions of C,N-chelated Tin(II) and Lead(II) Compounds with Zirconocene Dichloride Derivatives

The reactions of a C,N-chelated ((LCN)2M, where LCN is 2-((dimethylamino)methyl)phenyl and M is Sn (1) or Pb (2)) stannylene and plumbylene with di-n-butylbis(η5-cyclopentadienyl)zirconium (3) were studied. In the case of the stannylene, the trinuclear carbene-like complex [(LCN)2Sn]2Cp2Zr (4) was isolated as the major product. The second product isolated resulted from transmetalation of the C,N-chelating ligand from tin to zirconium, followed by 1-butene coupling to the coordinated aryne (C,N-chelating ligand) (5). In the lead case, the major product was the complex 5. Byproducts were elemental lead, the free ligand (LCNH), butane, and 1-butene. The oxidation of 4 by oxygen gave the six-membered trioxa trizircona cyclic complex (6) and an eight-membered tetraoxa tetrastanna cyclic complex (7).