The metal-ligand oxidations of dibenzobicyclo[2.2.2]octatriene by lead tetraacetate – hydrogen fluoride, lead tetraacetate, thallium(III) acetate, and mercuric acetate

Abstract

The isoelectronic series lead tetraacetate -hydrogen fluoride, lead tetraacetate, thallium(II1) acetate, and mercuric acetate were used to oxidize the bicyclic olefin dibenzobicyclo[2.2.2]-octatriene. The stereochemistry of the products formed from these reactions substantiates the proposal that the first formed intermediate in these oxidations is the cis-molecular addition product of the metal and its ligand to the bicyclic olefin. Subsequent stereospecific rearrangement of the adducts in the case of the lead and thallium reagents verified the absence of the involvement of homolytic processes in the formation or decomposition of the adducts. DENNIS D. TANNER, PETER B. VAN BOSTELEN et MATHEW LAI. Can. J. Chenl. 54, 2004 (1976.On a utilisC les series isoClectroniques tetraacktate de plomb -f uorure d'hydrogene. tetraacetate de plomb. acetate de thalliurn(lI1) et acetate mercurique pour oxyder l'olefine bicyclique dibenzobicyclo[2.2.2.]octatri6ne. La sterkochimie des produits formis 2 partir de ces reactions supporte la proposition que la premier intermediaire form6 dam ces oxydations est le produit d'addition molCculaire cis du metal et de son ligand a I'olCfine bicyclique. Un rearrangement sterCospCcifique ulttrieur des adduits dans le cas des rCactifs du plomb et du thallium a permis de verifier l'absence d'une implication des processus homolytiques dans la formation ou la dCcomposition des adduits.[Traduit par le journal]

The mechanism of the reaction of lead tetraacetate–hydrogen fluoride with 1-octene

“…Stereospecific displacement of lead leads to the oxidation products observed (1,2). Consistent with this proposal, it has recently been reported (3) that the reagent, PbFz(OAc)z, when allowed to react with pregnenolone yielded a relatively stable organometalic addition product (4), C25H38F206Pb.…”

“…Consistent with this proposal, it has recently been reported (3) that the reagent, PbFz(OAc)z, when allowed to react with pregnenolone yielded a relatively stable organometalic addition product (4), C25H38F206Pb. Concomitant with the displacement of the lead a number of n~olecular rearrangements have been observed (1,2,(4)(5)(6)(7). In several of these reactions where it was structuraily possible to form fluorocarbonium ions (=C-F) by the rearrangement-displacelTaken in part from the Ph.D. dissertation of Peter Van Bostelen, University of Alberta, Edmonton, Alberta, 1972. ment of lead the formation of such intermediates seems mechanistically to be a reasonable proposal (1,4,6,7).…”