HYDROZIRCONATION ISOMERIZATION - REACTIONS OF TERMINALLY FUNCTIONALIZED OLEFINS WITH ZIRCONOCENE HYDRIDES AND GENERAL-ASPECTS

Hydrozirconation of internal aliphatic olefins, with terminal oxygen-, sulfur- or nitrogen-containing functionalities, has been studied. Internally unsaturated ethers, sulfides, a phenylsulfone and an ammonium iodide underwent substantial elimination of the functional group, after rearrangement of the zirconium moiety towards the carbon bearing the heteroatoms. With aromatic olefins, acceptable yields of terminal alkylzirconiums (based on deuteriation) were usually difficult to achieve. One exception was the reaction of 1-phenyl-1-hexene with 'Cp*CpZr(H)Cl' (Cp* = eta5-C5Me5). Pronounced cleavage of the methyl-sulfur bond occurred in the hydrozirconation of 1-(1-hexenyl)-2-thiomethylbenzene. Results from deuterio- and hydro-zirconations of ordinary alkenes indicated dissociation of the metal hydride from the olefins during rearrangement.