850352-91-9Relevant academic research and scientific papers
Synthetic and mechanistic studies of strained heterocycle opening reactions mediated by zirconium(IV) imido complexes
Blum, Suzanne A.,Rivera, Vicki A.,Ruck, Rebecca T.,Michael, Forrest E.,Bergman, Robert G.
, p. 1647 - 1659 (2008/10/09)
The reactions of the bis(cyclopentadienyl)(tert-butylimido)zirconium complex (Cp2Zr=N-t-Bu)(THF) (1) with epoxides, aziridines, and episulfides were investigated. Heterocycles without accessible β-hydrogens undergo insertion/protonation of the C-X bond to produce 1,2-amino alcohols (X = O) and 1,2-diamines (X = NR), whereas heterocycles with accessible β-hydrogens undergo elimination/protonation to produce allylic alcohols (X = O) and allylic sulfides (X = S). Mechanistic investigations support a stepwise pathway with zwitterionic intermediates for the first reaction class and a concerted pathway for the second reaction class. Additionally, the feasibility of chirality transfer from the planar-chiral ebthi (ebthi = ethylenebis(tetrahydroindenyl)) ligand was demonstrated with a chiral analogue, (ebthi)Zr=NAr(THF) (Ar = 2,6-dimethylphenyl), 2, through the diastereoselective ring opening of meso epoxides.
