| Abstract
| - The reactions of the bis(cyclopentadienyl)(tert-butylimido)zirconium complex (Cp2ZrN-t-Bu)(THF) (1) with epoxides, aziridines, and episulfides were investigated. Heterocycleswithout accessible β-hydrogens undergo insertion/protonation of the C−X bond to produce1,2-amino alcohols (X = O) and 1,2-diamines (X = NR), whereas heterocycles with accessibleβ-hydrogens undergo elimination/protonation to produce allylic alcohols (X = O) and allylicsulfides (X = S). Mechanistic investigations support a stepwise pathway with zwitterionicintermediates for the first reaction class and a concerted pathway for the second reactionclass. Additionally, the feasibility of chirality transfer from the planar-chiral ebthi (ebthi =ethylenebis(tetrahydroindenyl)) ligand was demonstrated with a chiral analogue, (ebthi)ZrNAr(THF) (Ar = 2,6-dimethylphenyl), 2, through the diastereoselective ring opening ofmeso epoxides.
- Imidozironium complexes react with three-membered heterocycles in two ways: if heterocycle substituents with β-hydrogens are present, concerted hydrogen transfer/ring opening occurs to give alkoxy complexes and then allylic alcohols, but when no β-hydrogens are accessible, stepwise ring opening via zwitterions occurs (see drawing), leading after protonation to 1,2-amino alcohols.
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