%0 Generic %A Blum, Suzanne A. %A Walsh, Patrick J. %A Bergman, Robert G. %D 2003 %T Epoxide-Opening and Group-Transfer Reactions Mediated by Monomeric Zirconium Imido Complexes %U https://acs.figshare.com/articles/dataset/Epoxide_Opening_and_Group_Transfer_Reactions_Mediated_by_Monomeric_Zirconium_Imido_Complexes/3358798 %R 10.1021/ja037267t.s001 %2 https://ndownloader.figshare.com/files/5198107 %K epoxide %K lack %K ambient temperature %K Monomeric Zirconium Imido Complexes N %K Mediated %K azazirconacyclopentane %K analogue %K acid %K ebthi %K zwitterion %K azametallacycle %K ethylenebi %K mechanism %K Bu %K dimethylphenyl %K fragment %K regio %K carbocation character %K stereochemistry %K cycloaddition reactions %K intermediacy %K process results %K Cp %K Ar %K Butylimidozirconocene %K cleavage %K tert %K Zr %K bond %X N-tert-Butylimidozirconocene (Cp2ZrNt-Bu) and its analogue (ebthi)ZrNAr (ebthi = ethylenebis(tetrahydroindenyl), Ar = 2,6-dimethylphenyl) undergo overall cycloaddition reactions at ambient temperature with epoxides that lack accessible β-hydrogens. The process results in addition of the ZrN bond to an epoxide CO bond, leading to azazirconacyclopentanes. The regio- and stereochemistry of the products implicate a stepwise mechanism, with the intermediacy of zwitterions having substantial carbocation character at the substituted carbon of the ring-opened epoxide-derived fragment. The azametallacycles undergo facile cleavage to β-amino alcohols upon addition of mild acid. %I ACS Publications