%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 (Cp2ZrNt-Bu) and its analogue (ebthi)ZrNAr (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 ZrN bond to an epoxide CO 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