The C2 selective nucleophilic substitution reactions of 2,3-epoxy alcohols mediated by trialkyl borates:: The first endo-mode epoxide-opening reaction through an intramolecular metal chelate

[GRAPHICS] Highly efficient C2 selective substitution reactions of 2,3-epoxy alcohols with nucleophiles were developed by using NaN3-(CH3O)(3)B, NaSPh(CH3O)(3)B, or NaCN-(C2H5O)(3)B system. The reaction proceeds through novel endo-mode epoxide opening of an intramolecular boron chelate, which was suggested from both experimental and quantum mechanic studies.