trans-1-Sulfonylamino-2-isoborneolsulfonylaminocyclohexane derivatives: excellent chiral ligands for the catalytic enantioselective addition of organozinc reagents to ketones.
The catalytic enantioselective addition of different organozinc reagents (such as alkyl and aryl derivatives or in situ generated aryl, allyl alkenyl, and alkynyl derivatives obtained through different transmetallation processes) to simple ketones has been accomplished by using titanium tetraisopropoxide and chiral ligands derived from substituted trans-1-sulfonylamino-2-isoborneolsulfonylaminocyclohexane, producing the corresponding tertiary alcohols with enantiomeric excesses (ee) up to >99 %. A simple and efficient procedure for the synthesis of the chiral ligands used in these reactions is described.
Instituto de Síntesis Orgánica (ISO) and Departamento de Química Orgánica. Facultad de Ciencias, Universidad de Alicante, Apdo. 99, 03080 Alicante, Spain.
Vicente J
VJ
Forrat
Oscar
O
Prieto
Diego J
DJ
Ramón
Miguel
M
Yus