Polymer supported trans-1-phenylsulfonylamino-2-isoborneolsulfonylaminocyclohexane ligand for the titanium catalyzed organozinc addition to ketones

The catalytic enantioselective addition of different organozinc reagents, such as diethylzinc, or in situ generated phenylzinc derivatives to simple ketones was accomplished using titanium tetraisopropoxide and supported chiral ligands derived from trans-1-phenylsulfonylamino-2-isoborneolsulfonylamidocyclohexane, to give the corresponding tertiary alcohols with enantioselectivities up to >99%. A simple and efficient procedure for the synthesis of the disulfonamide monomeric ligand and the corresponding polymerization is described.

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N-{2-(2-Hydroxy-7,7-dimethylbicyclo[2.2.1]hept-1-ylmethanesulfonylamino)cyclohexyl}-4-vinylbenzenesulfonamideC24H36N2O5S2Ee = 100%[α]D25=+20.1 (c 1.1, CHCl3)Source of chirality: (+)-10-camphorsulfonyl chloride