Journal of Molecular Catalysis A-Chemical, Vol.232, No.1-2, 9-12, 2005
Reversal of stereochemistry by adding Ti((OPr)-Pr-i)(4) in the enantioselective phenylacetylene addition to aldehydes using L-prolinol-backbone ligand
Chiral ligands 1-2 with L-prolinol backbone have been applied to the enantioselective phenylacetylene addition to aldehydes, providing chiral propargylic alcohols in high yields and moderate enantioselectivities. Only the ligand 1 in combination with Ti((OPr)-Pr-i)(4) afforded the products with opposite absolute configuration in significant enantiomeric excesses and high yields. The ratio of Ti((OPr)-Pr-i)(4) to the ligand had great influence on the enantiomeric excess of the product. (c) 2005 Elsevier B.V. All fights reserved.
Keywords:reversal of stereochemistry;enantioselective alkynylzinc addition;L-prolinol-backbone;propargylic alcohol;aldehyde