Chiral mercaptoaryl-oxazolines as ligands in asymmetric catalysis: Enantioselective Cu-catalyzed 1,4-addition of Grignard reagents to α,β-unsaturated ketones
作者:Qi-Lin Zhou、Andreas Pfaltz
DOI:10.1016/s0040-4039(00)61549-6
日期:1993.11
Copper(I) thiolate complexes derived from chiral mercaptophenyl-oxazolines 3 have been studied as enantioselective catalysts for the 1,4-addition of Grignard reagents to α,β-unsaturated ketones. For cyclic enones enantioselectivities increase in the sequence cyclopentenone (16–37% ee) < cyclohexenone (60–72 % ee) < cycloheptenone (83–87% ee).
Chiral mercaptoaryl-oxazolines as ligands in enantioselective copper-catalyzed 1,4-additions of Grignard reagents to enones
作者:Zhou Qi-Lin、Andreas Pfaltz
DOI:10.1016/s0040-4020(01)89379-0
日期:1994.4
A series of chiral enantiomerically pure mercaptoaryl-oxazolines has been synthesized. Copper(I) thiolate complexes derived from these ligands proved to be efficient catalysts for the 1,4-addition of Grignard reagents to cyclic enones. Enantioselectivities increased in the sequence cyclopentenone (16–37% ee) < cyclohexenone (60–72% ee) < cycloheptenone (83–87% ee).
Enantioselective palladium catalysed allylic substitution. Electronic and steric effects of the ligand.
作者:Joanne V Allen、Justin F Bower、J.M.J. Williams
DOI:10.1016/s0957-4166(00)86260-6
日期:1994.10
Ligands containing an enantiomerically pure oxazoline and a sulfur-containing tether have been examined for their ability to provide asymmetric induction in palladium catalysed allylic substitution reaction. The enantioselectivity obtained was found to be highly dependent upon the stereochemistry at sulfur (for sulfoxides), and also somewhat dependent upon the nature of the aryl group attached to the